The Assessment of Environmental Effects for the Timberlands West Coast sustainable beech management proposals of 1998 - 1999, written by Kit Richards. Timberlands West Coast Limited (New Zealand) (TWC) applied to the Buller and Tasman District Councils for Resource Consent hearings under the Resource Management Act 1991, to carry out sustainable forest management in about 98,000 hectares of beech (Nothofagus) forest. TWC is a State Owned Enterprise, created following the dis-establishment of the NZ Forest Service by the 1984 - 1990 Labour Government. In 1999, a newly elected Labour government, acting on preservationist dogma, moved swiftly to stop the Resource Consent hearings. In consequence, the public of New Zealand, and the world, was enied the oppertunity to learn about the excellent and world-leading sustainable forest management developed and proposed by TWC. This document is published here to help make the information more publically accessible.

Assessment of Environmental Effects




Page three of this document.

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3.1 Silvicultural System

TWCL has adopted a silvicultural philosophy known as ‘natural forest management’ (Bruenig, 1996). This aims to manage the forest sustainably by selecting and harvesting widely scattered small groups of trees in order to retain a near natural forest structure across all forest management areas. It represents a clear departure from the traditional thinking concerning beech management.

The international objectives for natural forest management given by Bruenig (1996) include:

"management should aim at forest structures which keep the rainforest ecosystem as robust, elastic, versatile, adaptable, resistant, resilient, and tolerant as possible;…. canopy openings should be kept within the limits of natural gap formation; stand and soil damage must be minimised; felling cycles must be sufficiently long and tree marking so designed that a selection forest canopy structure and a self regulating stand table are maintained without, or with very little, silvicultural manipulation; production of timber should aim for high quality and versatility…… The basic principle is to mimic nature as closely as possible to make profitable use of the natural ecosystem dynamics and adaptability, and reduce costs and risks…..".

The change in approach is a response to forestry, ecological and political issues that face managers of natural forests both in New Zealand and internationally. These include:
  • Recognition of New Zealand's responsibility for maintaining the integrity, natural character and biodiversity of its remaining indigenous forests.
  • Recognition of the pre-eminence of the Resource Management Act 1991 (RMA) and its requirement for sustainable resource use that avoids, remedies, or mitigates any adverse effects of activities on the environment.
  • Concerns raised by the Parliamentary Commissioner for the Environment (1995) over the company's previous management plan – "whether uniform coupe systems are compatible with maintenance of the ecological and wildlife resources of the forests". In particular, whether the loss of rata, podocarps and large beech trees will impact on certain threatened bird species.
  • TWCL's harvesting, sawing, and economic studies, and five years' experience with sustainable podocarp management, all of which indicated that natural forest management can produce an adequate return without the need for intensive silvicultural practices, such as thinning, to enhance timber quality.
The systems of forest management selected are designed to ensure that any changes that do occur as a result of management for timber will be within the range of short period, small

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spatial scales of natural disturbance events and rendered largely irrelevant by the large scale long period events such as earthquakes that occur from time to time.

Sustainable forest management in natural forests is a concept not well understood by the public and a large percentage of professionals and scientists. This is particularly so in New Zealand where past use of native forest has been on an exploitative basis. Contemporary understandings of sustainable forest management revolve around the very intensive and artificial nature of NZ’s plantation cropping which is considerably different from the management system being applied for as part of this application.

To deal with the biological constraints of the beech forest ecosystems in the formulation of workable forest management prescriptions (working practices), an extensive range of research has been reviewed or undertaken. This work was commissioned in order to establish hard data on actual known or expected impacts from varying approaches to management. The purpose was to ensure that the timber producing systems ultimately adopted would provide the best possible integration between ecological, economic and social factors required to achieve a holistic and safe starting point for a sustainable system.

The key to sustainable resource use is that rates of change be managed to the extent that any disturbances are within the range of normal, frequent small scale natural disturbances that are in constant play. If this is achieved then such influences as arise from management will be rendered insignificant by the occasional much larger natural disturbances that occur from time to time, particularly in such a geologically and climatically active region as the West Coast. At these low levels of impact and disturbance it is also likely that long run change trends will be as much a response to external influences, e.g. global warming and predators, as they will be to timber management.

3.2 The Theory of the System

3.2.1 Natural Forests

The theory of TWCL’s sustainable management system is described in further detail in Section 4 of the TWCL Sustainable Management Overview Plan. Natural forests (old growth forests) are those unmodified forests that have not been modified by any form of human activity in the past, or by recent natural catastrophes such as major earthquakes. These forests comprise approximately 42 % of the sustainable management estate. A summary of the theory for managing these forests by following natural patterns is outlined below. Forest Canopy Gaps

When a tree dies, it can be from a variety of direct (wind or earthquake) or indirect causes (competitive suppression or pinhole borer attack after drought stress). Tree death is generally characterised by either the toppling of a tree (roots and all) or death in situ followed by steady rotting until the main stem weakens and fails, falling to the ground. In either case, the result is a small gap in the canopy of the surrounding forest, often enlarged to the extent to which neighbouring trees are also destroyed by the falling trunk. Over time decomposition of the woody material begins and the elevated sites created by woody debris and root plates provide good competition-free sites for further regeneration.

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A silvicultural selection system aligned to this process can lead to the creation of forest gaps of a size and temporal and geographic spacing that will fit well within the natural tolerances of the forest ecosystem. Forest Structure

Across the area of any natural all-aged forest, there is a range of trees from seedlings to giants, extending across all the diameter classes. In any given regenerated gap, mortality from desiccation, frost, competition, disease and damage is very high in the early years. Ultimately a small proportion of trees survive to become very large old trees while new ones grow up behind in adjacent sites. As these old trees die they too are replaced by the next oldest generation following behind.

By the removal of only a small proportion of the number of stems in any diameter class and by limiting removals in proportion to the naturally occurring frequency of stems in each diameter class, the general structure of a given forest type can be retained. In addition, the extent to which the proportions of the larger diameter classes are removed or left can be used to control the degree to which large old trees can be maintained as part of the forest ‘ecosystem’ structure. Maintaining Productivity

The key determinant for maintaining productivity under a selection system is that harvesting continues at low levels across the range of diameter classes, the ‘harvest zone’, where merchantable sized trees can be predicted to die from competition, old age or physical damage from death of adjacent stems. As stems die, immediate site growth potential is transferred to individual adjacent trees that get bigger. Competition nevertheless continues unabated across all the size classes, as does mortality. In the group tree selection system, this constant ‘ingrowth’ of new seedlings and their maturation into large trees under a totally natural process is harnessed to provide a sustainable harvest. This is achieved by ‘skimming off’ a small proportion of the live trees growing in the range of merchantable diameters (harvest zone) before they die naturally.

Mortality amongst juvenile seedlings is, like many normal biological populations, very high but rapidly declines amongst larger stronger stems. In the long run, growth and mortality are balanced and the forest standing biomass remains more or less stable. Once a small harvest is removed the balance alters. The removal of trees results in a partial ‘releasing’ from competition of some of the remaining growing trees. The forest responds with a compensatory decrease in mortality and an increase in growth and compensatory regeneration to the extent that in the long run, total turnover (gross increment), now comprising ‘increment’, ‘harvest’ and ‘mortality’, remains the same.

