“整合物种概念”和“分化路上的物种”

已有的各个物种概念对物种的认识类似盲人摸象, 只包含了物种的某一个方面; 而一个分化后期的成熟物种应涵盖了所有的物种概念。但是, 尚未到达分化后期的物种往往又已开始新一轮的物种分化; 自然中存在的多数“物种”处于分化路上。这种循环往复连续分化产生的物种, 存在种间生殖隔离不彻底、基因流频繁发生、网状进化突出等现象。此外, 对于不同的物种对, 最早开始分化的基因以及不同物种概念所要求的条件的分化顺序不是统一的, 而是随机的。定义一个适合所有“分化路上的物种”概念存在较大困难。但是, 应采用尽可能多的物种概念来界定分化路上的物种、发表新种和进行分类处理; 也应承认种间可能广泛存在不完全的生殖隔离和有限的基因流, 即有不属于两个物种群体的杂交或回交个体的存在。这样划分的物种比只依据一个物种概念认定的物种具有更高的客观性和科学性。     

“地衣”词考

本文考证了中国先秦时期到清末古籍中对“地衣”的解释;其中有共生学意义的“地衣”一词,是在清代李善兰的《植物学》一书中被提出的。     

“超级真菌”耳念珠菌研究进展

耳念珠菌Candida auris也被称为“超级真菌”,是近年来出现的一种人体病原真菌新物种,临床分离株通常具有多重耐药和高致死率等特征。2009年日本首次报道耳念珠菌之后,其感染病例在多个国家呈现出爆发式增长。目前已报道的病例分布在全球五大洲27个国家,包括中国。耳念珠菌感染给临床诊断和防控以及人类健康带来了巨大的挑战。本文从该菌临床分离菌株的生物学、遗传变异分化及耐药特征等方面入手,围绕分子流行病学、基因组特征、毒性因子和耐药性等方面系统地综述了近年来国内外取得的相关进展,并探讨了我国耳念珠菌感染的诊断、治疗和预防的措施。     

“2020年后全球生物多样性框架”的谈判进展以及对我国的建议

“2020年后全球生物多样性框架”是当前《生物多样性公约》谈判的焦点议题, 了解该议题的谈判进展将对我国顺利举办第15次缔约方大会(COP15)产生积极的作用。本文在梳理相关谈判进程的基础上, 分析了各方主要观点, 并就我国应对国际谈判并以东道国身份推进该框架的制定进程提出了建议。各方对制定框架的时间表、程序和一般性原则形成了较为一致的共识, 认为应尽快确定“2020年后全球生物多样性框架”的程序及时间表, 基于“爱知生物多样性目标”的执行经验、科学结论和和广泛的信息来源, 与“可持续发展目标”及其他国际进程衔接, 重视利用情景和模型, 并支持更多利益相关方参与制定过程。同时, 各方认为框架应主要包括土地利用、保护和恢复生物多样性的措施、解决生物多样性丧失的根本原因、主流化、能力建设、资源调动、国家承诺等要素。为应对国际谈判, 建议我国在《公约》谈判会议中适时提出以下观点: 重视实现可持续利用相关的目标; 提升评估指标体系的合理性; 科学制定措施。此外, 建议我国采取以下措施积极推进框架制定进程: 充分利用国际高级别会议, 提升政治重视程度; 积极与主要国际进程协作, 推进该框架深入讨论; 重视调动利益相关方积极性。     

干旱、半干旱区生态学学术讨论会在乌鲁木齐举行

中国生态学会主持召开的“干旱、半干旱区生态学学术讨论会”于1982年10月6日至11日在新疆维吾尔自治区乌鲁木齐市举行,参加这次学术讨论会的有来自西北五省(区)(新疆、青海、甘肃、宁夏、陕西)以及内蒙古、山西、河北、北京、沈阳、上海、南京、云南等13省(区)市的70个单位的87名代表。包括动植物生态、农、林、牧、水利、气象、环保等专业。共收到论文48篇。会议分两个阶段进行。第一阶段(6日上午至8日上午)大会学术报告。有24位代表做了报告,包括动物生态、植物生态(广义)、生态平衡、人口、农业、环境保护等方面。植物生态方面有分析生态因素对作物的影响,探讨增产途径的,如陈培元(中国科学院西北水保所)的“黄土高原半干旱地区旱地小麦水分利用效率和抗旱增产途径问题”,周电辉(甘     

