Predicting a ‘tree change’ in Australia's tropical savannas: Combining different types of models to understand complex ecosystem behaviour

In this study, key ecological modelling limitations of a process-based simulation model and a Bayesian network were reduced by combining the two approaches. We demonstrate the combined modelling approach with a case study investigating increases in woody vegetation density in northern Australia's tropical savannas. We found that by utilising the strengths of a simulation model and a Bayesian network we could both forecast future change in woody vegetation density and diagnose the reasons for current vegetation states. The local conditions of climate, soil characteristics and the starting population of trees were found to be more important in explaining the likelihood of change in woody vegetation density compared to management practices such as grazing pressure and fire regimes. We conclude that combining the strengths of a process and BN model allowed us to produce a simple model that utilised the ability of the process model to simulate ecosystem processes in detail and over long time periods, and the ability of the BN to capture uncertainty in ecosystem response and to conduct scenario, sensitivity and diagnostic analysis. The overall result was a model that has the potential to provide land managers with a better understanding of the behaviour of a complex ecosystem than simply utilising either modelling approach in isolation.     

Simulating the impacts of fire: A computer program

Recurrent fire has played a dominant role in the ecology of southwestern ponderosa pine forests. To assess the benefits or losses of fire in these forests, a computer simulation model, called BURN, considers vegetation (mortality, regeneration, and production of herbaceous vegetation), wildlife (populations and habitats), and hydrology (streamflow and water quality). In the formulation of the model, graphical representations (time-trend response curves) of increases or losses (compared to an unburned control) after the occurrence of fire are converted to fixedterm annual ratios, and then annuities for the simulation components. Annuity values higher than 1.0 indicate benefits, while annuity values lower than 1.0 indicate losses. Studies in southwestern ponderosa pine forests utilized in the development of BURN are described briefly.     

火灾风险等级评估的专家软件系统建设的探讨

目前 ,我国在火灾风险等级评估的专家软件系统建设方面的研究较少 ,笔者在该方面进行了研究和探索。在简要介绍了国内外对火灾风险等级评估专家软件系统的研究现状的基础上 ,阐述了火灾风险等级评估的相关概念 ;提出了一套建立火灾风险等级评估专家软件系统的思路 ;然后从人工智能的角度出发 ,综合考虑火灾风险等级评估的特殊性 ;设计了基本的火灾风险等级评估认定专家系统的结构 ,并讨论了如何建设该专家软件系统。该探索结果所提出的建设火灾风险等级评估的专家软件系统的思路和方法可为相关研究工作提供参考。     

高层建筑火灾风险评估中一种具有置信度和方差的权系数

对评估中的权系数引入置信度和方差两个概念 ,为权系数提供更多的信息 ,便于决策者采用 ;针对作者在香港所作的高层建筑火灾风险因子评估系数 ,得到 16个风险因子的带置信度和方差的权系数 ,为火灾风险评估提供重要依据     

火灾报警系统可靠性数字仿真软件研究

介绍了火灾报警系统可靠性数字仿真原理和软件设计方法，并举出了运行实例，证明数字仿真技术在火灾报警系统可靠性分析方面具有良好的应用前景。     

Predicting mosaics and wildlife diversity resulting from fire disturbance to a forest ecosystem

A model for predicting community mosaics and wildlife diversity resulting from fire disturbance to a forest ecosystem is presented. It applies an algorithm that delineates the size and shape of each patch from grid-based input data and calculates standard diversity measures for the entire mosaic of community patches and their included animal species. The user can print these diversity calculations, maps of the current community-type-age-class mosaic, and maps of habitat utilization by each animal species. Furthermore, the user can print estimates of changes in each resulting from natural disturbance. Although data and resolution level independent, the model is demonstrated and tested with data from the Lewis and Clark National Forest in Montana.     

Evaluation of a fire behavior information integration system for southern California chaparral wildlands

Close contact between arid, fire-vulnerable chaparral wildlands and urban development in southern California results in conflagrations that have burned 200,000 ha, destroyed 700 structures, and claimed 16 lives in a single year. In 1972, the U.S. Congress established FIRESCOPE to assist southern California fire and emergency agencies and to develop computer methods for the simulation of wildland fire behavior.     

基于超媒体技术的建筑火灾数据编辑器

本文介绍了一种基于超媒体技术的建筑火灾数据编辑器基本原理和实现方法,该编辑器是建筑物火灾危险度评估系统的一个组成部分。     

Forest-user attitudes toward alternative fire management policies

The formulation and implementation of new fire policies in the national forests depend upon public acceptance. A national survey of organized groups of forest users indicates that, contrary to the concern of many forest managers, considerable support exists for flexible fire suppression policies. Forest users are also willing to accept the risk associated with the manager's use of prescribed fire. However, important intergroup differences do exist. Such variation is discussed in relation to a number of socioeconomic variables, general fire knowledge, specific knowledge about the effects of low-intensity fires, and risk preference levels.     

Implementation of two new resource management information systems in Australia

This paper describes the development and implementation ofPREPLAN, A Pristine Environment Planning Language and Simulator, for two conservation areas in Australia, Kosciusko National Park (New South Wales) and Tutanning Nature Reserve (Western Australia).PREPLAN was derived from the North American gradient modeling systems and theForest Planning Language and Simulator (FORPLAN), but includes unique characteristics not previously available.PREPLAN includes an integrated resource management data base, modules for predicting site-specific vegetation, fuels, animals, fire behavior, and fire effects, and an English language instruction set.PREPLAN was developed specifically to provide available information and understanding of ecosystems to managers in a readily accessible and usable form, and to provide the motivation to conduct additional required research projects. An evaluation of the system's advantages and limitations is presented, and the way the utilization of such systems is improving natural area decision making throughout Australia is discussed.