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The removal of some nutrients are an inherent component of any primary production system and are unavoidable where timber production is an objective of management. However under the proposed management system, rules have been specified to reduce such effects. The primary rule is that TWCL will adopt the practice of retaining all defective wood and branch material on site (even where this could be used in fuel or chip markets) to provide invertebrate habitat and to ameliorate the consequences of any nutrient drain. This will ensure that between 70 to 80% of all vegetative biomass is retained on site. In addition, the rules requiring small sized natural gaps serve to prevent temperature extremes and exposure leading to volatilisation or leaching of nutrients.

3.2.2 Production Thinning of Recovery Forests

Recovery forests are those forests that have been heavily modified by human activity in the past, or subject to a catastrophic natural event such as a large earthquake or windblow. These forests make up approximately 58 % of the sustainable management estate. Unlike old growth forests, recovery forests are characterised by semi even-aged to even-aged structures, and can not initially be managed effectively and sustainably by the same silvicultural practices as old growth forests.

Untended even-aged stands are unstable. After logging, beech regeneration was normally vigorous, leading to large stands of more or less even-aged regeneration. In a normal response, the beech seedlings would develop under intense competition over a period of 40 to 80 years into stands comprising tall, straight but very thin poles. Such stands are often grossly overstocked and, from experience, tend not to develop into good mature forest, but become severely degraded by pinhole borer, and collapse (Franklin, 1994).

Normally such stands could not have added to the productive forest base until they had naturally progressed through cycles of collapse to become more stable uneven or multi-aged forest stands. Alternatively newly regenerated stands subsequently subject to intensive silviculture would have been felled upon maturity as large coupes. This would lead to a continuous pattern of large even-aged stands and their associated requirements for relatively high impact management. It is difficult to define specific operational practices for recovery forests given that past history and current status will play the greatest role in determining appropriate silvicultural actions on a site by site basis. Generally, it can be expected that the older the recovered forest and the lighter the original logging disturbance (e.g. pit prop extraction), then the more management will be aligned to natural forest methods. Conversely, youthful stands and higher intensities of past intervention will lead to approaches as discussed below. However, broad management principles and safety measures and operational parameters such as restrictions on the percentage of the basal area (or volume) of stems which can be removed can be set.

The broad basis of the application of production thinning will be to successively thin down the existing even-aged stems to create, over long periods (50 – 100 years), a more stable, all-aged, age-class profile that becomes continuously productive, more ecologically diverse and can be incorporated into the total productive estate. This approach could also break the need for coupe or clear felling that would be perpetuated by continued even-aged management.

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Even within any even-aged stand there is, however, a range of tree diameter classes. An ability to successfully production thin these stands by removing larger stems when economic is a means of:
  • Preventing the cyclical collapse of such stands by reducing competition;
  • Increasing forest and site productivity by capitalising on the strong beech response to thinning and utilising trees that would be lost in the normal collapse cycles;
  • Providing a means of maintaining a more natural forest ecosystem by converting such stands over time to all and multi-aged stands; and
  • Avoiding the need to clearfell even-aged stands at maturity
Production thinning has not historically met with a lot of success in the past, with windthrow, over thinning, and, pinhole borer all taking their toll (Kirkland, 1965). However, with the advent of aerial harvesting, operational research utilising small helicopters has confirmed that this technique is now feasible in some stands (Dalley, 1996). In such examples, the ultra low impacts and extraction intensity possible with helicopters combined with basic forest hygiene management can result in successful completion with few adverse impacts on the remaining forest.

The system will be developed over time through operational research on selected sites. Research is needed to determine the regimes necessary for best production thinning results. With positive results from the trials to date, three years after harvest, and no adverse effects from what were considered to be high-risk threats of pinhole borer and windthrow, the main area for refinement will be to develop measures of response to varying levels of thinning. The resource consent will need to be sufficiently flexible to allow production thinning to occur in recovery forests, and to allow production thinning regimes to be developed. Production thinning must be considered in the context of the existing ecological values of these forests which are already highly modified.

Current research has focused on the application of a ‘thinning from above’ whereby the productive harvest is taken from a proportion of larger stems present in the stand. This system relies on the response of the retained co-dominant and to a lesser extent sub-dominant stems to releasing from competition and subsequent more rapid growth. The advantage is that a merchantable harvest is easily obtained while slowly converting the stand to multi-aged or all-aged status through the successive regeneration phases encouraged by the thinning. Stand biodiversity can still be enhanced by allowing some trees to grow on, eventually becoming large old trees.

Production thinning will not be standard practice exercised uniformly over large areas in the initial periods of sustainable management. It is an operational and silvicultural decision that must be made on the basis of an assessment of the condition of individual stands (groups) of trees at scales ranging from just a few to many hectares. The decision will be based on the health, density, time since logging and species and diameter distributions within each stand. However, the maximum removal shall not exceed 12% of standing volume above 20cm dbh or approximately 8% of the density of merchantable stems. Returns to the stand will be

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limited to no more than once per ten years other than for salvage purposes, and will not be visited for this form of management for more than five returns in order than stand genetic quality, form and vigour is not degraded.

Once stabilised and of a satisfactory diameter/age profile, or five harvest returns for production thinning have been undertaken, production thinned recovery forests will be integrated into the old growth forest management regime. When the decision to integrate a previously modified forest is finally made, it reflects the fact that the modified forest has reached an ecological status more comparable to “old growth” forest. As such it is not anticipated that there need be any controls or restrictions in the resource consent upon the managers ability to make that decision to shift to an old growth forest management regime. In general, the reverse situation does not apply, and a recovery forest management regime will not be able to be applied to old growth forests. However, it is likely that small areas within “old-growth” forest that have been subject to past catastrophic demise (eg windblow) will be identified from time to time and should be managed under a recovery regime. In cases where this occurs, the areas presence will be documented, mapped and recorded for verification under audit.

Forests designated as recovery forests at the present time are shown on the maps in Appendix 8, Volume 2. The remaining forests in the estate not in areas reserved from production are old growth forests. Further information on detailed forest composition types (which is relevant for detailed operations planning following the granting of consent) is included in Section 3.3 of each TWCL Sustainable Management Plan. At the commencement of consent, forests designated as old growth and recovery will be required to be managed by the appropriate management regime as outlined in this application. However, TWCL will be able to convert recovery forest management to an old growth management regime at any time at its discretion. Conversion of the management regime in the other direction (i.e. from old growth to recovery management) will only occur where uniform aged patches of forest resulting from past natural disturbance are identifiable on the ground and able to be mapped and recorded as distinct management units.

3.3 Yield Establishment

3.3.1 Yield Establishment Principles

The regulation of timber yield is a complex process based on the modelling of the forest resources in terms of their patterns of growth and death. Forest population patterns are often typified by a trend toward an abundance of small seedlings and a much reduced number of large trees. As with any population of natural plants or animals, the exact composition of the forest at any point in time is not static. New trees are constantly ‘born’, some grow on and mature though some die due to disease and ‘accident’ along the way. As groups of individuals mature and grow old, the proportion that have died increases until ultimately all the members of the original group have died, their presence on any one site being replaced by up and coming younger generations. In this way, the forest is replenished.

