国产日韩欧美一区二区三区三州_亚洲少妇熟女av_久久久久亚洲av国产精品_波多野结衣网站一区二区_亚洲欧美色片在线91_国产亚洲精品精品国产优播av_日本一区二区三区波多野结衣 _久久国产av不卡

?

高被引論文摘要

2017-01-28 19:31:55
關(guān)鍵詞:生物多樣性長(zhǎng)白山自然保護(hù)區(qū)

歐陽(yáng)志云,王效科,苗鴻

高被引論文摘要

被引頻次:2083

中國(guó)陸地生態(tài)系統(tǒng)服務(wù)功能及其生態(tài)經(jīng)濟(jì)價(jià)值的初步研究

歐陽(yáng)志云,王效科,苗鴻

生態(tài)系統(tǒng)服務(wù)功能主要表現(xiàn)為提供保存生物進(jìn)化所需要的豐富的物種與遺傳資源,太陽(yáng)能,二氧化碳的固定,有機(jī)質(zhì)的合成,區(qū)域氣候調(diào)節(jié),維持水及營(yíng)養(yǎng)物質(zhì)的循環(huán),土壤的形成與保護(hù),污染物的吸收與降解及創(chuàng)造物種賴(lài)以生存與繁育的條件,維持整個(gè)大氣化學(xué)組分的平衡與穩(wěn)定,以及由于豐富的生物多樣性所形成的自然景觀及其具有的美學(xué)、文化、科學(xué)、教育的價(jià)值。生態(tài)系統(tǒng)的這些功能雖不表現(xiàn)為直接的生產(chǎn)與消費(fèi)價(jià)值,但它們是生物資源直接價(jià)值產(chǎn)生與形成的環(huán)境??梢哉f(shuō),正是生態(tài)系統(tǒng)的服務(wù)功能,才使人類(lèi)的生態(tài)環(huán)境條件得以維持和穩(wěn)定。從生態(tài)系統(tǒng)的服務(wù)功能著手,首先研究中國(guó)陸地生態(tài)系統(tǒng)在有機(jī)物質(zhì)的生產(chǎn)、CO2的固定、O2的釋放、重要污染物質(zhì)降解,以及在涵養(yǎng)水源、保護(hù)土壤中的生態(tài)功能作用,然后再運(yùn)用影子價(jià)格,替代工程或損益分析等方法探討了中國(guó)生態(tài)系統(tǒng)的間接經(jīng)濟(jì)價(jià)值。研究表明我國(guó)陸地生態(tài)系統(tǒng)具有巨大的生態(tài)經(jīng)濟(jì)效益,對(duì)維持我國(guó)社會(huì)經(jīng)濟(jì)的可持續(xù)發(fā)展具有不可替代的作用。

生態(tài)系統(tǒng)服務(wù)功能;生態(tài)經(jīng)濟(jì)價(jià)值

來(lái)源出版物:生態(tài)學(xué)報(bào), 1999, 19(5): 607-613

被引頻次:1252

長(zhǎng)白山自然保護(hù)區(qū)森林生態(tài)系統(tǒng)間接經(jīng)濟(jì)價(jià)值評(píng)估

薛達(dá)元,包浩生,李文華

摘要:使用市場(chǎng)價(jià)值法、影子工程法、機(jī)會(huì)成本法和替代花費(fèi)法等對(duì)長(zhǎng)白山自然保護(hù)區(qū)森林牛態(tài)系統(tǒng)的功能價(jià)值進(jìn)行了經(jīng)濟(jì)評(píng)估評(píng)價(jià)結(jié)果表明,保護(hù)區(qū)總的生態(tài)功能價(jià)值為176465.94萬(wàn)元,其中活立木生產(chǎn)量?jī)r(jià)值10777.43萬(wàn)元,涵養(yǎng)水源價(jià)值69741.2萬(wàn)元,保護(hù)土壤減少侵蝕的價(jià)值2307.02萬(wàn)元,固碳以減緩溫室效應(yīng)的價(jià)值87716.6萬(wàn)元,林分持留N、P、K分價(jià)值4338.88萬(wàn)元,降解SO2和防治病蟲(chóng)害價(jià)值158473萬(wàn)元。