Biodiversity and the Heterogeneous Disturbance Regime on Military Training Lands

Disproportionately large numbers of threatened and endangered species and unusually high biodiversity occur on active and former military training areas. Although this may seem paradoxical given the apparently destructive nature of military training, an evaluation of the nature and extent of the disturbances is enlightening. Military training frequently produces heterogeneous landscapes. Large portions of military training areas remain virtually untouched, favoring disturbance‐averse species; other portions are heavily disturbed, favoring disturbance‐dependent species. The rich habitat mosaics include the two extremes as well as the continua of disturbance and succession between them, thus providing suitable habitat for a very large number of species with widely varying habitat requirements. To explain the phenomenon, a heterogeneous disturbance hypothesis is proposed which suggests that biodiversity is maximized where multiple kinds, frequencies, severities, periodicities, sizes, shapes, and/or durations of disturbance occur concomitantly on a landscape in a spatially and temporally distributed fashion. The enhanced biodiversity occurring on active and former military training areas illustrates the need for restoration ecologists to restore or maintain an appropriate heterogeneous disturbance regime when attempting to restore ecosystem function and biodiversity.     

乌鲁木齐市园林春秋季鸟类群落多样性

2011年4～5月、10～11月,用样线法对乌鲁木齐市中心城区5个园林鸟类群落的组成和多样性进行了调查,共记录到鸟类47种,隶属于9目23科,分布型以古北界为主。其中留鸟、夏候鸟和冬候鸟分别占鸟类总种数的44.68%、34.04%和10.64%,鸟类群落优势种为[树]麻雀Passer montanus、家麻雀Passer domesticus和乌鸫Turdus merula。园林鸟类的平均密度为(11.27±4.3)只/hm2(±S.D.),春季鸟类密度高于秋季,但二者差异不显著(F=0.002,P=0.194)。春季鸟类群落拥有较高物种丰富度和多样性,夏候鸟是此时鸟类群落的重要组成部分;秋季鸟类群落的多样性低而优势度较高,冬候鸟对群落结构影响不大。各园林样地记录到的鸟类种数和密度差异较为明显,园林的内部生境多样性与鸟类种数呈正相关(R=0.9,P=0.037)。     

Environmental Productivity and Biodiversity Effects on Invertebrate Community Invasibility

Productivity influences the availability of resources for colonizing species. Biodiversity may also influence invasibility of communities because of more complete use of resource types with increasing species richness. We hypothesized that communities with higher environmental productivity and lower species richness should be more invasible by a competitor than those where productivity is low or where richness is high. We experimentally examined the invasion resistance of herbivorous meiofauna of Jamaican rock pools by a competitor crustacean (Ostracoda: Potamocypris sp. (Brady)) by contrasting three levels of nutrient input and four levels of species richness. Although relative abundance (dominance) of the invasive was largely unaffected by resource availability, increasing resources did increase the success rate of establishment. Effects of species richness on dominance were more pronounced with a trend towards the lowest species richness treatment of 2 resident species being more invasible than those with 4, 6, or 7 species. These results can be attributed to a ‘sampling effect associated with the introduction of Alona davidii (Richard) into the higher biodiversity treatments. Alona dominated the communities where it established and precluded dominance by the introduced ostracod. Our experimental study supports the idea that niche availability and community interactions define community invasibility and does not support the application of a neutral community model for local food web management where predictions of exotic species impacts are needed.     

Impact of Fertilizing Pattern on the Biodiversity of a Weed Community and Wheat Growth

Weeding and fertilization are important farming practices. Integrated weed management should protect or improve the biodiversity of farmland weed communities for a better ecological environment with not only increased crop yield, but also reduced use of herbicides. This study hypothesized that appropriate fertilization would benefit both crop growth and the biodiversity of farmland weed communities. To study the effects of different fertilizing patterns on the biodiversity of a farmland weed community and their adaptive mechanisms, indices of species diversity and responses of weed species and wheat were investigated in a 17-year field trial with a winter wheat-soybean rotation. This long term field trial includes six fertilizing treatments with different N, P and K application rates. The results indicated that wheat and the four prevalent weed species (Galium aparine, Vicia sativa, Veronica persica and Geranium carolinianum) showed different responses to fertilizer treatment in terms of density, plant height, shoot biomass, and nutrient accumulations. Each individual weed population exhibited its own adaptive mechanisms, such as increased internode length for growth advantages and increased light interception. The PK treatment had higher density, shoot biomass, Shannon-Wiener and Pielou Indices of weed community than N plus P fertilizer treatments. The N1/2PK treatment showed the same weed species number as the PK treatment. It also showed higher Shannon-Wiener and Pielou Indices of the weed community, although it had a lower wheat yield than the NPK treatment. The negative effects of the N1/2PK treatment on wheat yield could be balanced by the simultaneous positive effects on weed communities, which are intermediate in terms of the effects on wheat and weeds.     

