Utility of Dynamic-Landscape Metapopulation Models for Sustainable Forest Management

Abstract:  We evaluated the utility of combining metapopulation models with landscape-level forest-dynamics models to assess the sustainability of forest management practices. We used the Brown Creeper ( Certhia americana ) in the boreal forests of northern Ontario as a case study. We selected the Brown Creeper as a potential indicator of sustainability because it is relatively common in the region but is dependent on snags and old trees for nesting and foraging; hence, it may be sensitive to timber harvesting. For the modeling we used RAMAS Landscape, a software package that integrates RAMAS GIS, population-modeling software, and LANDIS, forest-dynamics modeling software. Predictions about the future floristic composition and structure of the landscape under a variety of management and natural disturbance scenarios were derived using LANDIS. We modeled eight alternative forest management scenarios, ranging in intensity from no timber harvesting and a natural fire regime to intensive timber harvesting with salvage logging after fire. We predicted the response of the Brown Creeper metapopulation over a 160-year period and used future population size and expected minimum population size to compare the sustainability of the various management scenarios. The modeling methods were easy to apply and model predictions were sensitive to the differences among management scenarios, indicating that these methods may be useful for assessing and ranking the sustainability of forest management options. Primary concerns about the method are the practical difficulties associated with incorporating fire stochasticity in prediction uncertainty and the number of model assumptions that must be made and tested with sensitivity analysis. We wrote new software to help quantify the contribution of landscape stochasticity to model prediction uncertainty.     

A Comparison of Logging Systems and Bat Diversity in the Neotropics

Abstract:  Evaluating logging systems to determine which are most compatible with the maintenance of biodiversity is of prime importance if tropical forests are to be managed in a sustainable way. Bats are model taxa for this purpose. Two different logging systems are used in the natural forest of the Victoria-Mayaro Forest Reserve in Trinidad: open range and periodic block. Open range is a continuous harvesting system and, in common with most methods used to log tropical forests worldwide, has few harvest controls other than girth limits for selected species. Periodic block is a polycyclic system, with felling based on ecological criteria assumed to be compatible with the maintenance of biodiversity. To compare the effects of periodic block and open-range systems on biodiversity, we determined bat species richness and abundance in each system and in primary forest. We caught bats in mist nets set at ground level and in the canopy and in harp traps. In total 1959 individuals representing 38 species were captured. Species richness was similar among primary forest and logged forest habitats, although bat diversity was lower in logged forest. The distributions of bat species abundance did not differ significantly between logged forest and primary forest. We found, however, that both logging systems lead to a decrease in gleaning animalivores and an increase in frugivores. The increase in frugivores was likely the result of an increase in the abundance of bat-dispersed pioneer fruiting plants in logged forest. Bats of periodic-block-managed forest were more similar to those of primary forest than those of forest logged using the open-range system, indicating that the periodic-block system is more compatible with the maintenance of bat diversity. Our results support the suggestion that the measured use of tropical forests can largely be compatible with biodiversity conservation.     

昆山市城市森林生态建设规划

通过对昆山市森林生态现状及城市建设中存在问题的分析,结合国际城市生态发展的趋势,提出了由三环、两区、一链、四横、三纵、四大片为基本骨架的昆山市森林生态建设总体布局,为昆山市今后的森林生态建设提出思路和对策。     

城市生态研究概述

本文阐述了城市生态学的起源、发展过程和研究内容，以及国内外城市生态学研究进展；研究了我国城市主要生态环境问题及对策。并提出生态城市是人类可持续发展城市的理想模式。     

植物次生代谢:功能、调控及其基因工程

植物次生代谢物具有多种重要的生物学功能 ,在工农业生产和人们日常生活中具有广阔的应用前景 .随着可持续农业的发展 ,植物次生代谢物的化学生态学功能及其对农产品品质的影响倍受关注 .植物次生代谢调控的生物化学、分子生物学和基因工程已成了当今国际生物界十分活跃的前沿研究领域 .本文仅就植物次生代谢物功能、代谢调控及基因工程研究进行简要的概述 .1　植物次生代谢物的功能1.1　植物次生代谢物的化学生态学功能植物次生代谢物按其合成方式可分为组成型和诱导型两种类型 ,它们在植物与植物、植物与微生物及植物与昆虫之间的关系中行…     

光(温)敏核不育水稻生态及生理生化研究概述

本文介绍了光、温敏核不育水稻在生态及生理生化方面取得的主要成就.着重概述了光、温敏核不育水稻雄性育性转换的光温生态条件,育性转换过程中蛋白质、氨基酸、酶活性、ATP及内源植物激素持续变化.另外,对光、温敏不育水稻研究存在的问题进行了分析.     

