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林业建设工程的环境背景调查和环境质量评估 总被引：3，自引：0，他引：3
林业建设工程的目标已由过去的木材及林产品产向发挥林业环境效益等多重功能转化，特别强调了现代林业建设乃是人类最积极的环境建设途径。现代林业工程必须在立项和建设实施前进行工程建设区的环境背景现有环境质量的评估，对建议经营目标实施后的环境进行预测，并在实一人埋藏后进行其环境效益的评价。本文对前者，即工程前的环境背景调查和环境质量评估，提出了技术要求，对农业建设工程也有参考意义。 相似文献
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林业建设工程的环境预测与环境效益评估 总被引：3，自引：0，他引：3
本文在林业建设工程的环境背景调查和环境质量评估基础上，对工程实施完成后一个时期的环境效益预测提出了预测和评估的内容，效益指标和方法供讨论，以其逐步实行对林业建设工程项目环境预测及评估的规范化和体系化。 相似文献
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城市林业的兴起 城市林业(urban forestry)约在20世纪下半叶在西方兴起,是指要发展为城市服务的林业。主要特点是突破了过去长久以来以城市市区绿化、美化为目标的狭义的城市绿化,发展成为为城市生态系统服务的林业体系。因为西方快速现代城市化的后果是市区高空建筑密集,绿化空间狭小,其结果是只能在钢筋水泥建筑群中形成斑点、小块 相似文献
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<正> 一、21世纪是生态世纪 20世纪是人类文明飞速发展的世纪,据资料统计,20世纪的科技成就,已相当于前19个世纪文明科技史的总和。20世纪是世界发生巨大变化的100年。全球以不变价计算的国内生产总值增长约30倍,人口增长不足3倍,人类的生活水平迅速提高。全球60 相似文献
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Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for biodiversity conservation and ecosystem sustainability. Evergreen broad-leaved woody plants(EBWPs) are important components of numerous biomes and are the main contributors to the flora south of 35°N in China. We calculated the grid cell values of species richness(SR) for a total of 6265 EBWP species in China, including its four growth-forms(i.e., tree, shrub, vine, and bamboo), and estimated their phylogenetic structure using the standardized phylogenetic diversity(SPD) and net relatedness index(NRI). Then we linked the three biogeographical patterns that were observed with each single environmental variable representing the current climate, the last glacial maximum(LGM)–present climate variability, and habitat heterogeneity, using ordinary least squares regression with a modified t-test to account for spatial autocorrelation. The partial regression method based on a general linear model was used to decompose the contributions of current and historical environmental factors to the biogeographical patterns observed. The results showed that most regions with high numbers of EBWP species and phylogenetic diversity were distributed in tropical and subtropical mountains with evergreen shrubs extending to Northeast China. Current mean annual precipitation was the best single predictor. Topographic variation and its effect on temperature variation was the best single predictor for SPD and NRI. Partial regression indicated that the current climate dominated the SR patterns of Chinese EBWPs. The effect of paleo-climate variation on SR patterns mostly overlapped with that of the current climate. In contrast, the phylogenetic structure represented by SPD and NRI was constrained by paleo-climate to much larger extents than diversity, which was reflected by the LGM–present climate variation and topog-raphy-derived habitat heterogeneity in China. Our study highlights the importance of embedding multiple dimensions of biodiversity into a temporally hierarchical framework for understanding the biogeographical patterns, and provides important baseline information for predicting shifts in plant diversity under climate change. 相似文献
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河南宝天曼化香林特征及物种多样性 总被引：2，自引：0，他引：2
根据10块样地的野外调查材料,对河南宝天曼化香林的土壤性质、植物区系成分、群落外貌、群落结构以及物种多样性特征进行了初步分析。结果表明:(1)化香林土壤较贫瘠,区系组成较丰富,其属的分布类型以温带性质的属最多,热带性质的属也占一定比例;(2)化香林的生活型以高位芽为主,叶级谱中以中型叶为主;(3)化香林的垂直结构可分为乔木层、灌木层、草本层,亦有少量的层间植物;(4)化香林的优势种显著,群落物种的丰富度、多样性、均匀度指数的总趋势为灌木层>草本层>乔木层,但在海拔梯度上的分布并未表现出明显的规律性。 相似文献
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