The shape of the forest age class distribution (structure) represents a snapshot of the demographics of the forest population at any one time and reflects:

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  1. RECRUITMENT: the number of seedlings that establish, survive and grow to become small trees of measurable size (the number of young being born and their survival rate);
  2. SURVIVOR GROWTH: the amount by which live trees above the minimum measurable limit increase in diameter and accumulate wood between measurement periods (maturation of young into full-grown adults);
  3. MORTALITY: the numbers of trees within measurable size classes that die through competition, disease or other external causes within a measurement period.
In forestry terms, the sum of 1 and 2 above plus any harvest are jointly referred to as “net forest increment” (or ‘net increment’). ‘Gross increment’, is a term for the total of recruitment, survivor growth, harvest and mortality (Davis & Johnson, 1987).

Growth processes follow a pattern of smoothed fluctuation about an average, while mortality tends to follow a pattern of minor fluctuation, punctuated by periodic large mortality events. Consequently, in the short to medium term on any particular site, net increment and mortality may not be in balance. Stem numbers and volumes may vary considerably from site to site within any one forest type.

However, over longer periods in a natural forest, forest increment equals mortality (Wardle, 1984). If it did not, either the number and size of trees would get larger and larger or the forest would slowly disappear. In forestry terms the sum of the net forest increment and mortality is called ‘gross forest increment’ (or ‘gross increment’) and represents the total turnover of biomass in the forest at which the forest structure could remain constant. The gross increment calculated on an annual or periodic basis represents the maximum theoretical capacity of the forest to produce a yield of timber though such yields would not be practically achievable or ecologically sustainable as all dead or dying trees would have to be salvaged and the forest density and structure would change significantly.

The yield of trees that may be theoretically harvested from a forest, while maintaining a near-natural forest structure and ecological function over the long term, (called the ‘sustainable yield) is equal to the forests net increment. The sustainable yield will always be significantly lower than the gross increment. The permissible harvest is that proportion of the net increment or sustainable yield permitted to be taken and in this application has been conservatively set at 50 % of the sustainable yield. In this proposal, permissible harvest has been calculated in relation to the net increment of trees of each commercial species greater than 30 cm dbh, to upper limits which have been set for each species for ecological reasons (e.g. retention of habitat for hole nesting birds).

To establish the amount of timber that can be safely removed from the forest over the long term without causing undesirable changes to forest structure and ecology, it is necessary to determine recruitment, growth rates and mortality for each relevant species and then adjust the increment for the proportion that:
  • is merchantable;
  • allows ecological constraints to be met;
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  • allows for margins of error in data and allows for major episodic natural disturbances; and
  • maintains the structure of the forest.
In so doing the silvicultural objectives will be met.

Computer models have been used for the purposes of assisting in the setting and regulation of permissible harvests based on the inputs discussed above. These models have been in use in the commercial production of rimu from the sustainably managed forests of Saltwater and Okarito.

A summary of silvicultural objectives is as follows:

Old Growth Forests
  • Maintenance of forest biodiversity and wildlife habitat;
  • To harvest a percentage of net increment proportionally across specified diameter classes so as to maintain, based on existing average conditions, a near-natural forest structure, composition of species and forest biomass;
  • To take care in all operations to at least maintain, if not improve, the productivity (in quality and quantity) and relative site capacity of the forest ecosystem.
Recovery Forests
  • To maintain landscape, soil and water values and improve wildlife habitat;
  • To harvest a percentage of the net increment across specified diameter classes so as to maintain a productive near-natural forest, with a diverse composition of species and forest structure while returning the stand to a more all-aged structure;
  • To return the forest biomass on the site to the levels comparable with similar unharvested forest types and to take the opportunity where appropriate, to improve forest timber quality and ecosystem productivity.
3.3.2 The Forest Yield Model Overview of the Model

The permissible harvest forecasts for individual beech species are derived using a deterministic growth model for uneven-aged forest similar to that developed by Usher (1966). The model and inputs are discussed in detail in sections 5.1.1 - 5.1.5 of the TWCL Sustainable Management Overview Plan (pp. 142 - 150).

The growth model uses a column vector to represent for each species the number of trees present per hectare in 10 cm diameter units. All trees greater than 100 cm diameter are

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grouped into a single maximum size-class. Tree sizes for beech species were derived from gross MARVL inventory data. The model assumes that trees in each diameter size-class are uniformly distributed through that specific class.

The data is derived for each species across the entire working circle, which includes several forests and forest types. This provides an average representation of forest structure that provides a global permissible harvest for the working circle.

The data can be subdivided for individual forest types and reinforced by more localised inventory for determination of annual compartmental yields where necessary. Over the felling cycle, additional inventory data will enable stratification of more specific forest type characteristics and stand specific yield calculations. Criticisms of the Model

The Royal Forest and Bird Protection Society recently commissioned a Landcare Research critique of TWCL’s modelling (Evaluation of model evidence for sustainability in Timberlands West Coast plans, Landcare Research Contract Report LC 9899, 1998). Their investigation involved reconstructing a growth model similar to TWCL’s using TWCL’s input data. Their primary conclusion was that the TWCL model has a hidden bias and as a result “the proposed scheme is unlikely to be sustainable”. The Landcare model projected a depletion, almost to extinction, of the total forest and importantly, larger older trees. TWCL believes these conclusions are totally unfounded. The management system proposed is designed to avoid such effects.

The extraordinarily pessimistic outcomes proposed by Landcare are a result of the structure and inputs to the model. TWCL also raised concerns related to the extreme length of time over which extrapolations were modelled. These were well outside the duration in which severe natural disturbances could be expected that would render such forecasts, whether for managed or unmanaged forest, essentially redundant. The Landcare model does not reflect the 35 year proposal which is the subject of these applications. Neither did such long-term fixed projections allow for corrective management interventions.

TWCL’s response to Landcare’s criticisms were as follows:
  • TWCL strongly disputed the critique's conclusion that the beech management plans were not sustainable. Their conclusion was based on an incomplete replication of the process TWCL followed, and represented an abstraction of the model from the controlling management system. The mathematical bias as reported in the critique report was not a significant error factor in the model used by TWCL though the highlighting of its potential was welcomed.
  • In reality the prediction of forest decline in the first critique report stemmed from retrieval of its own assumptions. The published (low) mortalities were adjusted upwards to achieve a stationary population, an additional harvest was imposed without compensatory growth or mortality, and recruitment rates remained equivalent to the average for undisturbed forest. Such a modelled projection must always decline. The conclusion that the forestry proposal is unsustainable was thus unfounded, as subsequently confirmed in updated

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            Landcare models that at least demonstrated that the yield if not the structure of the forest could be
  • The critique made unrealistic assumptions that no compensatory absorption of tree mortality, growth and regeneration would occur following timber extraction. There is ample evidence to show that tree growth under reduced competition (created by canopy tree removal) will increase (potentially it will more than double) from the rates used in the TWCL model. Similarly, regeneration triggered by gap formation is likely to greatly increase the number of recruits assumed. Mortality will also in part be light and density dependent and could be expected to reduce. Such responses would serve to ensure that the extreme effects postulated, would not occur.
  • TWCL applied a 50% "precautionary margin" to its proposed harvest calculation. The resultant allowable yields for all beech species of 2.6 m 3 per ha per year are approximately half those approved by MAF in other operating plans in managed beech forests.
  • TWCL recognises and accepts that its chosen model could not answer all questions to all people, few models can, particularly at an early stage. However, the model and data limitations were managed within a conservative set of starting assumptions, and integrated into an adaptive management framework. The plans specifically noted the need for regular review of both model systems and input data within an adaptive management framework that controlled risk.
TWCL’S plans specifically note that more complex ecologically based models will be developed as more monitoring data is available (in approximately 10 years time). Until then, there is little justification for developing more sophisticated models for which there are no reliable data for parameterisation. TWCL believes that the extraordinarily low rates of timber removal and all of the safety margins incorporated into its proposal will make imposed changes on the forests safe and minor. New Models

Since the publication of the first Landcare report in April 1999 the debate has progressed to further levels.