關(guān)鍵詞:自然保護(hù)區(qū);森林生態(tài)系統(tǒng);生物多樣性;間接價(jià)值;長(zhǎng)白山

來(lái)源出版物:中國(guó)環(huán)境科學(xué), 1999, 19(3): 247-252

被引頻次:529

陸地植物群落物種多樣性的梯度變化特征

賀金生,陳偉烈

摘要:研究陸地植物群落物種多樣性隨環(huán)境因子及群落演替梯度的變化特征是揭示生物多樣性與生態(tài)因子相互關(guān)系的重要方面。根據(jù)近期國(guó)內(nèi)外的文獻(xiàn),綜述了這方面的研究進(jìn)展。隨緯度的降低,通常物種多樣性隨之增加;隨著水分梯度的變化,物種多樣性的變化有6種趨勢(shì);隨海拔高度的變化,物種多樣性有5種模式;隨土壤養(yǎng)分梯度的變化,表現(xiàn)出不同的規(guī)律;演替過(guò)程中物種多樣性的變化趨勢(shì)相似。關(guān)于植物群落物種多樣性梯度格局的機(jī)制有多種假說(shuō),但仍需進(jìn)一步研究。

關(guān)鍵詞:物種多樣性;緯度梯度;水分梯度;海拔梯度;養(yǎng)分梯度;演替梯度

來(lái)源出版物:生態(tài)學(xué)報(bào), 1997, 17(1): 91-98

被引頻次:469

景觀生態(tài)學(xué)與生物多樣性保護(hù)

李曉文,胡遠(yuǎn)滿,肖篤寧

摘要:景觀生態(tài)學(xué)的發(fā)展為生物多樣性保護(hù)提供了新理論、方法和技術(shù)手段。從景觀多樣性與遺傳多樣性、物種多樣性、生態(tài)系統(tǒng)多樣性各層次生物多樣性之間的相互關(guān)系及生物多樣性保護(hù)的景觀規(guī)劃等方面評(píng)述近年來(lái)景觀生態(tài)學(xué)應(yīng)用于生物多樣性保護(hù)的主要內(nèi)容及研究進(jìn)展,闡述了生物多樣性動(dòng)態(tài)及反饋、生物多樣性保護(hù)的地理途徑(GAP分析)、景觀生態(tài)安全格局、區(qū)域和大陸尺度的生態(tài)網(wǎng)絡(luò)等一些新的概念和方法。

關(guān)鍵詞:景觀生態(tài)學(xué);景觀多樣性;生物多樣性保護(hù);景觀規(guī)劃

來(lái)源出版物:生態(tài)學(xué)報(bào), 1999, 19(3): 399-407

被引頻次:428

干擾的類(lèi)型、特征及其生態(tài)學(xué)意義

陳利頂,傅伯杰

摘要:干擾是自然界中無(wú)時(shí)無(wú)處不在的一種現(xiàn)象,是在不同時(shí)空尺度上偶然發(fā)生的不可預(yù)知的事件,直接影響著生態(tài)系統(tǒng)的結(jié)構(gòu)和功能演替。根據(jù)不同分類(lèi)原則,干擾可以分為自然干擾和人為干擾;內(nèi)部干擾和外部干擾;物理干擾、化學(xué)干擾和生物干擾;局部干擾和跨邊界干擾。常見(jiàn)的干擾類(lèi)型包括火干擾、放牧、土壤物理干擾、土壤化學(xué)干擾、踐踏、外來(lái)種入侵、洪水泛濫、森林采伐、礦山開(kāi)發(fā)、道路建設(shè)和旅游等。干擾主要具有以下一些特點(diǎn):1)多重性;2)生態(tài)影響的相對(duì)性;3)明顯的尺度性;4)是對(duì)生態(tài)演替過(guò)程的再調(diào)節(jié);5)是自然生態(tài)系統(tǒng)中不協(xié)調(diào)的現(xiàn)象;6)時(shí)空尺度的廣泛性。干擾的一個(gè)突出作用是導(dǎo)致生態(tài)系統(tǒng)中各類(lèi)資源的改變和生態(tài)系統(tǒng)結(jié)構(gòu)的重組。干擾的生態(tài)環(huán)境影響有利有弊,不僅取決于干擾本身性質(zhì),還取決于干擾作用的客體。適度的干擾可以促進(jìn)生物多樣性和生物資源的保護(hù)。因此研究干擾的性質(zhì)、生態(tài)效應(yīng)、有利的適度規(guī)模以及與人類(lèi)活動(dòng)的關(guān)系具有重要意義。

