Impacts of daily weather variability on simulations of the Canadian boreal forest

This study examines the importance of climate variability when simulating forest succession using a process-based model of stand development. The FORSKA-2V forest gap model, originally developed for forcing with monthly mean climate data, was modified to accept daily weather data. The model's performance was compared using different temporal resolutions of forcing along a bioclimatic transect crossing the boreal region of central Canada, including the aspen-parkland and forest-tundra ecotones. Forcing the model with daily weather data improved the simulation of key attributes of present-day forest along the transect, particularly at the ecotones, compared to forcing with monthly data or long term averages. The results support the hypothesis that climatic variability at daily time-scales is an important determinant of present-day boreal forest composition and productivity. To simulate boreal forest response to climatic change it will be necessary to create climatic scenarios that include plausible projections of future daily scale variability.     

Prospects for Restoring the Biodiversity of Steppe Vegetation: Sowing of Perennial Grasses

Russian Journal of Ecology -     

On the Problem of Assessing the Resistance of Planktonic Community to Adverse Influences

An experimental-analytical method for assessing the vulnerability of aquatic ecosystems under conditions of anthropogenic pollution is considered. Such data are very important for estimating economic damage from accidental environmental pollution and determining the seasons in which industrial activities will be less hazardous in ecological terms. A feasible approach to this problem is based on the study of ecosystem behavior under critical conditions. Phytoplankton, being the main primary producer of organic matter in the aquatic ecosystem, is the key element providing for its stability.__________Translated from Ekologiya, No. 4, 2005, pp. 294–299.Original Russian Text Copyright © 2005 by Domnin, Korsak, Mosharov.     

城市群的生态研究方向:城市群落学解析

城市群落是若干城市在共同的生境条件下通过竞争、共生等生态行为所形成,并与环境相互作用的城市群体,是具有协同进化、演替等生态功能的有机体.运用群落生态学的理论、方法对群落中城市种群间的关系、城市群落的结构特征及城市群落演替等方面进行研究,试图探求促进城市群落持续发展的规律.首先界定城市群落、城市群落学等相关概念,构建城市群落学理论框架;其次对比分析了生物群落与城市群落的特征和生态功能上的相似性和差异性;最后阐述了有关城市群落的种群组成、种间关联、群落结构及群落演替的研究内容,并提出了相应的城市群落研究方法.从生态学角度来看城市问题,借鉴群落生态学的原理和研究方法来认识城市群的发展,是"回归自然"的城市发展观点,有利于促进城市群落功能的发挥,推动城市群落向特定的方向演替.     

长白山阔叶红松林不同演替阶段地表甲虫组成和多样性(英文)

鞘翅目昆虫多样性的变化是森林演替过程的综合反映.于2007年6~8月采用陷阱诱捕法对长白山阔叶红松林带不同演替阶段地表甲虫物种组成和数量进行了调查,并分析了该地区不同演替阶段地表甲虫多样性的变化趋势及主要生境因子对地表甲虫群落的影响.结果显示,长白山阔叶红松林内共诱捕地表甲虫23种,共511头,隶属于10个科.其中个体数最多的为埋葬甲科,物种数最多的为步甲科,优势类群为步甲科和埋葬甲科.不同演替阶段中,次生白桦林地表甲虫物种数和个体数高于原始阔叶红松林和次生针阔混交林,3个生境内地表甲虫多样性无显著差别.地表甲虫高峰期为7月份.不同演替阶段的样地中物种统计数量都没有达到渐进线,次生白桦林样地中实际物种只占估计值的67%,其它2个生境实际物种数都在物种估计值的95%区间范围内,略低于平均值.3个生境的地表甲虫种-多度曲线无显著差异,符合对数分布.胸高断面积和土壤湿度对地表甲虫的分布有显著影响,它们可以解释99.2%的物种与环境之间的关系.     