Conserving Biodiversity in a Human-Dominated World: Degradation of Marine Sessile Communities within a Protected Area with Conflicting Human Uses

Conservation research aims at understanding whether present protection schemes are adequate for the maintenance of ecosystems structure and function across time. We evaluated long-term variation in rocky reef communities by comparing sites surveyed in 1993 and again in 2008. This research took place in Tigullio Gulf, an emblematic case study where various conservation measures, including a marine protected area, have been implemented to manage multiple human uses. Contrary to our prediction that protection should have favored ecosystem stability, we found that communities subjected to conservation measures (especially within the marine protected area) exhibited the greatest variation toward architectural complexity loss. Between 1993 and 2008, chronic anthropogenic pressures (especially organic load) that had already altered unprotected sites in 1993 expanded their influence into protected areas. This expansion of human pressure likely explains our observed changes in the benthic communities. Our results suggest that adaptive ecosystem-based management (EBM), that is management taking into account human interactions, informed by continuous monitoring, is needed in order to attempt reversing the current trend towards less architecturally complex communities. Protected areas are not sufficient to stop ecosystem alteration by pressures coming from outside. Monitoring, and consequent management actions, should therefore extend to cover the relevant scales of those pressures.     

The Western Ordos Plateau as a Biodiversity Center of Relic Shrubs in Arid Areas of China

The western Ordos plateau in the central-north of China is abundant in relic shrub species. Totally 54 shrub species belonging to 31 genera in 16 families are found in 10 desert shrub communities,including 10 local endemic species, five relic shrub species, and seven threatened species defined by the China Red Data Book. The percentage of the threatened shrub species to the total is as high as 12.9%, much greater than the national average (3.5%). Although a National Natural Reserve has been established since 1998 in the western Ordos plateau, the exploitation of mining resources continues to expand at a significant biological cost. Given the circumstances, future conservation efforts should focus on (1) removing coking and cement facilities from the reserve; (2) defining the boundaries of the Western Ordos National Natural Reserve encompassing all habitats where these shrub species occur; (3) implementing comprehensive plans coupling conservation with economic development; (4) enforcing ecological restoration after mining; and (5)␣establishing comprehensive population monitoring systems and promoting ex situ conservation. In addition, two local endemic relic species (Tetraena mongolica and Helianthemum ordosicum), which were defined as rare species in the second conservation priority by the China Red Data Book, should be considered as endangered species in the first conservation priority rank due to the extremely restricted distribution ranges, extremely scarce populations and more prominently, the currently increasing human disturbances caused by mining and urbanization in the core conservation area of the western Ordos plateau.     

Environmental Factors Affecting the Diversity and Abundance of Soil Photomicrobes in Arid Lands of Subtropical Taiwan

The purpose of this study was to characterize the diversity and abundance of indigenous soil photomicrobes with respect to the physico-chemical environment at a highly eroded loamy sand mountain situated in mid-Taiwan. Denaturing gradient gel electrophoresis and clone library were employed to characterize the operational taxonomic unit of photomicrobes present in the natural environment. The predominant species identified by plastid 23S rRNA were green algae belonging to the genera Bracteacoccus, Coccomyxa, and Koliella, while sub-dominant species included the cyanobacteria Leptolyngbya and Microcoleus. Principal component analysis indicated that the distribution of soil photomicrobes exhibited a strong dependency on the chemical variables, such as organic materials, total nitrogen, and inorganic nutrients, and that the low diversity was related to low water potential status. The present study illustrated the main factors affecting the distribution of soil photomicrobes and provided the basic characteristics of biological soil crusts in arid lands in subtropical areas.     

Evolution of the Life Forms of Flowering Plants in a Biodiversity Formation

Biology Bulletin - The biomorphological diversity of riverside and aquatic herbaceous plants represented mainly by annual and biennial plants of vegetative origin, which replace perennial and...