Multi-Objective Forest Landscape Projection Modelling-Problems and Prospects

Abstract

To be able to make the right decisions in forestry today, the long-term effect of these decisions has to be considered. Multi-objective forest landscape projection models are tools that can be used to illustrate the effect of different management alternatives in a landscape. An integrated approach facilitates multi-objective considerations and decisions. A number of modelling systems has been developed. A modelling system contains numerous sub-models, each one modelling a particular part of the forest ecosystem, the socio-economy or other aspects of interest. Models and data are intimately connected, and different methods for collecting data and their relevance for different models are examined. The sub-models interact with each other in such a way that the dynamics of a forest is simulated.

This article examines different sub-models for tree growth, economy, biodiversity, forest recreation and soil, and various uses for multi-objective forest landscape projection models are suggested and some examples are presented. Almost every model is associated with variation, uncertainty, and underlying assumptions. Errors in data and models, their origin and propagation through models, are discussed. The future development of forest models and their employment in planning and decision making are considered.     

Defining the forest landowner’s utility–loss compensative subsidy level for a biodiversity object

New, cost efficient and voluntary biodiversity protection tools may require bidding price definition on part of the seller. Both the seller and the buyer can withdraw from negotiations if they find that the conditions of the protection contract are unacceptable. However, it can be very difficult for non-industrial, private landowners to define the bidding price demand for their biodiversity objects. The terms of the protection contract, the production possibilities of the forest holding, the forest owner’s multiple forest management goals and their substitutability, and the possible monetary subsidy paid for biodiversity protection should all be simultaneously taken into account when estimating the owner’s price demand for protecting the biodiversity object. This study strives to provide relief in resolving this problem by presenting an approach in which the landowner’s utility–loss compensative subsidy can be defined based on the owner’s forest-holding level utility function and the production possibilities of the holding. The properties of the approach are illustrated by four planning cases in which the length of the protection period (permanent or 20-year temporary protection) and the holding-level goals were varied. The utility functions of the cases were derived by selecting numeric goal variables for the goals, and by defining weights and sub-utility functions for these variables. Varying subsidies for protecting an old-growth spruce stand were included into the simulation of “No treatment” schedules for the examined stand, and the holding-level total utility was maximized for every price level. The utility–loss compensative subsidy was found when the holding-level total utility equaled the total utility achieved in the plan where the stand was regenerated. This subsidy, however, is not necessarily the exact price that the owner should ask from the buyer; all prices above the defined subsidy level will increase owner’s utility if the buyer accepts them. It was concluded that the presented approach provided consistent results in the four cases and that it thus offers valuable decision support for current biodiversity-protection programs.     

Effects of administrative land-use and technical land-form constraints on timber production at the landscape level

Abstract

This study quantified, across a landscape in Eastern Finland, the influence of administrative land-use and technical land-form constraints on timber production. Spatially explicit data about the nature conservation areas, land use plans and steep slopes were integrated with Multi-source National Forest Inventory (MS-NFI) data. The Finnish forestry model MELA was used in the calculations related to updating forest data and estimating different scenarios of timber production with and without constraints. In the study area, the annual volume of maximum sustainable cutting removal defined for the next 30 years was decreased by one-third due to restrictions. The presented approach could be used, for example, to assess timber availability at the landscape level. Future challenges include ensuring the compatibility of spatially explicit data obtained from different sources, identifying the feasibility of forest management operations in the restricted area, and incorporating near-nature forest management operations in the forest planning system in order to estimate the timber production.     