In the first instance, TWCL reviewed its model in respect of the issue of bias. The potential for mathematical bias is related to the distribution of stems within a size-class. TWCL assumed a uniform distribution where trees were evenly spread across a size class, whereas Landcare assumed an exponential distribution where the spread is sloping. The bias can be eliminated by the next level of sophistication to a model where every tree is individually projected forward by a growth function for a time period. This “tree list” model uses the actual distribution of trees in the size-class not an assumed one.

To benchmark its original yield forecast TWCL carried out projections using individual tree projections. The results provided confidence that the yields as published in the Management Plans are valid in terms of any effects of the suggested biases. Rather than being overestimated, yields are in fact more conservative than expected. This is because the tree distributions of the actual forest were neither uniform nor exponential as assumed by the

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respective parties. Furthermore TWCL had “rounded down” the tree numbers in each size class. This provided a further conservative margin.

Subsequently, Landcare undertook further work and produced an improved model that they then published on the Landcare website (July 1999). This model essentially built on the early version adding improvements such as density dependent growth and latterly mortality response. Both these adjustments served to reduce the extent of the pessimistic projections of their previous model. This led to a revised pronouncement from Landcare that the timber yields were sustainable but that there would be significant ecological trade-offs over the long term (50 –100 years).

However, TWCL believes that the projections of the Landcare model are erroneous because there remains a fundamentally incorrect assumption that every tree felled in a selection management regime adds to the natural levels of loss that prevail in these forests. This means the total losses of trees to the forest ecosystem are substantially higher in the managed forest than the natural forest. Such an assumption is true if the “selection” process used aims to select only healthy trees of good form. However this is not what selection forest management does. If it did, then the silvicultural management of forests that has been practised successfully for centuries in some forests in Europe, could not possibly work because just as Landcare’s model would predict, major losses of forest structure and function would occur. Clearly, this has not happened.

In understanding why such major differences arise between Landcare’s hypothesis (Diagram 1) and the expectations of TWCL, one needs to go back to the basis of the management system. A fundamental assumption underpinning the implementation of TWCL’s selection management system, is that mortality is subsumed into harvest through the careful selection for harvest of trees already prone to direct mortality or mortality by association with dying or falling trees. TWCL plans to harvest 50% of the potential mortality-prone trees and leave the remainder to die naturally in the interests of retaining natural processes and conservative yield uplift. TWCL therefore assumes that much of the harvest will be compensated for by a reduction in natural tree losses.

The key to the error in Landcare’s modelling lies in the following statement published in a recent submission by Landcare on the subject. “…the Timberlands West Coast model amounted to a belief that they could obtain a density-dependent response from the forest without reducing its density”. Clearly such responses cannot be anticipated other than on the basis of an expected response to the severe “driving-down” of forest basal area as modelled by Landcare.

What has been completely overlooked by Landcare and is the very essence of any selection management system is that harvested volume can be subsumed into total mortality. This is achieved because each felled group of trees is sited around a tree(s) that is selected due to its likelihood of death or collapse in the near future. When such trees die and / or fall naturally they invariably directly damage, destroy or induce pinhole attack in adjacent trees ( between 1 and 10 ) irrespective of the health of those adjacent trees at the time. Those trees also then become the dominant component of non-catastrophically induced natural mortality. By absorbing some of this natural mortality into the managed forest’s harvest and with

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minimisation of felling damage or pinhole attack to adjacent trees through good management technique the total mortality rate in the forest is not significantly altered. The magnitude of the potential of the error can be seen when comparing the scenarios illustrated in Diagram 1 and 2.

Diagram 1; The impact of the Landcare assumptions as projected by their model at a harvest rate equal to 50% of net increment.

Residual Stems Greater than 70cm
Stand Density m2 /ha
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Diagram.2; Projections using the Landcare model with adjustments to provide for Timberlands West Coast harvest rate and mortality pre-emption.

Residual Stems Greater than 70cm
Stand Density m2 /ha
The outputs above are a very different outcome to that forecast by Landcare. They reflect the results from a fully integrated sustainable forest management system as distinct from simply cutting down trees (the essence of the Landcare assumption).

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To be reliable over the longer term any modelling system requires very high quality biological data that is not available at the present time. Collecting such data involves intensive long-term inventory, monitoring and allied research studies to calibrate the constantly changing dynamics of a forest whether it is managed for production or reserved for conservation.

For this reason and in the face of limited information TWCL has used the Landcare model to test a number of sensitivities. It is in this mode of testing sensitivities rather than attempting to define absolutes, that the Landcare model provides some added benefit. TWCL conducted a range of sensitivity evaluations in relation to the degree to which mortality can be subsumed and other mitigating management strategies that could be implemented to protect a strong presence of large old trees.

As a result of these sensitivity tests TWCL remains confident that while any managed forest will change from one that is never managed (just as any forest managed or unmanaged, will change over time relative to its current condition), important structural and ecological functions within the forest can be maintained. The “tradeoffs” claimed by Landcare will not occur and in reality the changes in the managed forests should not be easily discernible to the general public. The original Landcare model outputs reflect an extreme end of the spectrum of sensitivity results that could arise. As such they are a useful tool for reminding managers of the important components of the management system that require care and monitoring within an adaptive management framework to ensure such adverse results do not eventuate.

In section 4.1 of the TWCL Sustainable Management Overview Plan, TWCL describes the nature of the desired management outcome which is to ensure that key facets of the managed forest in general remain within the bounds expected for regular short to medium period natural disturbances affecting unmanaged forests. The TWCL sensitivities tested in the Landcare model suggest that this goal is feasible. They suggest that the changes that do occur in the managed forest will be acceptable, will not impact significantly adversely upon key wildlife and will be well within the bounds of the expected occasional large natural events that will cause change from time to time. It should also be noted that the forest as modelled by Landcare will of its own right, with no periodic natural disturbance, and no harvesting, still suffer losses of up to 7% of large old trees (cf the present status) or 12% from maximum numbers, for long periods of time. Furthermore, over the period of this consent (35 years) even the worst case assumptions of the Landcare model show minimal net effect in that large old trees will still exist in managed areas at high levels compared to the present status.

Section 4.4.6 Environmental Implications in the Sustainable Management Overview Plan describes some of the expected forest changes that might occur from the introduction of a harvesting regime. Units of Yield

In normal forest operations, wood yield is determined on the basis of volume measured in cubic metres (m3). While appropriate in terms of management of woodflows and costs from the forest gate, establishment and monitoring of forest yield in these terms can pose difficulties. Consistency in measurement of the productive volume of a tree at any point in time depends upon consistency in the specifications of what constitutes a marketable product. These can change over time.

