生物多样性的功能

生物多样性包括遗传、物种、生态系统与景观多样性。从以下几个方面综述了生物多样性的功能：①稳定生态系统的作用;②提高生态系统生产力的作用;③生物多样性对生态系统可持续性的作用;④生物多样性在农业生产上的作用;⑤生物多样性在医学上的作用;⑥生物多样性在工业上的作用。     

Modelling of Energy Flow, Rotational Grazing and Potential Productivity in an Alpine Meadow Grazing Ecosystem

An eight-compartment model of the energy dynamics of an alpine meadow-sheep grazing ecosystem was proposed based on SHIYOMI's system approach. The compartments were the above-ground plant portion, the underground live portion including roots, the underground dead portion including roots, the above-ground litter Ⅰ (degradable portion), the above-ground litter Ⅱ (undegradable portion), the sheep intake, the sheep liveweight, and the faeces. Energy flows between the eight compartments were described by eight simultaneous differential equations. All parameters in the model were determined from paddock experiments.The model was designed to provide a practical method for estimating the effects of the number of rotational grazing subplots, grazing period, and grazing pressure on the performance of grazing systems for perennial alpine meadow pasture. The model provides at least 28 different attributes for characterizing the performance of the grazing system. Analyses of 270 simulated rotational grazing systems of summer-autumn meadow pasture (grazing from 1st June to 30 October each year) provided an inference base to support two recommendations concerning management variables. First, with a three-paddock, 29-day grazing period and 30.14kJ·m-2·day-1 grazing pressure scheme, the system has the highest total grazing intake, 4250.44 kJ·m-2, during the grazing season. Secondly, with a three-paddock, 7-day grazing period and 28.89kJ·m-2·day-1 grazing pressure scheme, the accumulated graze is 4073.34kJ*m-2.The potential productivity of the alpine meadow under grazing is defined in this paper as the maximal dry biomass of herbage grazed by the grazing animals over the whole growing season. It has been analysed by applying optimal control theory to the model. The productivity is regarded as the objective function to be maximized through optimization of the time course of the grazing pressure, the control variable. The results show that: (1) under constant grazing pressure, the optimal grazing pressure is f16=25.90kJ·m-2·day-1 (f46=f56=0) with the highest accumulated intake of J(1)=3268.17kJ·m-2; and (2) the optimal grazing pressure is f16=25.94kJ·m-2·day-1 (f46≠0, f56≠0) with the maxial accumulated intake J(145)=3500.39kJ·m-2. Under variable grazing pressure, the dynamics of optimal grazing pressure is shown in Fig.6(a) and Eqs. (9)(11), while the potential productivity (the highest accumulated intake) is J(145)=8749.01kJ·m-2, 2.5 times the constant grazing pressure.     

淮河水污染及其治理的现状和展望

提出应用流域生态系统的理论促进淮河水污染治理 ,并提出当前宜先行研究的若干方面。     

大坝对河流生态系统的环境影响分析

在分析河流生态系统特征的基础上,从河流生态系统的非生态变量和生态变量角度研究了大坝对河流生态系统等方面的影响,认为大坝在发挥调蓄区域水资源、降低洪涝灾害、获得清洁能源等重要作用的同时,也对河流系统水文情势、形态、地貌、水质以及生态环境产生了不利影响,并建议大坝建设者和管理者通过应用现代技术、深入开展环境影响评价、制定利于生态环境的大坝运作模式等手段来减轻大坝对河流生态系统环境等方面的影响,实现可持续发展．     

熵理论及其应用

熵是物理化学中的一个重要概念。本文简介了熵理论的建立、发展和泛化过程,用负熵理论分析了熵在生命科学、医药学和生态环境中的应用,使人类认识到构建和谐社会的重要性。     

三峡库区东河河流等级及生态结构分析

利用GIS技术进行河流等级结构划分,研究了三峡库区东河流域河流的等级体系.将整个东河流域河溪分为6级,并在此基础上研究了不同等级河溪与海拔高程和坡度的关系.研究发现,河溪在由低等级向高等级变化时,其空间分布范围逐渐由坡度大、海拔高向坡度小、低海拔的平缓地带过渡;低等级溪流周围植被生长状况好于高等级溪流周围植被.东河1、...     

基于能值理论的城市复合生态系统可持续发展评价

城市可持续发展需要协调好城市经济、社会发展和城市环境之间的关系,城市生态系统可持续发展评价,可为促进生态城市建设、维护城市生态平衡和区域人口的合理分布等提供依据.郑州市作为中原城市群经济隆起带的展示窗口,最近几十年,随着城市的发展,其现代化的需求、密集的人类活动、快速的结构性增长和高物耗、高污染的产业发展对郑州市生态系统的威胁很大,可持续发展压力大.本文借助能值理论构建了城市生态系统的评价指标体系,以能值为量纲,统一度量城市复合生态系统的发展水平和可持续状况.郑州市的实例应用显示,近几年郑州市城市发展迅速,但环境压力很大,可持续状况不容乐观.     

在不确定性下培育产业创新生态系统以中国智能网联汽车行业为例

本研究探讨了产业创新生态系统理论,并选取我国智能网联汽车产业作为研究对象。通过主成分分析和回归分析,选取7个大项16个小项的衡量指标,采用2010~2019年数据探索了产业创新生态系统的影响因素及其对产业创新生态系统的影响程度。根据实证分析的结果,梳理了3个主要影响方面。同时,分析了在不确定的环境下,智能网联汽车产业创新生态系统的核心影响因素,最后得出4个主要影响方向和相互影响程度。     

林芝市生态保护重要性评价与生态功能区划

本研究以西藏自治区林芝市为例,利用GIS技术,开展栅格尺度生态系统服务功能重要性与生态脆弱性评价,集成划分生态保护重要性等级,并以此为基础,划分了林芝市生态功能分区。结果表明：1)林芝市生态保护重要性水平整体较高,极重要区、重要区分别占全市总面积的62.6%和28.1%;2)林芝市森林生态系统生物多样性维护、水源涵养、水土保持功能重要性较高,应加大森林资源保护力度;3)以乡镇为单元,将林芝市划分为7个生态功能区,并阐释了生态保护重点方向。基于生态系统服务功能重要性、生态脆弱性空间分异状况研究的功能区划方案,有助于生态保护实施分区、分类管理,为推进林芝市生态系统保护与修复提供科学基础。     

“山水林田湖草沙”的形成、功能及保护

“山水林田湖草沙”是对我国多样化生态系统的简要概括和通俗表达。它们在外观和结构上存在明显差异,但又相互联系、相互影响,共同构成生命共同体,为人类社会延续发展提供物质基础和必要条件。当前,“山水林田湖草沙”的一体化治理、保护和修复,已成为推动我国生态文明建设的重要抓手。文章较为系统地总结了我国“山水林田湖草沙”的本底情况,简要介绍它们形成的条件和原因,并从生产、生态、文化与景观等三个方面阐述各自的主要功能。在此基础上,文章基于生态学视角,对生态文明建设中应如何开展“山水林田湖草沙”的治理、保护和利用进行了讨论,回顾国内外若干对生态环境产生负面影响的案例,并简要阐述生态文明建设的生态学途径。