關(guān)鍵詞:干擾;類(lèi)型;景觀異質(zhì)性;生物多樣性;生態(tài)學(xué)意義

來(lái)源出版物:生態(tài)學(xué)報(bào), 2000, 20(4): 581-586

被引頻次:380

區(qū)域生態(tài)安全格局:概念與理論基礎(chǔ)

馬克明,傅伯杰,黎曉亞,等

摘要:提出區(qū)域生態(tài)安全格局概念的提出,適應(yīng)了生態(tài)系統(tǒng)恢復(fù)和生物多樣性保護(hù)的發(fā)展需求。針對(duì)區(qū)域生態(tài)環(huán)境問(wèn)題,通過(guò)干擾排除以及空間格局規(guī)劃和管理,能夠保護(hù)和恢復(fù)生物多樣性,維持生態(tài)系統(tǒng)結(jié)構(gòu)、功能和過(guò)程的完整性,實(shí)現(xiàn)對(duì)區(qū)域生態(tài)環(huán)境問(wèn)題的有效控制和持續(xù)改善。區(qū)域生態(tài)安全格局的研究對(duì)象具有針對(duì)性、研究尺度具有區(qū)域性、研究問(wèn)題具有系統(tǒng)性、研究手段具有主動(dòng)性。它強(qiáng)調(diào)區(qū)域尺度的生物多樣性保護(hù)、退化生態(tài)系統(tǒng)恢復(fù)及其空間合理配置、生態(tài)系統(tǒng)健康的維持、景觀生態(tài)格局的優(yōu)化、以及對(duì)社會(huì)經(jīng)濟(jì)發(fā)展需求的滿足。它更加強(qiáng)調(diào)格局與過(guò)程安全及其整體集成,將生態(tài)系統(tǒng)管理對(duì)策落實(shí)到具體的空間地域上,實(shí)現(xiàn)管理效果的直觀可視。相關(guān)理論,景觀生態(tài)學(xué)、干擾生態(tài)學(xué)、保護(hù)生物學(xué)、恢復(fù)生態(tài)學(xué)、生態(tài)經(jīng)濟(jì)學(xué)、生態(tài)倫理學(xué)、和復(fù)合生態(tài)系統(tǒng)理論等為其提供了堅(jiān)實(shí)的理論基礎(chǔ)。區(qū)域生態(tài)安全格局不存在一個(gè)固定標(biāo)準(zhǔn),人類(lèi)對(duì)生態(tài)系統(tǒng)服務(wù)功能需求的不斷變化是生態(tài)系統(tǒng)管理的根本原因。實(shí)現(xiàn)區(qū)域生態(tài)安全不但要以社會(huì)、經(jīng)濟(jì)、文化、道德、法律、和法規(guī)為手段,更要以其不斷發(fā)展對(duì)生態(tài)系統(tǒng)服務(wù)功能的新需求為目標(biāo)逐步進(jìn)行。區(qū)域生態(tài)安全格局研究對(duì)于解決區(qū)域生態(tài)環(huán)境問(wèn)題具有不可替代的作用,具有廣闊應(yīng)用前景。

關(guān)鍵詞:區(qū)域生態(tài)安全格局;理論基礎(chǔ);生態(tài)恢復(fù);生物保護(hù);社會(huì)經(jīng)濟(jì)發(fā)展