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In the case of the natural forests, the maintenance of structure and productivity is achieved by retaining numbers of trees of specified average diameter over the full range of diameter classes. TWCL’s management plans are written on the basis of determining yield in terms of tree numbers from specified diameter classes. Not only does this ensure greater transparency in the management of the harvest yields and their impacts upon the forest structure, but it also makes recovered volume and changing market specifications independent of the biological yield. Over any short period of time, marketable volumes will have a high and close correlation to numbers of trees of given diameter. But in the long term, markets and marketable volume definitions may change and thus so to may the relationship between volume and tree numbers. Irrespective of such change, the biological consequences of a yield of a number of trees of given diameter over a specified range of diameter classes will be constant.

For these reasons, yield in these plans will be specified in tree numbers and converted to merchantable volume of the day for commercial management purposes. Yield Precautionary Margin

A number of factors can contribute to errors in the planning and establishment of the sustainable harvest. Not least of these is the large natural variation that can occur in forest structure and biomass from time to time following major disturbance. For instance the total forest, rather than just parts of it, may not be at its long run average status. This could mean that the periodic growth at a given point may be above or below the norm. Reliable measures of growth will only be achieved over time from the PSP (Permanent Sample Plot) system. Other influencing matters, such as the precision of data to specific sites, can also only be gathered over time.

Furthermore, with an extensive low intervention harvesting system as prescribed in these plans, the recovery of a significant proportion of mortality will not normally be achievable. Only in ‘visible’, more extreme disturbance events will recovery of high proportions of mortality be more likely and a management priority. In many other management systems high levels of silvicultural intervention and harvest mean a larger proportion of prospective mortality can be either recovered or prevented. However the balance of harvest removed from live growing trees is also greater and will lead to greater change to forest structure and age.

To ensure that such factors are accommodated, and in recognition that much of the potential net increment could not be effectively recovered through pre-emption of mortality or salvage of recently dead trees, a precautionary margin has been allowed. This margin is provided for in that the permissible sustainable harvest is set at 50% of the net growth increment. This level will not be exceeded unless a variation of consent is obtained in the future on the basis of research that determines that a higher percentage level of harvest is sustainable (and if the Councils or the Environment Court accepts that variation). In this particular case consent conditions will need to expressly provide for a capability to seek a variation for this purpose.

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37 Yield Adjustment

Within each 15 year cycle, complete re-measurement of the permanent sample plot system as well as other data collected over the period will be used to update the growth model projections. The results of this monitoring will enable measured levels of growth, mortality and forest status to be input into forest models to adjust permissible yields as required to achieve the defined management objectives.

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4.1 Overview

The previous section described some of the theoretical concepts behind the TWCL sustainable management system. This section describes in more detail how TWCL will actually apply these principles to its operations within the application area.

4.2 Permissible Harvest

4.2.1 The ‘Selection Harvest’

As discussed above, approximately 42 % of the sustainable management estate is old growth forests which have not been extensively modified by recent natural events or human intervention (e.g. logging). The total permissible harvest in these forests is set at 50% of the growth for the diameter classes from 30 cm dbh up to the upper diameter limit set for each species for ecological reasons. This level of harvest will generally amount to about 10% of the stems in those diameter classes over a 15 year ‘cutting cycle’ period. The cutting cycle period for old growth forests will be no longer than 15 years (Averaged over time this equates to one tree per hectare per year for 35 years).

The proportion harvested will be reviewed regularly as measured increment and mortality rates become available. The actual volume or number of stems to be harvested cannot be specified as part of the resource consent as it will vary with the return period chosen, the actual forest composition of the operational compartments harvested in any year and the continual change of the natural forest system which would occur regardless of management (see Section 4.2.4 of this document). However, on average about 15 trees will be taken from each hectare once every 15 years. A list of specific control measures for old growth forest harvesting is included in Section 8.2.3 of this document.

Within the permissible harvest there will be a number of trees across the diameter range that are of no commercial value. Felling of these trees in most circumstances is a requirement to maintain the inherent timber quality of the natural forest over the long term. To fail to take these trees may over long periods of time move the forests structure toward an overly senescent, highly defective status that becomes more prone to storm and insect/disease attack. Such non commercial trees as are felled will be left on the forest floor to maintain invertebrate habitat, as seedling establishment sites and to and avoid nutrient drain.

In recovery forests, the permissible harvest will be 12 % of the basal area of all trees >20 cm dbh up to the maximum dbh set for each species for ecological reasons. Once an acceptable age structure is established, or there have been five returns to an area for harvest, management will convert to that undertaken for old growth forests as outlined above. This conversion will represent an attainment of a ecological status similar to old growth forest. The minimum return felling cycle for forests under a recovery forest management regime is 10 years. A list of specific control measures for recovery forest harvesting is included in Section 8.3.3 of this document.

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4.2.2 Salvage Harvest

The recovery of salvage (i.e. trees which have fallen due to natural processes such as windthrow) will be a priority over selection harvest where readily identifiable. Salvage harvest will be included within the permissible harvest of 50% of growth, and is not additional to it.

In most years it is expected that salvage harvest will comprise only a small proportion of total permitted harvest, probably not exceeding 10%. However on occasions where significant disturbances have occurred, the total permitted annual harvest could be from salvage harvest.

4.2.3 Silvicultural ‘Improvement Fellings’

The TWCL Sustainable Management Overview Plan and working circle Sustainable Management Plans discuss “Improvement Fellings”. Improvement felling involves felling to waste a percentage of the defective gross increment (turnover) of immature stem classes. Estimation of total turnover is based on inventory data. It involves determining, through modelling, the number of immature stems of each size class that are ‘surplus’ to those required to maintain the existing number and size range of stems present in the stand as a whole. Improvement felling was proposed at a maximum of 10% of the surplus defective immature stems across specified size classes.

Many submissions to the Ministry of Agriculture and Forestry as part of the Government “approval” process of TWCL’s plans articulated concerns over the proposal to undertake improvement fellings in old growth forests. As a consequence, TWCL has decided not to undertake improvement fellings in old growth forests, and this activity does not form part of this resource consent application.

4.2.4 The Permissible Harvest

The permissible harvest that may be taken represents the integration of all the previously discussed constraints.

The natural forest is a dynamic system, and the structure and size class distribution within each working circle will continue to modify over time whether management occurs or not. Given this, it is not appropriate or practicable to place set limits on the actual number of stems for each species in each diameter class which may be removed. The most practicable restriction for old growth forests is 50 % of net increment in the harvest zone, which will be continually modified as the forest inventory is updated and new data input to the model. Setting rigid restrictions on stem numbers would result in inflexible management which would not allow TWCL to continually review the permissible harvest to ensure selection harvest is maintained within 50 % of growth. For example, if the natural forest system is in decline, it may in time become appropriate to reduce the numbers of stems in all or some diameter classes from that predicted to be appropriate at the time of start up. Independent audit procedures will ensure TWCL operations remain within acceptable levels of harvest.

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A percentage of basal area is the only practicable restriction on recovery forests, as these forests are all in various stages of recovery and the management of each area will differ depending on site by site characteristics of these forests. In time, they will be integrated into old growth forest management.

Examples of likely harvests from each working circle over the next ten to fifteen years, based on current input data, are included in Section 5 of each TWCL Sustainable Management Plan. However, these figures can be expected to change slightly either up or down from time to time following the five yearly external audits. These adjustments will be made to ensure yields remain within the 50 % of net growth increment parameter.