Key structural forest connectors can be identified by combining landscape spatial pattern and network analyses

Conservation and enhancement of ecological connectivity is widely recognized as one of the key objectives of forest landscape management. However, practical difficulties still exist due to the lack of pragmatic and operational methodologies that can be efficiently applied for these purposes within the scope of a forest management plan. Here we present the novel integration of two recent approaches for analyzing forest structural connectivity that offers considerable synergies and potential relevant benefits for forest planning at a variety of scales. We combine the morphological analysis of forest spatial patterns with recent indices for the analysis of landscape network connectivity based on the concept of measuring habitat availability (reachability) at the landscape scale. The combination of these approaches in a single integrated workflow embraces from (1) the diagnosis and characterization at the pixel level of the forest spatial patterns and their individual constituents, which are mainly the core habitat areas and the structural connectors (bridges) between them, to (2) the assessment of their individual importance to uphold ecological fluxes as irreplaceable providers of structural connectivity. We present and show different analytical possibilities within the integrated workflow from where the manager can choose depending on the planning targets and on the characteristics of the ecological processes of interest. We illustrate the application of the combined approach in two forested areas in Central Spain with different scales and management contexts, in which the structural connectivity between forest habitat areas needs to be sustained. Our assessment was able to discriminate and highlight a concise subset of cores and bridges that concentrated most of the contribution to the overall connectivity and functioning of the forest habitat network. This provides clear guidelines on where the conservation management efforts should be targeted, allowing for many alternative areas where the rest of the management objectives and activities can be accommodated as required by the multifunctionality of forest resources. The proposed integrated approach can equally serve to identify (a) those forest areas that play a crucial role to sustain ecological fluxes that are to be promoted by management, such as the dispersal of native biota or (b) those sites where the spread of wildfires or invasive species can be halted more effectively. The potential of the proposed methodology to inform and guide forestry decisions is reinforced by the availability of the required analytical tools (Guidos and Conefor Sensinode) as freeware software packages.     

浅谈根河林业局森林经营规划

文章根据根河林业局森林资源现状,以现行的林业政策和法规为依据,本着可持续发展、生态优先的原则,分别针对公益林和商品林提出了今后林业局经营措施的具体规划。     

Effects of temporal aggregation in integrated strategic/tactical and strategic forest planning

Integrated approaches to forest planning lead to large models and there is a subsequent need for a reduction of the number of constraints and variables. One way of achieving this is to aggregate data, either spatially or temporally. In this paper an integrated forest planning mixed integer model that takes into account both long-term strategic and shorter-term tactical forest management decisions is utilised. The study analyses the consequences of temporal aggregation in the strategic part of the integrated model, whereas the tactical part is modelled by a fixed set of years divided into seasons. For reference, analyses are also made using a pure strategic linear programming model. Cases using both equal and variable strategic period lengths are presented, and two case study areas are used. Results indicate that integrated plans, as well as strategic plans, are not particularly affected by the number of equal length strategic periods when more than five periods, i.e. less than 20 year period length, are used. When modelling strategic and integrated problems using variable-length periods, care should be taken to ensure that harvest operations late in the planning horizon get enough timing options to be adequately described.     

森林多目标规划软件GISCAME及其生物量模块研究进展

在景观尺度,德国的GISCAME把权属、经营措施等森林经理学方法对森林功能与服务的影响加入到森林多目标规划中,对多权属区域森林多目标权衡分析具有重要意义。以生物量规划为例,该平台引入一种提高生物量和生态服务价值在时间和空间上动态权衡的土地利用策略模型,通过生长与收获模型结合的评估方法,解决了小班经营决策和区域规划目标不统一的问题,用情景分析来检验不同措施选择在应对气候变化和生物量增加要求上的差异。从森林经营管理的角度来看,该系统在生长与收获模型、森林调查数据、权属转换率、可及性、保护等级、皆伐或者间伐经营措施改变等方面还存在不确定性假设问题。为将GISCAME平台引进到我国森林经营管理中还需要加强嵌套精准模拟和景观资源可及性等问题研究,系统探索森林权属功能潜力及森林保护等级功能潜力数量差异,为森林景观精准规划与经营管理提供科学参考。     