岳阳市城市扩张期环境生态可持续发展

在已有可持续发展理论的基础上，以岳阳市环境生态为研究对象，利用主成分分析法、层次分析法（AHP）和德尔斐的方法计算和分析在城市化过程中环境生态变化情况，论述了这一过程中环境生态存在的问题和产生的原因，对目前小城市向中等城市转变过程中避免和解决环境生态问题提供了例证。     

Forest cover dynamics in the Selva Maya of Central and Southern Quintana Roo,Mexico: deforestation or degradation?

ABSTRACT

Forest cover dynamics (1993-2018) was assessed in two regions on the Yucatan Peninsula: Zona Maya (ZM), 67% indigenous with shifting cultivation and community forestry; and Bacalar–Rio Hondo (BRH), mainly commercial agriculture and pastureland. Degradation (12,915 ha y^?1) exceeded deforestation (5882 ha y^?1) and was worse in BRH. In BRH there was a net forest loss (?1.6% y^?1) associated with pastureland and commercial agriculture. In ZM, mature forest recovery (1.4% y^?1) and dynamic forest cover (continuous loss and gain) were associated with shifting cultivation. Changes were more intense during 2011–2018 and gains of mature forest in ZM and deforested areas in BRH targeted secondary vegetation. Fragments of mature and secondary vegetation decreased, and connectivity improved in ZM, but opposite trends occurred in BRH. Reporting and monitoring deforestation using Global Forest Watch data is inadequate since 62% of forest cover loss represent degrading or recovering forest cover.     

On the random placement hypothesis

A traditional method of summarizing spatial distribution of species is the observed species-area curve. Often the observed species-area curve is surprisingly close to the expected species-area curve under the hypothesis of random placement of individuals. This has been used as evidence supporting the hypothesis. In this paper, we argue that using the observed species-area curve to test the general random placement hypothesis is highly inefficient. We present a testing method based on the classical ² test for over-dispersion which is not only more efficient but also applicable to situations where complete abundance information are unavailable. We also discuss three alternatives of the hypothesis. The focus of this paper is on these and other general issues relevant to communities of different types. No applications are included in this paper.     

Antennal responses of the western pine beetle, <Emphasis Type="Italic">Dendroctonus brevicomis</Emphasis> (Coleoptera: Curculionidae), to stem volatiles of its primary host, <Emphasis Type="Italic">Pinus ponderosa</Emphasis>, and nine sympatric nonhost angiosperms and conifers

Summary. Stem volatile extracts from ten trees that are sympatric with the western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae) were assayed by gas chromatographic-electroantennographic detection analysis (GC-EAD). The extracts were from the primary host, ponderosa pine, Pinus ponderosa Dougl. ex Laws. (Pinaceae); two nonhost angiosperms, California black oak, Quercus kelloggii Newb. (Fagaceae), and quaking aspen, Populus tremuloides Michx. (Salicaceae); and seven nonhost conifers, white fir, Abies concolor (Gord. & Glend.) Lindl. ex Hildebr. (Pinaceae), incense cedar, Calocedrus decurrens (Torr.) Florin (Cupressaceae), Sierra lodgepole pine, P. contorta murrayana Grev. & Balf. (Pinaceae), Jeffrey pine, P. jeffreyi Grev. & Balf. (Pinaceae), sugar pine, P. lambertiana Dougl. (Pinaceae), Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco (Pinaceae), and mountain hemlock, Tsuga mertensiana (Bong.) Carr. (Pinaceae). Sixty-four compounds were identified from the ten trees, 42 of which elicited antennal responses in D. brevicomis, usually in both sexes. In addition, several synthetic compounds, including a number of the antennally-active compounds from the extracted trees and some bark beetle pheromone components, elicited antennal responses in a manner similar to that observed with the extracts. Of the antennally-active compounds known to be present in trees sympatric with D. brevicomis, only geraniol was unique to its host. Four antennally-active compounds were found in the host and in other conifers; five compounds were found only in nonhost conifers; eight compounds were found in either or both of the nonhost angiosperms; eight compounds were found in either or both of the angiosperms and in nonhost conifers, but not in the host; and 19 were found in both the host and in angiosperms and/or nonhost conifers. Several bark beetle pheromone components were found in the stem volatile extracts. Conophthorin was identified from both nonhost angiosperms; exo-brevicomin was identified in A. concolor; verbenone was identified from a number of nonhost conifers; and chalcogran was identified from P. tremuloides. The number of nonhost volatile chemicals that D. brevicomis encounters and is capable of detecting, and the diversity of sources from which they emanate, highlight the complexity of the olfactory environment in which D. brevicomis forages. This provides a basis for further work related to chemically-mediated aspects of foraging in this insect and perhaps other coniferophagous bark beetles, and highlights the need to consider foraging context in the design and implementation of semiochemical-based management tactics for tree protection.