4.3 Harvest Regulation

4.3.1 Felling Cycle

The proposed felling cycle for old growth forests is generally nominated to be 15 years. This means that once a group of operational compartments jointly comprising approximately one fifteenth of the working circle area has been harvested to the permissible yield, (whether the yield is taken over one year or several), those compartments will not be revisited for further harvest for 15 years. The modelling and derivation of the permissible harvest is based on this premise. In practise it would not be economic to extract stems annually at the low rates per hectare set across the total estate. Therefore, 15 years of expected mortality is harvested from an operational compartment or group of compartments in a single operation, and the site is then not visited for another 15 years. While 15 years is the anticipated norm for a felling cycle, flexibility should exist to enable the felling cycle to be tailored to the geographic and ecological requirements of any specific area. The range over which such flexibility is required does not extend beyond a 15 year (maximum felling cycle), noting that the shorter the return period the lower the localised intensity of disturbance at the time of harvest but the more frequent the visitations.

For recovery forests, the return period is 10 years, with no more than five returns being permitted before these forests are integrated into old growth forest management prescriptions.

4.3.2 Forest Compartments

The old growth forests are divided into unit areas known as forest compartments. Compartments are delineated using significant features such as creeks and roads and significant ridges for boundaries. The compartments are generally established so that the normal range of forest variation due to site, aspect and landform are represented within the boundary. A geographically separate series of compartments will normally provide the annual yield. By utilising several smaller compartments to provide each annual permissible yield, it is possible to ensure that the average forest statistics from the amalgam of compartments are similar to the average for the forest utilised by the growth and yield model.

There are no compartments defined for recovery forests because operational activities, when commenced, will be confined to a “stand” (groups of similar status trees) level based on site

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by site evaluation. Yield regulation is based on fixed maximum rules and does not require compartment averaging. The locations of forests designated as recovery forests at the time of start up are shown on maps in Appendix 8, Volume 2.

TWCL will prepare operations plans that will detail the forest types within each compartment, and the associated resource data. Annual operation areas (groups of compartments) will have an individual harvest calculated based on their area and associated forest types where the compartment data varies significantly from the forest average. When the permissible harvest has been extracted from a compartment, it will not be visited again during the felling cycle period.

4.3.3 Harvest Regulation and Control

The actual yield harvested will be monitored against the permissible levels by maintaining records of tree numbers by species, location and by diameter class. The collection of this data will enable direct comparisons to be made with the modelled projections relevant to the forest types being harvested. Reconciliation will include longer-term matching with overall forest and type projections and short-term monitoring at the operational compartment level. The stump of each tree removed will also be tagged with an individual number and, where attainable, Global Positioning Satellite (GPS) co-ordinates obtained. This will enable full future audit by documenting all trees felled and produce sold. It will also enable audit of the yield at the operational/ compartment level as well as providing a means of checking spatial distribution of harvest.

For commercial reasons, the volume of timber derived from all logs will be recorded to maintain data on the quality and merchantability ratios of the selection harvest. This data will also be monitored against inventory predictions and marking tallies.

Regular independent audits of TWCL operations will ensure that operations remain within the above parameters.

4.4 Method of Harvest

4.4.1 Forest Harvest Management

The act of harvesting trees is the single most important silvicultural tool available to the forest manager under these passive selection management systems. Failure to observe the prescriptions set in the sustainable management plans could lead to outcomes from the forest that are at variance to stated objectives. It is the role of the forestry professionals to take account of a range of ecological and site criteria in their marking decisions to fully implement the principles of the management prescriptions. At the same time, where appropriate, they must provide the operational control that will prevent degrading of the current forest potential.

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The effects of harvesting operations can be controlled by attention to:
  • Professional tree selection;
  • Careful felling;
  • Log extraction; and
  • Forest hygiene.
4.4.2 Training for Indigenous Selection Management

TWCL has developed a solid skills base through its podocarp management and is determined to achieve the same with beech management. Indigenous tree selection, management and forest ecology modules meeting New Zealand Qualifications Authority standards are already being developed through FIT (Forest Industries Training). Module holders will be able to communicate and demonstrate a practical understanding of beech management. Those responsible for forest marking will normally be professionally trained in forestry or similar areas, and will have undergone additional specific peer training.

All personnel directly involved in beech management will ultimately be required to hold these qualifications or a suitable equivalent, or be undergoing relevant training towards obtaining these modules when they are finally adopted. Assessment of the competence of individuals will be conducted on an independent basis. There will be a program of regular bench marking and training to ensure consistent, high standards are maintained.

4.4.3 Canopy Gaps

Trees will be felled in groups between 1 and 10 trees to maintain canopy gaps of a size similar to those occurring naturally from non catastrophic disturbances. The maximum gap size permitted will be 0.05 ha although actual sizes will vary to account for the demands of shade tolerant and light demanding species and other site limitations (but will not exceed 0.05 ha). Gap location will be guided by the scale, pattern and shape of tree cohorts determined by past natural events, landform and the forest types present in the operation areas. Locations will be recorded by GPS using satellite fixes where possible, which will enable gap distribution to be monitored. TWCL will be responsible for ensuring global permissible harvest rates for each species and diameter class are not exceeded, and the keeping of records will enable this to be monitored by independent auditors.

The normal or average distance between forest gaps (edge to edge) will be 30m to 50m. The minimum permitted distance between gaps will be 25m.

Harvesting will normally result in 3 to 5 gaps/hectare in old growth forests within the felling cycle, and 30 - 50 trees/hectare at the most once every 10 years for recovery forests. By the time of the next felling operation in any given hectare, there will have been up to 15 years of growth in the original harvested areas and those gaps will be well regenerated and smaller ones completely closed over.

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4.4.4 Tree Felling

After marking the trees, the manner and care taken in the way they are felled governs the success of the whole management system.

Marked trees will be felled in a professional manner using directional felling techniques to minimise damage to adjacent canopy and understorey vegetation that is intended for retention. If a tree marked for felling cannot be safely or successfully felled then it may be left but will be removed from the schedule of trees for harvest.

If an adjacent tree is damaged during the felling process, it will also be felled to minimise risk of pinhole borer attack and be substituted for another live tree as part of the permissible yield.

4.4.5 Harvest Extraction

All harvesting, except within road lines where roads are extended or landings constructed, will be done using aerial methods (a heavy-lift helicopter to lift complete logs or a medium-lift helicopter to lift prepared logs or flitches).

The company’s experience over the past five years has demonstrated that helicopter logging is the most efficient and least damaging logging method for removing timber from indigenous forests. Helicopter harvesting currently has an economic operating radius of 2 km from forest skid sites resulting in fewer roads (which provide vehicle access to skid sites) and less impact on the forest environment than with conventional harvesting systems.

Because it has such a high daily production rate the helicopter spends very little time within the forest so that the noise and disruption to the forest environment is limited to approximately three to five days per compartment per year.

All logs are prepared to weight/ payload specifications before lifting and a suitable grapple point indicated on the logs by the treefeller. Marking of the point assists both log location from the air and is designed to assist a smooth and predictable lift from the forest. This reduces risks of canopy damage from swinging logs. Logs will be lifted directly clear of the canopy before horizontal movement commences.

Experience has shown that in some circumstances on steep slopes over 30°, with shallow soils, after prolonged wet periods and in still air conditions, helicopter rotor wash can cause individual stems to fall. Operations will be temporarily diverted or halted or only continue with a longer ‘long-line’ or in conditions of light to moderate winds if such circumstances arise.