国内外森林资源规划与模拟研究综述

森林资源规划的目的是设计在一段时间内和在一定空间中的积极干预,通过权衡具有不同社会功能的森林价值,使得在某一特定区域的特定功能价值最大化。文中在查阅国内外森林资源规划研究的基础上,系统分析了国内外森林资源规划系统及模拟核心内容。森林资源规划系统越来越受到国内外专业森林经营管理机构的青睐,专业化森林规划软件在推动森林生态服务价值模型建立、林分空间优化、复杂约束条件和目标分析中起到了积极的作用。在全球气候变化大背景下,未来农田与森林将被作为一个有机整体,开发多尺度、多数据复合的森林规划平台。     

Interactive Method for Supporting Forest Owners in Biodiversity Protection Decisions

Voluntary biodiversity protection tools have been adopted for practical use in many countries where non-industrial private forest ownership includes invaluable biodiversity resources. This has created a new kind of decision problem for individual forest owners: they should be able to define their conditions for entering into a biodiversity protection contract including sometimes a predetermined subsidy. This study presents a holding-level method for examining this decision problem. The method is based on utilization of interactive optimization where the possible subsidy has been included in the protection (no treatment) alternative of the examined stand. Generally, interactive optimization means that the landowner pinpoints the best plan by interactively studying and learning the production possibilities of his/her forest holding. Following changes made to the objective function by the forest owner, new solutions are presented for forest owners’ evaluation. If the “No treatments” option is selected in optimization for these areas, the forest owner would benefit more—in the current location of the production frontier and with the current subsidy—from entering into the protection contract than from cutting the specific forest area. In the case study, we demonstrate that the values of the holding-level goals, production possibilities of the planning area and the levels of the subsidy have a significant effect on the optimal decisions relating to biodiversity protection on the stand level.     

Integrating landscape connectivity in broad-scale forest planning through a new graph-based habitat availability methodology: application to capercaillie (Tetrao urogallus) in Catalonia (NE Spain)

The loss of connectivity of forest landscapes is seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation. In this context, explicitly incorporating connectivity considerations is an important challenge in current forest planning and management, but as yet there is a lack of operative methods for appropriate decision making in this respect. We describe a new methodology based on graph structures and a habitat availability index (integral index of connectivity) that integrates forest attributes (like habitat quality) and network connectivity in a single measure. We apply this methodology to examine the connectivity of the highly fragmented habitat of capercaillie (Tetrao urogallus) in Catalonia (NE Spain), where the threatened status of this forest bird species calls for landscape-level forest planning solutions. We analyse data on the distribution of capercaillie forest habitat at 1 km spatial resolution obtained from the recent Catalan Breeding Bird Atlas. We determine the functionally connected regions existing within its habitat distribution and identify the forest habitat areas that are more important for the maintenance of overall landscape connectivity for this species. Based on these results, we provide recommendations on certain critical public forests where management oriented to the conservation of capercaillie habitat is more necessary. These results highlight the potential and practical interest of the proposed methodology for successfully integrating landscape connectivity in broad scale forest planning.     

自然与人文相结合的森林公园景观规划探讨——以蒙山森林公园广场规划为例

以蒙山广场规划为例,通过分析公园的自然资源和人文资源及地方文化特点,根据广场的功能和城市广场的要求,提出了森林公园广场“自然、生态、绿色、个性”的规划理念,结合和利用公园丰富的植被和水资源,形成人与自然和谐,景观与功能一致的广场特色。     

Forecasting landscape-scale,cumulative effects of forest management on vegetation and wildlife habitat: A case study of issues,limitations, and opportunities