鼎湖山南亚热带森林生态系统服务价值动态

以鼎湖山3个南亚热带森林演替典型阶段生态系统为对象,采用我国《森林生态系统服务功能评估规范》（LY/T 1721—2008）标准化计算公式与服务价格,量化揭示南亚热带森林生态系统演替过程中生态系统服务功能价值动态。结果表明：随着演替的进行,南亚热带森林生态系统服务功能总价值不断增大;但各分项服务功能价值则表现出不同的动态规律与变化幅度,从而使得森林生态系统服务结构呈现非线性演化特征。在南亚热带森林生态系统演替的早期阶段,生态系统服务价值的最大组分是涵养水源的功能价值,而中、后期则是保育土壤。人工林营造可以有效增强区域生态系统的水源涵养能力,而保育演替中、后期森林则对于大气CO2收和土壤保育而言尤为重要。     

Evaluation of fire as a management tool for controllingSchinus terebinthifolius as secondary successional growth on abandoned agricultural land

Schinus terebinthifolius, native to South America, has become an aggressive woody weed in southern Florida, displacing native vegetation as well as rapidly invading disturbed sites. Studies to evaluate the effectiveness of fire as a management option for controllingSchinus on abandoned farmland in Everglades National Park, known as the “Hole-in-the-Donut,” began in 1979. Study plots were established to monitor any change(s) in herbaceous cover and in numbers and size ofSchinus stems. Except in the control plot (which was not burned), each site was burned as often as fuel conditions permitted (usually once every one or two years), through 1985. Results indicated that both the number and density ofSchinus stems increased over the course of the study. While plots that burned showed a reduction in the rate ofSchinus invasion, invasion still progressed rapidly with or without the occurrence of fire. The increase inSchinus stem density from 1980 to 1985 was highly significant in all transects except one. Herbaceous cover showed no clear trends relative to burning.     

Succession in the Abra ovata Community on Soft Grounds of a Newly Flooded Area of the Caspian Sea

Studies on succession in the Abra ovata community inhabiting the flooded area in Sulak Bay, Caspian Sea, that have been carried out since the mid-1980s were continued. It has been found that the pioneer species A. ovata and Cerastoderma glaucum are still dominant in the structure of this community, determining the course of its succession. Its second stage does not fit the framework of the models characteristic of benthic communities. On the one hand, it conforms to the tolerance model: the pioneer species A. ovata, despite its dominance at all stages of succession, has not prevented the spread of other numerous colonizers of the same trophic level. On the other hand, it conforms to the facilitation model: due to their abundance, the pioneer species as grazing species have attracted organisms of a higher trophic level, namely, sturgeons.     

疏勒河中下游绿洲胡杨种群结构与动态研究

通过在疏勒河中下游天然胡杨林区设置7个样方6.852 4 hm²,采用相邻格子法和动态数量值,分析胡杨种群的结构与动态特征。结果表明:中下游及不同生境胡杨种群年龄结构差异显著。中游幼苗缺失,幼树不多,中树最多,占总数的72.15%,大树较多,老树甚少,年龄结构呈正态分布型,林分年轻、稠密、高大,每公顷胡杨总数是下游的13.45倍。下游幼苗缺失,幼树极少,中树较多,大树最多,大、老树占总数的62.54%,年龄结构呈倒金字塔型,林分偏老,稀疏、矮小。中下游均为衰退种群。胡杨种群存活曲线基本接近Deevey I型,为下降种群;且存活率幼、中树高于大、老树,中游明显高于下游。种群数量动态计算表明,幼、中树动态量值为负值,大树、老树为正值,但胡杨总体表现为衰退的结构动态关系。总之,研究区胡杨未来因幼苗缺乏而趋于衰退演替,且下游衰退演替的速度更快。     

中国低碳经济发展的渐进式路径

在对国际低碳经济发展的路径类型及其演进过程深入考察的基础上,基于现实利益和基本国情对中国低碳发展的渐进式路径进行了论证,并顺应低碳经济发展的趋势,创造性地提出了我国低碳发展的五步走战略,明确了渐进式低碳发展的路线图。