紫色土硅酸盐细菌的表型特征及溶磷解钾能力

对40株分离自四川、重庆等地的代表笥紫色土中的硅酸盐细菌和1株参照菌株进行了52个表型性状的数值分析，探讨了硅酸盐细菌液体振荡培养后pH值、菌数变化与溶磷、解钾量之间的关系，结果表明：紫色土硅酸盐细菌绝大部分属于胶胨样芽孢杆菌（Bacillus mucilaginosus），但在个体和群体生长特征、碳氮源利用、硝酸盐还原能力、耐Ⅰ菌株在86％相似水平分为2个亚群，不同的硅酸盐细菌菌株的溶磷、解钾特性差异较大，具有溶磷解钾双重特性的菌株约占供试菌株（含参考菌株）的22％，只具溶磷特性的约占29％,其溶磷效果较显著（有效磷增加最高达40.64%），而解钾效果不明显（有效钾增加最多的只有7.9%）。供试紫色土硅酸盐细菌的溶磷、解钾特性与菌株生长过程中产酸有关，其溶磷、解钾量与培养液中pH值的降低呈正相关，图5表3参20。     

Nonparametric estimation of Shannon’s index of diversity when there are unseen species in sample

A biological community usually has a large number of species with relatively small abundances. When a random sample of individuals is selected and each individual is classified according to species identity, some rare species may not be discovered. This paper is concerned with the estimation of Shannons index of diversity when the number of species and the species abundances are unknown. The traditional estimator that ignores the missing species underestimates when there is a non-negligible number of unseen species. We provide a different approach based on unequal probability sampling theory because species have different probabilities of being discovered in the sample. No parametric forms are assumed for the species abundances. The proposed estimation procedure combines the Horvitz–Thompson (1952) adjustment for missing species and the concept of sample coverage, which is used to properly estimate the relative abundances of species discovered in the sample. Simulation results show that the proposed estimator works well under various abundance models even when a relatively large fraction of the species is missing. Three real data sets, two from biology and the other one from numismatics, are given for illustration.     

A Natural Experiment on the Impact of Overabundant Deer on Forest Invertebrates

Abstract:  In large parts of North America and Europe, deer overabundance threatens forest plant diversity. Few researchers have examined its effects on invertebrate assemblages. In a natural experiment on Haida Gwaii (British Columbia, Canada), where Sitka black-tailed deer ( Odocoileus hemionus sitkensis ) were introduced, we compared islands with no deer, with deer for fewer than 20 years, and with deer for more than 50 years. We sampled invertebrates in three habitat categories: forest edge vegetation below the browse line, forest interior vegetation below the browse line, and forest interior litter. In forest edge vegetation, invertebrate abundance and species density decreased with increasing length of browsing history. In forest interior vegetation, decrease was significant only on islands with more than 50 years of browsing. Insect abundance in the vegetation decreased eightfold and species density sixfold on islands browsed for more than 50 years compared with islands without deer. Primary consumers were most affected. Invertebrates from the litter showed little or no variation related to browsing history. We attributed the difference between vegetation-dwelling and litter-dwelling invertebrates to differences in the effect of browsing on their habitat. In the layer below the browse line deer progressively removed the habitat. The extent of litter habitat was not affected, but its quality changed. We recommend more attention be given to the effect of overabundant ungulates on forest invertebrate conservation with a focus on edge and understory vegetation in addition to litter habitat.     

日本琵琶湖流域生态系统的修复与重建

琵琶湖流域生态系统的修复与重建着眼于全流域及中长期目标的实现. 在《琵琶湖综合保全整备规划》基础上,滋贺县政府提出了流域生物生息空间网络化构筑的长期构想,在全流域划定了16个重要生物生息空间及10条重要河流作为生态回廊;从上游的森林建设、内湖重建、河流治理到湖滨带芦苇群落的保护等开展了一系列的流域修复工作,如针对湖滨带修复,制定了芦苇群落保护条例与规划,划定了琵琶湖湖岸及周边内湖的芦苇群落保护与恢复区域,面积达138 hm2,其中芦苇带栽植面积达15 hm2,收割等维护管理每年达30 hm2等. 琵琶湖修复与重建工程的开展使生物多样性逐渐提高,生态系统功能得到恢复. 与之相比,我国湖泊流域生态修复存在的问题主要体现在生态修复缺乏流域整体的长远规划以及在湿地修复、低污染尾水的生物处理、湖滨带修复等领域存在一定的理念差异.      