Forest landscape disturbance and succession models have become practical tools for large-scale, long-term analyses of the cumulative effects of forest management on real landscapes. They can provide essential information in a spatial context to address management and policy issues related to forest planning, wildlife habitat quality, timber harvesting, fire effects, and land use change. Widespread application of landscape disturbance and succession models is hampered by the difficulty of mapping the initial landscape layers needed for model implementation and by the complexity of calibrating forest landscape models for new geographic regions. Applications are complicated by issues of scale related to the size of the landscape of interest (bigger is better), the resolution at which the landscape is modeled and analyzed (finer is better), and the cost or complexity of applying a landscape model (cheaper and easier is better). These issues spill over to associated analyses that build on model outputs or become integrated as auxiliary model capabilities. Continued development and application of forest landscape disturbance and simulation models can be facilitated by (1) cooperative efforts to initialize more and larger landscapes for model applications, (2) partnerships of practitioners and scientists to address current management issues, (3) developing permanent mechanisms for user support, (4) adding new capabilities to models, either directly or as compatible auxiliary models, (5) increasing efforts to evaluate model performance and compare multiple models running on the same landscape, and (6) developing methods to choose among complex, multi-resource alternatives with outputs that vary over space and time.     

Predicting timber harvests from private forests—a utility maximisation approach

Forest owners’ values and the ownership structure of forest are changing continuously. One probable consequence of the current trends in Finland is that the significance of forest-related income will decrease, which may have a significant impact on the round wood supply. This study developed and demonstrated a new method, which allows policy makers to make forecasts on the future timber supply. The method is based on the assumed temporal changes in the distributions of the importance of different forest management goals. The distributions are converted into utility functions, generated separately for each forest holding. The utility functions are maximised, using heuristics, to obtain the optimal forest management plans for the holdings. The regional cutting budget is calculated by summing the removals of the optimal treatment schedules of stands over the whole area. The method was demonstrated by assuming four different scenarios for the forest management goals, in which the importance of net income from realised cuttings decreased by 0%, 25%, 50% or 100% in 60 years. The decrease was compensated for by an increased importance of the other goals, namely economic security, recreation, and nature values. The calculations were made with three different methods. Methods 1 and 2 derived the optimal plans directly for the whole 60-year period while Method 3 developed three consecutive 20-year plans. Method 2 assumed that the holding is sold or inherited once in 20 years with an abrupt change in the management goals. In Methods 1 and 3 the goals changed only gradually. The results were logical, indicating that the more the importance of net income decreases the lower the future timber supply will be.     

Integrating climate change into forest management in South-Central British Columbia: An assessment of landscape vulnerability and development of a climate-smart framework

The achievement of sustainable forest management requires the incorporation of risk and uncertainty into long-term planning. Climatic change will have significant impacts on natural disturbances, species and ecosystems, particularly on landscapes influenced by forest management. Understanding where vulnerabilities lie is important in managing the risks associated directly or indirectly with climatic change. The vulnerability of landscapes to natural disturbances, the resilience of ecosystems and distribution of species are all important components that need to be considered when undertaking forest planning, but climatic change is rarely factored into such planning. In this study, the vulnerability of fire potential, fire regimes, ecosystems and species to climatic change was modelled for a 145,000 ha landscape in the south-central interior of British Columbia, Canada. The results from these analyses were used to guide forest zoning, using the triad zoning framework, and for the development of a “climate-smart” management framework. The use of climate-smart management is advocated as a decision-making framework for managing forested landscapes based on an understanding of landscape vulnerability to future climatic change. From this understanding, the maintenance of ecosystem health and vitality could be achieved.     

我国沿海防护林复合经营技术研究进展

沿海防护林是在沿海地区建立的以防护为主要目的的林木和灌木林,在防灾减灾、护岸固堤、生物多样性保护及景观美化等方面具有重要作用。目前,我国对沿海防护林复合经营的研究重点集中在复合经营模式配置、复合经营关键技术以及功能与效益等方面。文中通过总结我国既有沿海防护林复合经营模式和经营技术等研究成果,对今后海防林复合经营研究进行了展望:1）与乡村振兴等战略紧密结合,重视复合经营项目的规划布局;2）提升复合经营科技含量,进行新品种、新技术和新模式研发;3）开展复合经营技术综合应用研究,建立试验示范基地,提高其生态、经济和社会效益。     