來(lái)源出版物:生態(tài)學(xué)報(bào), 2004, 24(4): 761-768

被引頻次:330

多樣性指數(shù)在海洋浮游植物研究中的應(yīng)用

孫軍,劉東艷

摘要:對(duì)海洋浮游植物群落分析中常用的多樣性指數(shù)進(jìn)行了比較研究。對(duì)物種豐富度依賴(lài)型、豐度依賴(lài)型和實(shí)測(cè)浮游植物群落中物種豐富度、Shannon指數(shù)(以2或e為底)、Pielou均勻度指數(shù)、Simpson指數(shù)(1-D或1/D形式)、Margalef指數(shù)、Berger-Parker指數(shù)、McIntosh指數(shù)、McIntosh均勻度指數(shù)、Brillouin指數(shù)、Brillouin均勻度指數(shù)、Fisherα指數(shù)和Q統(tǒng)計(jì)指數(shù)等不同多樣性指數(shù)計(jì)算結(jié)果進(jìn)行了比較,發(fā)現(xiàn)不同多樣性指數(shù)對(duì)浮游植物群落多樣性的分析存在明顯差異。對(duì)于一般情況下浮游植物群落多樣性的研究,物種豐富度、Margalef指數(shù)、Fisherα指數(shù)、Shannon指數(shù)、Simpson相遇指數(shù)和Pielou指數(shù)的綜合使用是較合適的,但對(duì)Margalef指數(shù)和Fisherα指數(shù)的結(jié)果要謹(jǐn)慎解釋。并在綜合應(yīng)用各指數(shù)的基礎(chǔ)上提出了浮游植物群落多樣性分析的一般步驟。

關(guān)鍵詞:浮游植物;多樣性指數(shù);等級(jí)豐度作圖;生物多樣性

來(lái)源出版物:海洋學(xué)報(bào), 2004, 26(1): 62-75

被引頻次:276

土壤微生物多樣性影響因素及研究方法的現(xiàn)狀與展望

周桔,雷霆

摘要:土壤微生物是土壤生態(tài)系統(tǒng)的重要組成部分,在土壤有機(jī)物質(zhì)分解和養(yǎng)分釋放、能量轉(zhuǎn)移等生物地化循環(huán)中起著重要作用。隨著人們對(duì)生物多樣性重要性認(rèn)識(shí)的不斷深入及研究方法的不斷改進(jìn),土壤微生物多樣性,尤其是功能多樣性的研究工作逐漸受到生態(tài)學(xué)家的重視。本文從土壤微生物多樣性的影響因素以及研究方法等方面闡述了目前國(guó)內(nèi)外土壤微生物多樣性的研究現(xiàn)狀,并對(duì)其未來(lái)研究方向進(jìn)行了展望。

關(guān)鍵詞:生物多樣性;微生物;土壤

來(lái)源出版物:生物多樣性, 2007, 15(3): 306-311

被引頻次:255

植物物種多樣性的垂直分布格局

唐志堯,方精云

摘要:生物多樣性沿環(huán)境梯度的變化趨勢(shì)是生物多樣性研究的一個(gè)重要議題,而海拔梯度包含了多種環(huán)境因子的梯度效應(yīng),因此研究生物多樣性的海拔梯度格局對(duì)于揭示生物多樣性的環(huán)境梯度變化規(guī)律具有重要意義。在不同的研究尺度,植物多樣性沿海拔梯度具有不同的分布格局,而形成這種格局的因素有很大差異。本文從α多樣性,β多樣性和γ多樣性三個(gè)尺度總結(jié)了植物物種多樣性沿海拔梯度分布格局及其環(huán)境解釋。α多樣性沿海拔梯度的分布格局在不同生活型的物種之間差異很大,但對(duì)于木本植物來(lái)說(shuō),雖然也存在其他格局,但α多樣性隨海拔升高而降低是被廣泛接受的一種格局。在一般情況下,β多樣性隨著海拔的升高而降低,并且對(duì)于不同生活型的物種,β多樣性沿海拔梯度具有相似的分布格局。γ多樣性沿海拔梯度具有兩種分布格局:偏峰分布格局和顯著的負(fù)相關(guān)格局;特有物種數(shù)往往隨著海拔的升高而減少,而特有度則隨著海拔的升高而增加。