青藏高原不同海拔梯度厌氧氨氧化细菌丰度及其生物多样性空间分布

厌氧氨氧化作为新型微生物氮循环过程,已经成为国内外研究热点.目前对厌氧氨氧化细菌的研究主要集中在海洋生态系统中,而在陆地生态系统外源氮污染物较少的地区是否存在厌氧氨氧化过程且其在氮循环中发挥的作用,还很少有相关报道.本研究应用分子生物学技术研究了氮污染负荷较低的青藏高原地区不同海拔湿地和旱地土壤样品中厌氧氨氧化细菌的丰度及其生物多样性.结果表明,在青藏高原地区,普遍存在厌氧氨氧化细菌.使用厌氧氨氧化细菌特异性引物HSBeta396f/HSBeta742r进行定量发现,厌氧氨氧化细菌丰度随着海拔的升高而降低.垂向尺度上,海拔较低地区表层样品厌氧氨氧化细菌丰度高于底层样品,海拔较高地区则相反.通过构建厌氧氨氧化细菌系统发育分析发现,青藏高原地区厌氧氨氧化细菌的生物多样性较高,且多数可能属于新型厌氧氨氧化细菌.该区域湿地沉积物样品厌氧氨氧化细菌生物多样性明显低于旱地土壤样品.湿地沉积物样品厌氧氨氧化细菌生物多样性与海拔无明显关系,但旱地土壤样品厌氧氨氧化细菌生物多样性随着海拔的增高有上升趋势.     

哈尔滨市生物多样性保护工作研究

生物多样性是维持生态平衡、促进人与自然和谐发展的重要成分,保护生物多样性,对于人类经济和未来的发展都是极其有利的。文章是在总结哈尔滨市生物多样性保护工作的现状成效,分析存在的问题挑战,提出一些保护措施,意在提高人们生物多样性保护意识,切实改善生态环境。     

风景名胜区生物多样性保护的理论与实践——以黄山风景区为例

生物多样性是风景区重要的旅游资源以及环境资源，本文应用景观生态学原理及生物多样性保护的最新理论，探讨了生物多样性保护的方法，包括保护区面积的科学划分以及在面积不足时需要采取的生态学设计，并以黄山风景区为例，对这一理论及方法进行了论证。     

The Fat of the Land: Linking American Food Overconsumption, Obesity, and Biodiversity Loss

Americans’ excessive consumption of food harms their health and quality of life and also causes direct and indirect environmental degradation, through habitat loss and increased pollution from agricultural fertilizers and pesticides. We show here that reducing food consumption (and eating less meat) could improve Americans’ health and well-being while facilitating environmental benefits ranging from establishing new national parks and protected areas to allowing more earth-friendly farming and ranching techniques. We conclude by considering various public policy initiatives to lower per capita caloric intake and excessive meat consumption, and to translate this temperate behavior into substantial environmental protection.     

Effects of Liming and Ash Application on Below Ground Ectomycorrhizal Community Structure in Two Norway Spruce Forests

The effect of lime and ash additions upon the below ground ectomycorrhizal communities was studied at two spruce forest sites, Horröd and Hasslöv, in Southern Sweden. At Hasslöv, fifteen years after the addition of 8.75 ton ha^-1 of dolomite, the species richness of the mycorrhizal community was unchanged. However, the liming resulted in an almost total replacement of species normally found under the site conditions, with only three morphotypes from a total of 24 distinguished being common to both the control and limed plots. At Horröd, four years after the application of 3.25 ton ha^-1 crushed lime, there was a significant reduction in the number of species recorded. This was not a result of a reduction in root tips sampled, since there was no significant treatment effect upon root tip abundance. Instead, it appeared that the less common species present in the control plots had been lost following liming. At the same site, the addition of 4.28 ton ha^-1 of wood ash had little effect upon the mycorrhizal community as a whole, with only small changes recorded in the abundance of a small number of species. This study highlights the urgent need for additional data on the temporal and load response of ectomycorrhizal fungi to the addition of lime. This information is vital in view of the proposed widespread use of lime as a counter measure to soil acidification.