湖北宜昌西塞国森林公园规划设计探讨

以湖北宜昌西塞国森林公园为例,调查分析了该区自然条件,阐明了规划的指导思想、原则,对公园景区规划、植被规划、交通规划以及森林保护规划进行了探讨,提出以科学保护为前提、突出自然景观、点缀人工景点、融合人文景观的规划理念。     

Comparison of treewise and standwise forest simulators by means of quantile regression

Predicting forest development under varying treatment schedules forms the basis of forest management planning. The actual growth predictions are made with a forest simulator which includes growth equations and additional models for predicting a number of varying tree, forest and site properties. Forest growth simulators typically include either tree-level or stand-level growth models, but these two approaches have not been thoroughly compared. We set out here to compare these two approaches with the SIMO simulator framework in a small data set from southern Finland based on 60 sample plots in 30 stands, the development of which was known for 20 years. The stands chosen were very dense, so that the simulators could be tested under extreme conditions. The results show that the stand-level model is more accurate in almost all cases and its computational burden is much lower. It could therefore be advisable to use tree-level models for short-term predictions, which would ensure detailed information on forest structure for planning the near-future operations. Stand-level models would be more advisable in longer term predictions, especially when accurate volume estimates are considered more important than the forest structure. The errors observed in these simulators were analysed further by quantile regression, which allows empirical estimates of confidence intervals to be obtained for the simulator.     

A forest planning model for continuous employment in a forested village with primarily young stands in Korea

This paper presents a practical forest planning approach for continuous forest-based employment in a forested village with primarily young stands. The model is designed to find the practice level for continuous forest employment which embraces both the goal of maximizing the total forest employment and the constraint of maintaining its annual balance, considering forest size and condition, and budget available for forest practice. Through controlling the practice level with the help of a desired employment effect that contributes to allocating forest practices equally to each plan year, a marginal practice level can be found under which any practice level fulfills the goal and constraints. The potential practice area, which is determined by forest area, stand age, and practice schedule, contributes to determining the area silviculturally available for forest practice. Our forest planning model is focused on the planning of young forests which are not expected to yield merchantable products in the near term. The model can also be characterized by landscape-level forest planning in which stand-level practices are planned for achieving a forest-level goal of continuous forest employment. Thus, the model can serve as a basic planning tool for maintaining healthy forests as well as continuous forest employment in young forest areas, where forest-level goals are predicated on stand level practices.     

Multiple-use forest management in consideration of climate change and the interests of stakeholder groups

In this study, the overall utility of forest management alternatives at the forest management unit level is evaluated with regard to multi-purpose and multi-user settings by a multi-criteria analysis (MCA) method. The MCA is based on an additive utility model. The relative importance of partial objectives of forest management (carbon sequestration, ground water recharge, biodiversity, and timber production) is defined in cooperation with stakeholders. The forest growth model 4C (Forest Ecosystems in a Changing Environment) is used to simulate the impact of six forest management strategies and climate on forest functions. Two climate change scenarios represent uncertainties with regard to future climatic conditions. The study is based on actual forest conditions in the Kleinsee management unit in east Germany, which is dominated by Scots pine (Pinus sylvestris L.) and oak (Quercus robur L. and Quercus petraea Liebl.) stands. First, there is an analysis of the impact of climate and forest management on forest functions. Climate change increases carbon sequestration and income from timber production due to increased stand productivity. Secondly, the overall utility of the management strategies is compared under the priority settings of different stakeholder groups. From an ecological perspective, a conservation strategy would be preferable under all climate scenarios, but the business as usual management would also fit the expectations under the current climate due to high biodiversity and carbon sequestration in the forest ecosystem. In contrast, a forest manager in public-owned forests or a private forest owner would prefer a management strategy with an intermediate thinning intensity and a high share of pine stands to enhance income from timber production while maintaining the other forest functions.