關(guān)鍵詞:物種多樣性;海拔梯度;α多樣性;β多樣性;γ多樣性

來(lái)源出版物:生物多樣性, 2008, 19(3): 702-715

被引頻次:247

生物多樣性科學(xué)前沿

陳靈芝,錢(qián)迎倩

摘要:由國(guó)際生物科學(xué)聯(lián)盟(IUBS)在1991年首先提出,至今已由其它5個(gè)重要國(guó)際組織或項(xiàng)目(SCOPE,UNESCO,ICSU,IGPB-GCTE及IUMS)共同主持的DIVERSITAS是迄今生物多樣性科學(xué)研究唯一的國(guó)際性項(xiàng)目。1996年7月,科學(xué)指導(dǎo)委員會(huì)草擬了本階段新的操作計(jì)劃,并于同年8月在IUBS執(zhí)行委員會(huì)上討論。操作計(jì)劃詳述了10個(gè)組成方面的內(nèi)容,其中5個(gè)為核心組成部分,其它5個(gè)為特別目標(biāo)研究領(lǐng)域(STARS)?!吧锒鄻有詫?duì)生態(tài)系統(tǒng)功能的作用”是最核心的組成方面,也是1991年提出的唯一的研究?jī)?nèi)容。生物多樣性的保護(hù),恢復(fù)和持續(xù)利用既是重要的研究?jī)?nèi)容又是研究所要達(dá)到的最后目的。特別目標(biāo)研究領(lǐng)域包括了土壤和沉積物、海洋、淡水和微生物生物多樣性等重要而過(guò)去未引起足夠重視的領(lǐng)域。DIVERSITAS的研究?jī)?nèi)容與《生物多樣性公約》中的有關(guān)條款十分吻合,說(shuō)明科學(xué)研究就是為履行《公約》服務(wù)的。明確研究的指導(dǎo)思想,按中國(guó)國(guó)情選擇好有代表性的優(yōu)先地區(qū)以及開(kāi)展國(guó)際合作,逐步與國(guó)際接軌是下一步開(kāi)展生物多樣性研究應(yīng)考慮到的幾個(gè)方面。

關(guān)鍵詞:DIVERSITAS;生物多樣性;生態(tài)系統(tǒng)功能;《生物多樣性公約》;優(yōu)先地區(qū)

來(lái)源出版物:生態(tài)學(xué)報(bào), 2007, 15(3): 306-311

被引頻次:8766

來(lái)源出版物:Ecology Letters, 2001, 4 (4): 379-391

被引頻次:2727

Effects of biodiversity on ecosystem functioning: A consensus of current knowledge

Hooper DU; Chapin FS; Ewel JJ; et al.