All logs are prepared to weight/ payload specifications before lifting and a suitable grapple point indicated on the logs by the treefeller. Marking of the point assists both log location from the air and is designed to assist a smooth and predictable lift from the forest. This reduces risks of canopy damage from swinging logs. Logs will be lifted directly clear of the canopy before horizontal movement commences.

Experience has shown that in some circumstances on steep slopes over 30°, with shallow soils, after prolonged wet periods and in still air conditions, helicopter rotor wash can cause individual stems to fall. Operations will be temporarily diverted or halted or only continue with a longer ‘long-line’ or in conditions of light to moderate winds if such circumstances arise.

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44 Hygiene Measures

Pinhole borer has traditionally been viewed as the greatest single hurdle to effective beech management for timber. This issue is discussed in more detail in the Assessment of Environmental Effects section. However, in short, pinhole borer attack of trees in forest gaps (caused by natural causes or human intervention) can cause a decline in forest health. Traditional beech management sought to control pinhole borer by systematic removal of all suitable brood material from the site. This led to the concept of beech chipping. However, it is ecologically undesirable to remove non-commercial woody material, since this ‘coarse woody debris’ is important for nutrient recycling, the provision of invertebrate habitat and the provision of elevated competition-free seed regeneration sites.

If harvest management does not prescribe for the removal of brood material, or if harvest intensities are too high, then there is a risk that forest health and timber quality will be cumulatively downgraded. To avoid this potential risk, a number of forest hygiene procedures are proposed.

Site treatment will consist of either cutting up residual and non-merchantable material into short sections, depending on girth and internal composition, or making a longitudinal groove and applying 20 grams of urea. Further details of treatment for logs of various diameter sizes is included in Table 20 (p. 119) of the TWCL Sustainable Management Overview Plan. All stumps at harvest sites will also undergo treatment consisting of stump boring, applying 20 grams of urea, and filling the cuts with organic duff gathered from the surrounding area to provide inoculum for fungal invasion.

4.5 Forest Roading

4.5.1 Roading Network

TWCL already has a network of forest roads within the sustainable management estate, many of which have been established for past logging operations. The optimal working radius for lift helicopters is approximately 2 km from skid/ landing sites, and some extensions to the roading network will be required to allow operations within these parameters. Skid/ landing sites will be periodically established along the roads to allow the logs to be set down and loaded onto trucks for transportation from the forests. A summary of the extent of proposed roads and landing sites is as follows:

Maruia Working Circle Forests (within Tasman District)

Upgrade approximately 11 km of existing road, construct approximately 19 km of new road, and construct 17 new helicopter landings.

Maruia Working Circle Forests (within Buller District)

Construct approximately 8 km of new road, upgrade 7 helicopter landings, and construct 5 new helicopter landings.

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Grey Valley Working Circle Forests (within Buller District)

Upgrade of approximately 14.5 km of existing road, construct approximately 8.6 km of new road, upgrade 7 helicopter landings, and construct 12 new landings.

Inangahua Working Circle Forests

Upgrade of approximately 28 km of existing road, construct approximately 20 km of new road, upgrade 10 helicopter landings and construct 29 new landings.

Adjacent Land

Overall, about 30% of new roading does not involve clearance of forest but gains access to Timberlands’ forest boundaries through adjacent land. A significant proportion of the roads and landing sites described above are located on adjacent private land or within unformed legal road, adjacent to TWCL forests.

This consent does not seek approval for any road metal borrow sources which will be undertaken under existing consents, or new consents sought on a case by case basis as required.

Maps showing the general location of existing and proposed roads and landing sites are included in Appendix 1, Volume 2.

4.5.2 Road Construction

The maximum extent of new roads and landing sites will be in general accordance with the indicative proposed road and landing site network described above. However, exact road and stream crossing locations are not able to be defined until detailed harvest planning and engineering design can be carried out. Rather than apply on a road by road basis, a “black box” approach has been adopted for the road network, with design parameters being set to allow potential effects to be mitigated to an acceptable level. Any works exceeding these proposed consent conditions will not be covered by this resource consent, and separate consents will need to be sought on a case by case basis

Construction Standards

Road and stream crossing construction will be undertaken in accordance with generic construction operational standards sourced from the TWCL Environmental Manual -Standards Eight and Nine (see Appendix 4, Volume 2 of this document). These standards cover general construction standards, erosion control, runoff and water control, culverts and bridge design and decommissioning (culverts, bridges and fords only).

In addition to the general construction standards in the TWCL Environmental Manual, additional design parameters have been set to protect riparian margins of streams and ensure roads are located to avoid major side cuts. These parameters are:
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Riparian Zones

No clearing of vegetation for new roads or landing areas to be undertaken within 10 m either side of a medium priority stream, or 20 m either side of a high priority stream (stream classification criteria are included in Appendix 5, Volume 2). Road approaches to stream crossings will be excluded from this restriction within 50 m of a stream crossing point.

No felling of trees into or across streams.

No accumulation of slash or disturbed soil within any stream or streamside protection zone (i.e. within 10 m of medium priority stream or 20 m of high priority stream).

Areas Reserved from Production

New roads and landings will not be constructed in any areas reserved from production shown on the maps in Appendix 6, Volume 2.

Maximum Road Gradient

8° (the equivalent of 1:7 or 18% gradient) over any continuous 100 m section.

Maximum Batter Height

3.0 m over any 100 m continuous section.

Maximum Roadway Width (Cleared Road Corridor)

10 metres

4.5.3 Road Access

The total number of existing and proposed new vehicle accesses to and from TWCL forests to public roads is 50. The location of these accesses is shown on the maps in Appendix 9, Volume 2. Accesses generally involve an extension to an existing metal local road, or an intersection with an existing local road or state highway. All accesses will be upgraded or formed to the requirements of the relevant road controlling authority.

A summary of the number of accesses to public roads to serve each TWCL forest is as follows:

Buller District

Station Creek (Buller) 1
Camp Creek 3
Perserverance 1
Waitahu 5
McConnochie Creek 1
Antonois 3
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Blackwater 7
Orikaka 1
Heaphy 3
Larrys 4
Burkes Creek 2
Maimai 6
Mirfins 1

Tasman District

Glengarry 2
Shenandoah 3
Pea Soup 1
Station Crk (Tasman) 6


The access plans indicate where private logging roads will access public roads, as well as situations where landing/ skid sites are adjacent to the road reserve and no formal road requires construction. The application does not include access to strategic routes, other than in compliance with rule 7.4 of the Buller District Plan. Separate consents will be sought for any access that does not comply with the standards in that rule. At this stage those details have not been finalised.

4.6 Areas Reserved from Production

4.6.1 Streamside Management Zones

TWCL have allocated a priority rating to streams within its estate in terms of their relative importance to the maintenance of water quality and aquatic habitat and sensitivity. Riparian Management Zones have been established for medium and high priority streams of 10 m and 20 m respectively within which tree extraction is either not permitted, or is limited to single tree extraction in specified margins. TWCL’s classification criteria for low, medium and high priority streams is included in Appendix 5, Volume 2. The exception to this is where new roads cross streams, in which case extraction will be required within the immediate vicinity of the crossing.

