A robust nonparametric method for quantifying undetected extinctions

How many species have gone extinct in modern times before being described by science? To answer this question, and thereby get a full assessment of humanity's impact on biodiversity, statistical methods that quantify undetected extinctions are required. Such methods have been developed recently, but they are limited by their reliance on parametric assumptions; specifically, they assume the pools of extant and undetected species decay exponentially, whereas real detection rates vary temporally with survey effort and real extinction rates vary with the waxing and waning of threatening processes. We devised a new, nonparametric method for estimating undetected extinctions. As inputs, the method requires only the first and last date at which each species in an ensemble was recorded. As outputs, the method provides estimates of the proportion of species that have gone extinct, detected, or undetected and, in the special case where the number of undetected extant species in the present day is assumed close to zero, of the absolute number of undetected extinct species. The main assumption of the method is that the per‐species extinction rate is independent of whether a species has been detected or not. We applied the method to the resident native bird fauna of Singapore. Of 195 recorded species, 58 (29.7%) have gone extinct in the last 200 years. Our method projected that an additional 9.6 species (95% CI 3.4, 19.8) have gone extinct without first being recorded, implying a true extinction rate of 33.0% (95% CI 31.0%, 36.2%). We provide R code for implementing our method. Because our method does not depend on strong assumptions, we expect it to be broadly useful for quantifying undetected extinctions.     

铁岭市莲花湖湿地生物多样性评价研究

在对莲花湖湿地物种现状进行调查分析、监测及统计的基础上,建立湿地生物多样性评价指标体系与赋值标准,从物种丰富度、生态系统类型多样性、物种特有性、外来物种入侵度四个一级指标及十五个二级指标对莲花湖湿地生物多样性进行了评价。莲花湖湿地生物多样性总评分为67分,结果表明莲花湖湿地生物多样性处于优秀水平,应继续加强对莲花湖湿地生态环境的恢复和管理。研究结果将为相关管理部门提供决策依据,为莲花湖湿地生物多样性的保护和管理打下基础。     

The plant-enhanced bio-cathode: Root exudates and microbial community for nitrogen removal

A plant bio-electrochemical system(PBES) was constructed for organic pollutant removal and power generation. The bio-cathode, composed of granular activated carbon(GAC), stainless wire mesh and a plant species(Triticum aestivum L.), was able to catalyze cathodic reactions without any requirement for aeration or power input. During the 60-day-long operation, an average voltage of 516 m V(1000 Ω) and maximum power density(Pmax) of 0.83 W/m~3 were obtained in the PBES. The total nitrogen removal and total organic carbon removal in the PBES were 85% and 97%, respectively. Microbial community analyses indicated that bacteria associated with power generation and organic removal were the predominant species in the bio-cathode, and plant-growth-promoting rhizobacteria were also found in the PBES. The results suggested that the coupling of plants with the GAC cathode may enhance the organicmatter degradation and energy generation from wastewater and therefore provide a new method for bio-cathode design and promote energy efficiency.     

寒冷地区滨岸缓冲带植物筛选

为在寒冷地区建立高效的滨岸缓冲带水体工程,选择早熟禾、高羊茅、3种本地耐寒性植物,研究剪股颖构建河流滨岸缓冲带植物的经济性、生长特性、光合作用及其对悬浮物、氮、磷的净化能力。结果表明,3种植物在经济性方面高羊茅与早熟禾差别不大,远低于剪股颖;在生长特性方面,早熟禾与高羊茅的表现相近,高羊茅略好,但比剪股颖表现优秀,早熟禾在净光合作用速率、蒸腾速率以及水分利用效率方面比高羊茅及剪股颖出色;在面源污染物去除率方面,地表径流悬浮物的去除中,早熟禾表现突出;在溶解性磷与总氮的净化中,3种植物表现差异不大,早熟禾略有优势。综合比较各项指标,早熟禾可作为寒冷地区构建滨岸缓冲带较为理想的备选植物。     

滇金丝猴栖息地生物多样性及其威胁因素研究

滇金丝猴栖息地是我国生物多样性保护关键区域之一，具有生态系统多样性、物种多样性、遗传多样性等特点。分析了滇金丝猴栖息地目前受到的威胁，提出了今后保护管理的意见。     

中国自然保护区对生物多样性保护的贡献

自然保护区建设是保护生物多样性的最有效途径。至１９９３年底，我国共建立各类型自然保护区７６３个，总面积６６１．８万ｈｍ２，约占国土面积的６．８％。本文在总结我国自然保护区建设成就的基础上，概述了自然保护区对各类自然生态系统、野生生物、驯化物种、野生亲缘种及种质资源保护的现状，包括为保护生物多样性各组分已建自然保护区的数量、面积、分布及管理；评价了自然保护区对生物多样性各组分保护的效果；分析了存在问题并提出加强生物多样性就地保护的措施。     

植物净化空气中汞污染的研究

对上海市常见易生长的22种植物进行了现场采样测试，结果发现，瓜子黄杨、广玉兰、海桐、蚊母、墨西哥落叶杉及棕榈对汞蒸气具有很强的吸收富集能力及抗毒性能．然后采用富集能力最强的瓜子黄杨进行一系列试验，结果显示，汞浓度随接触瓜子黄杨时间的延长而降低，而瓜子黄杨叶片的汞含量随时间的延长而增加。根据吸汞实验，计算得瓜子黄杨叶面积的吸气速率为0.133m     

二氧化硫对植物生理生化的影响

通过对北方地区常见草坪品种———阿尔冈金、可奇思、猎狗、派尼等进行SO2 静态熏气处理,然后采用生理生化方法测定不同品种草坪在不同熏气浓度(浓度分别为大气中浓度的10 倍、20 倍、30 倍、40 倍)下体内生理生化指标———过氧化物酶(POD)、超氧化物歧化酶(SOD)、抗坏血酸氧化酶(ASO)、多酚氧化酶(PPO)等酶活力的变化,进而挑选出对SO2具有抗性的品种。     

生物多样性在路域植被养护中的应用

公路路域植被进入养护期以后，管护的经费开始减少，而植物演化刚刚开始，如还是按照原来的管护方式，势必造成植物群落的逆向演替，使其有可能再次回到裸露状态。因此，需要从生态学的原理出发，利用生物多样性对现有的群落进行改造，使其形成一个结构合理、稳定、防护效果突出的植物群落。     

矿区生态重建中生物多样性与可持续发展

复合生态系统受自然、经济、社会三方面的影响，是在生态工程控制下的生态系统，其生物多样性也受生态工程的控制。本文以安太堡露天煤矿为例，讨论了复合生态系统生物多样性与可持续发展的关系。说明复合生态系统的生物多样性要求经济，生态，社会综合效益最佳，其建设必须以生境建设为基础，并以生态工程手段保持和调节植被结构，以使矿区得到真正可持续发展。