Abstract:Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth’s biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls. The scientific community has come to a broad consensus on many aspects of the relationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are structured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth’s ecosystems and the diverse biota they contain. Based on our review of the scientific literature, we are certain of the following conclusions: 1) Species’ functional characteristics strongly influence ecosystem properties. Functional characteristics operate in a variety of contexts, including effects of dominant species, keystone species’, ecological engineers, and interactions among species (e.g., competition, facilitation, mutualism, disease, and predation). Relative abundance alone is not always a good predictor of the ecosystem-level importance of a species, aseven relatively rare species (e.g., a keystone predator) can strongly influence pathways of energy and material flows. 2) Alteration of biota in ecosystems via species invasions and extinctions caused by human activities has altered ecosystem goods and services in many well-documented cases. Many of these changes are difficult, expensive, or impossible to reverse or fix with technological solutions. 3) The effects of species loss or changes in composition, and the mechanisms by which the effects manifest themselves, can differ among ecosystem properties, ecosystem types, and pathways of potential community change. 4) Some ecosystem properties are initially insensitive to species loss because (a) ecosystems may have multiple species that carry out similar functional roles, (b) some species may contribute relatively little to ecosystem properties, or (c) properties may be primarily controlled by abiotic environmental conditions. 5) More species are needed to insure a stable supply of ecosystem goods and services as spatial and temporal variability increases, which typically occurs as longer time periods and larger areas are considered. We have high confidence in the following conclusions: 1) Certain combinations of species are complementary in their patterns of resource use and can increase average rates of productivity and nutrient retention. At the same time, environmental conditions can influence the importance of complementarity in structuring communities. Identification of which and how many species act in a complementary way in complex communities is just beginning. 2) Susceptibility to invasion by exotic species is strongly influenced by species composition and, under similar environmental conditions, generally decreases with increasing species richness. However, several other factors, such as propagule pressure, disturbance regime, and resource availability also strongly influence invasion success and often override effects of species richness in comparisons across different sites or ecosystems. 3) Having a range of species that respond differently to different environmental perturbations can stabilize ecosystem process rates in response to disturbances and variation in abiotic conditions. Using practices that maintain a diversity of organisms of different functional effect and functional response types will help preserve a range of management options. Uncertainties remain and further research is necessary in the following areas: 1) Further resolution of the relationships among taxonomic diversity, functional diversity, and community structure is important for identifying mechanisms of biodiversity effects. 2) Multiple trophic levels are common to ecosystems but have been understudied in biodiversity/ ecosystem functioning research. The response of ecosystem properties to varying composition and diversity of consumer organisms is much more complex than responses seen in experiments that vary only the diversity of primary producers. 3) Theoretical work on stability has outpaced experimental, work, especially field research. We need long-term experiments to be able to assess temporal stability, as well as experimental perturbations to assess response to and recovery from a variety of disturbances. Design and analysis of such experiments must account for several factors that covary with species diversity. 4) Because biodiversity both responds to and influences ecosystem properties, understanding the feedbacks involved is necessary to integrate results from experimental communities with patterns seen at broader scales. Likely patterns of extinction and invasion need to be linked to different drivers of global change, the forces that structure communities, and controls on ecosystem properties for the development of effective management and conservation strategies. 5) This paper focuses primarily on terrestrial systems, with some coverage of freshwater systems, because that is where most empirical and theoretical study has focused. While the fundamental principles described here should apply to marine systems, further study of that realm is necessary. Despite some uncertainties about the mechanisms and circumstances under which diversity influences ecosystem properties, incorporating diversity effects into policy and management is essential, especially in making decisions involving large temporal and spatial scales. Sacrificing those aspects of ecosystems that are difficult or impossible to reconstruct, such as diversity, simply because we are not yet certain about the extent and mechanisms by which they affect ecosystem properties, will restrict future management options even further. It is incumbent upon ecologists to communicate this need, and the values that can derive from such a perspective, to those charged with economic and policy decision-making.

Keywords:biodiversity; complementary resource use; ecosystem goods and services; ecosystem processes; ecosystem properties; functional characteristics; functional diversity; net primary production; sampling effect; species extinction; species invasions; species richness; stability

來(lái)源出版物:Ecological Monographs, 2005, 75 (1): 3-35

被引頻次:2409

Effects of habitat fragmentation on biodiversity

Fahrig, L

Abstract:The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, drawing different conclusions regarding both the magnitude and direction of its effects. Habitat fragmentation is usually defined as a landscapescale process involving both habitat loss and the breaking apart of habitat. Results of empirical studies of habitat fragmentation are often difficult to interpret because (a) many researchers measure fragmentation at the patch scale, not the landscape scale and (b) most researchers measure fragmentation in ways that do not distinguish between habitat loss and habitat fragmentation per se, i.e., the breaking apart of habitat after controlling for habitat loss. Empirical studies to date suggest that habitat loss has large, consistently negative effects on biodiversity. Habitat fragmentation per se has much weaker effects on biodiversity that are at least as likely to be positive as negative. Therefore, to correctly interpret the influence of habitat fragmentation on biodiversity, the effects of these two components of fragmentation must be measured independently. More studies of the independent effects of habitat loss and fragmentation per se are needed to determine the factors that lead to positive versus negative effects of fragmentation per se. I suggest that the term“fragmentation” should be reserved for the breaking apart of habitat, independent of habitat loss.