4.6.2 Recreation Zones

The sustainable management estate as a whole has value for recreation. However, a number of areas with particularly high recreation value have been identified. Specific recreation zones have been identified within the various working circles to protect vegetation along important roads and walking tracks. Specific areas which affect the application area include:
  • a 250 m wide visual buffer strip along 12 km of the Waitahu River Road extending upstream from Gannons Bridge;
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  • protection around an important feature in Te Wharau Forest, where the Reefton -Inangahua Highway runs adjacent to the Rosemount Block;
  • 20 m buffer strips are also established along Blackwater Forest roads in the Grey Working Circle which provide access to the townships of Waiuta and Blackwater. This includes the Blackwater Road from SH 7 to Waiuta, and Snowy River Road, where these roads pass through or are adjacent to Blackwater Forest; and
  • a buffer strip against the popular fishing accessway in Te Wharau forest adjacent to the Rough River.
These areas are shown on the maps in Appendix 6, Volume 2.

In addition, special care will be taken adjacent to all forest roads and walking tracks to avoid felling trees over these roads/ tracks.

4.6.3 Wildlife and Special Forest Associations

The North Westland beech forests contain areas of significant indigenous vegetation, and significant habitat for indigenous fauna. The areas with the highest of these values were included in the conservation estate as part of the West Coast Forests Accord process. Notwithstanding this, a number of additional areas within the sustainable management estate have been identified as having particularly high value. Although in some cases it may be debatable whether these are significant for the purposes of the RMA, these areas will nevertheless be reserved from production. These areas are:
  • The valley floor of a major stream in the Blackwater Forest containing dense lowland red silver beech and some podocarps.
  • A small area of the Antonois forest has been reserved due to high S.I. Robin numbers.
  • An area of heavily modified recovering forest linked to virgin lowland beech forest comprising the Te Wharau forest that may have a presence of S.I. Kokako.
  • An area of dense mixed virgin beech and podocarp forest in the Larry's Creek Forest containing high numbers and diversity of bird species.
  • An area encompassing the limestone bluffs and earthquake faulted country in the Ohikanui/ Northern Te Wharau Forests which exhibited high species diversity.
  • The Glenroy Terrace area is recognised as having exceptional wildlife habitat. South Island kokako may be present along with notable concentrations of S.I. kakas and parakeets.
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  • A diverse and dissected forest amongst bluff systems or terrace landforms and inclusive of a wetland area have been reserved in the Maruia Forest. This area has been reserved due to high and diverse bird presence as well as landscape reasons.
  • Tilted limestone formations in Shenandoah Forest partly visible from the state highway that includes Lake Calsani and Cliff Creek Lake. The area has blue ducks in nearby streams, a black shag colony, and other water fowl present as well as many Robins in the surrounding forests.

The above areas are shown on maps in Appendix 6, Volume 2.

4.6.4 Special Landscape Zones

Magnificent limestone formations in Station Creek Forest are reserved from production,.part of a sequence from the Devils Knob south to the Upper Rappahannock River. These spectacular uplifted bluff systems have important landscape and wildlife values.

Several isolated ridge tops throughout the central area of Station Creek Forest are reserved from production. These sites are exposed and disturbance of any trees poses a high risk to the stability of the forest.

The above areas are shown on maps in Appendix in Appendix 6, Volume 2. The proposal will not affect any other “outstanding” landscapes or natural features.

4.7 Site Servicing, Structures and Signs

4.7.1 Potable Water

Potable water will be transported into the site by operational crews. No potable water supply from ground or surface water will be established.

4.7.2 Sewage Disposal

Due to the relatively remote location of operational areas, no toilet facilities will be constructed. Human faeces will be buried on site.

4.7.3 Refuse Disposal

All refuse will be collected and transported from operational areas for disposal in an appropriate landfill site.

4.7.4 On-Site Car Parking

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Two to three vehicles will be parked at a skid site at a time during felling operations, which may be increased by two to three additional vehicles during extraction. Vehicles may include utility vehicles to transport staff, and during extraction operations a loading vehicle, tanker (for helicopter fuelling) and any logging truck being loaded. There will be no requirement for any vehicles associated with forestry operations to park on any adjoining land (other than on constructed log landings) or public roads.

4.7.5 Buildings and Structures

No buildings and structures (excluding signs) are required and none will be constructed in association with this proposal.

4.7.6 Signs

Temporary signs will be erected on forest roads during logging operations for public safety reasons. The signs will only be erected on roads affected by operations, and will be removed once operations in those areas cease.

Other signs at forest entrances will be erected to inform the public of access issues, kiwi protection requirements, etc.

4.8 Storage and Use of Hazardous Substances

There will be no permanent storage of any hazardous substances within the sustainable management estate. Substances required on a temporary basis in association with forest operations are as follows:
  • aviation spirit will be tankered into skid sites as required.
  • 10 litre tins of petrol and oil for chainsaws will be carried in by foot or by helicopter to areas being felled.
  • Bags of urea up to 50 kg in size will be temporarily stored at skid sites within operational areas being harvested, and smaller quantities in the order of 5 kg will be carried into actual tree felling sites for stump treatment.
  • chemicals for pest control will be brought into the site on an "as required basis" but will not be stored within the forest outside pest control operations.
Temporary storage of hazardous substances and fuelling of any vehicles will not be permitted within 20 m of any waterway.

4.9 Intensity of Operation

Harvesting operations will potentially occur somewhere within the sustainable management estate 365 days a year during daylight hours. Helicopter operations would typically occur for two to three days in an operational compartment per felling cycle (i.e. once every ten to fifteen years for old growth forests). Chainsaw use will occur more frequently within the estate and may be undertaken on any day during daylight hours within operational compartments being harvested. In any operational compartment felling operations would precede aerial lifting (1 –

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3 months), and cease after the completion of operations until the next cycle in 10 – 15 years time. However, areas being felled will be continuously moved around so each gap or stand of trees will only be subject to harvesting operations for a short period once only during the felling cycle period.

4.10 Vehicle Movements

As the proposal is a passive management system, most vehicle movements will generally occur from accesses during harvesting operations. These movements will only be temporary and for relatively short periods of time. For the purposes of this application, a vehicle movement refers to a single entry or exit movement to the site. Therefore, a vehicle entering and exiting the site constitutes two vehicle movements.

As described above, three working circle areas fall within the application area, which includes the full Maruia and Inangahua Working Circles, and part of the Grey Working Circles. From any one of these working circles, the volume of timber extracted is expected to be within the range of 12,000 m 3 to 20,000 m 3 in any year (in the Grey Working Circle, none or all of the quantity may be from within Buller District an any one year). Up to six operational compartments per working circle per year may be harvested. For felling operations, this would involve 6 - 12 employees per working circle, and 2 - 4 associated light vehicle movements per day. In addition, up to two employees and two vehicle movements per day would occur across each working circle throughout the year for general forest management. Aerial extraction would occur up to a maximum of six times per year per working circle. This activity would involve up to ten people with 4 - 6 associated light vehicle movements a day during each extraction operation, which would last for a maximum duration of seven working days, although more typically 2 - 3 days duration.

Log transport from the site would occur concurrently with helicopter extraction operations, up to a maximum of six times per year per working circle. Each extraction event would see approximately 2,000 tonnes of timber removed from each working circle, which equates to approximately 70 truck loads per event (28 tonnes per truck). It is estimated that 7 - 10 truck loads a day would be removed per extraction event, resulting in log removal operations lasting for 7 - 10 days per event. A log loader would also be involved in these operations, but would typically be involved in only two movements to and from any public roads per extraction event. Total annual truck loads for each working circle would therefore be a maximum of 420 per annum (840 movements) being spread diffusely among the many accesses serving each working circle.

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