來(lái)源出版物:Annual Review of Ecology Evolution and Systematics, 2003, 34: 487-515

被引頻次:2154

Routing security in wireless ad hoc networks

Colwell, RK; Coddington, JA

Abstract:Both the magnitude and the urgency of the task of assessing global biodiversity require that we make the most of what we know through the use of estimation and extrapolation. Likewise, future biodiversity inventories need to be designed around the use of effective sampling and estimation procedures, especially for ‘hyperdiverse’groups of terrestrial organisms, such as arthropods, nematodes, fungi, and microorganisms. The challenge of estimating patterns of species richness from samples can be separated into (i) the problem of estimating local species richness, and (ii) the problem of estimating the distinctness, or complementarity, of species assemblages. These concepts apply on a wide range of spatial, temporal, and functional scales. Local richness can be estimated by extrapolating species accumulation curves, fitting parametric distributions of relative abundance, or using non-parametric techniques based on the distribution of individuals among species or of species among samples. We present several of these methods and examine their effectiveness for an example data set. We present a simple measure of complementarity, with some biogeographic examples, and outline the difficult problem of estimating complementarity from samples. Finally, we discuss the importance of using 'reference' sites (or sub-sites) to assess the true richness and composition of species assemblages, to measure ecologically significant ratios between unrelated taxa, to measure taxon/sub-taxon (hierarchical) ratios, and to ‘calibrate’ standardized sampling methods. This information can then be applied to the rapid, approximate assessment of species richness and faunal or floral composition at ‘comparative’ sites.

來(lái)源出版物:Philosophical Transactions of the Royal Society of London Series B-Biological Sciences, 1994, 345 (1311): 101-118

被引頻次:1902

Mechanisms of maintenance of species diversity

Chesson, P

Abstract:The focus of most ideas on diversity maintenance is species coexistence, which may be stable or unstable, Stable coexistence can be quantified by the long-term rates at which community members recover from low density. Quantification shows that coexistence mechanisms function in two major ways: They may be (a) equalizing because they tend to minimize average fitness differences between species, or (b) stabilizing because they tend to increase negative intraspecific interactions relative to negative interspecific interactions. Stabilizing mechanisms are essential for species coexistence and include traditional mechanisms such as resource partitioning and frequencydependent predation, as well as mechanisms that depend on fluctuations in population densities and environmental factors in space and time. Equalizing mechanisms contribute to stable coexistence because they reduce large average fitness inequalities which might negate the effects of stabilizing mechanisms. Models of unstable coexitence, in which species diversity slowly decays over time, have focused almost exclusively on equalizing mechanisms. These models would be more robust if they also includedstabilizing mechanisms, which arise in many and varied ways but need not be adequate for full stability of a system. Models of unstable coexistence invite a broader view of diversity maintenance incorporating species turnover.

Keywords:coexistence; competition; predation; niche; spatial and temporal variation

來(lái)源出版物:Annual Review of Ecology and Systematics, 2000, 31: 343-366

被引頻次:1743

Ecology-biodiversity and ecosystem functioning: Current knowledge and future challenges

Loreau, M; Naeem S; Inchausti P; et al.

Abstract:The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels and generalize across ecosystem types and processes. Larger numbers of species are probably needed to reduce temporal variability in ecosystem processes in changing environments. A major future challenge is to determine how biodiversity dynamics, ecosystem processes, and abiotic factors interact.

來(lái)源出版物:Science, 2001 294 (5543): 804-808

被引頻次:1563

Emerging infectious diseases of wildlife: Threats to biodiversity and human health

Daszak, P; Cunningham, AA

Abstract:Emerging infectious diseases (EIDs) of free-living wild animals can be classified into three major groups on the basis of key epizootiological criteria: (i) EIDs associated with “spill-over” from domestic animals to wildlife populations living in proximity; (ii) EIDs related directly to human intervention, via host or parasite translocations; and (iii) EIDs with no overt human or domestic animal involvement. These phenomena have two major biological implications: first, many wildlife species are reservoirs of pathogens that threaten domestic animal and human health; second, wildlife EIDs pose a substantial threat to the conservation of global biodiversity.

Keywords:Attestation; public key infrastructure (PKI); Supervisory Control And Data Acquisition (SCADA); security; smart grid; trusted computing

來(lái)源出版物:Science, 2000, 287(5452): 443-449

被引頻次:1535

Impacts of biodiversity loss on ocean ecosystem services

Worm, Boris; Barbier, Edward B.; Beaumont, Nicola; et al.

Abstract:Human-dominated marine ecosystems are experiencing accelerating loss of populations and species, with largely unknown consequences. We analyzed local experiments, long-term regional time series, and global fisheries data to test how biodiversity loss affects marine ecosystem services across temporal and spatial scales. Overall, rates of resource collapse increased and recovery potential, stability, and water quality decreased exponentially with declining diversity. Restoration of biodiversity, in contrast, increased productivity fourfold and decreased variability by 21%, on average. We conclude that marine biodiversity loss is increasingly impairing the ocean’s capacity to provide food, maintain water quality, and recover from perturbations. Yet available data suggest that at this point, these trends are still reversible.

來(lái)源出版物:Science, 2006, 314(5800): 787-790

Biodiversity loss and its impact on humanity

Cardinale, Bradley J.; Duffy, J. Emmett; Gonzalez,Andrew; et al.

The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists and fungi inhabit the Earth. So, too, do 7 billion people. Two decades ago, at the first Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper.來(lái)源出版物:Nature, 2012 486 (7401): 59-67被引頻次:3195Biodiversity:Global biodiversity scenarios for the year 2100Sala, OE; Chapin FS; Armesto JJ; et al.Abstract:Scenarios of changes in biodiversity for the year 2100 can now be developed based on scenarios of changes in atmospheric carbon dioxide, climate, vegetation, and Land use and the known sensitivity of biodiversity to these changes. This study identified a ranking of the importance of drivers of change, a ranking of the biomes with respect to expected changes, and the major sources of uncertainties. For terrestrial ecosystems, land-use change probably will have the largest effect, followed by climate change, nitrogen deposition, biotic exchange, and elevated carbon dioxide concentration. For freshwater ecosystems, biotic exchange is much more important. Mediterranean climate and grassland ecosystems likely will experience the greatest proportional change in biodiversity because of thesubstantial influence of all drivers of biodiversity change. Northern temperate ecosystems are estimated to experience the least biodiversity change because major land-use change has already occurred. Plausible changes in biodiversity in other biomes depend on interactions among the causes of biodiversity change. These interactions represent one of the largest uncertainties in projections of future biodiversity change.來(lái)源出版物:Science, 2000, 287 (5459): 1770-1774被引頻次:2805Quantifying biodiversity: Procedures and pitfalls in the measurement and comparison of species richnessGotelli, NJ; Colwell RKAbstract:Species richness is a fundamental measurement of community and regional diversity, and it underlies many ecological models and conservation strategies. In spite of its importance, ecologists have not always appreciated the effects of abundance and sampling effort on richness measures and comparisons. We survey a series of common pitfalls in quantifying and comparing taxon richness. These pitfalls can be largely avoided by using accumulation and rarefaction curves, which may be based on either individuals or samples. These taxon sampling curves contain the basic information for valid richness comparisons, including category-subcategory ratios (species-to-genus and species-to-individual ratios). Rarefaction methods-both sample-based and individualbased-allow for meaningful standardization and comparison of datasets. Standardizing data sets by area or sampling effort may produce very different results compared to standardizing by number of individuals collected, and it is not always clear which measure of diversity is more appropriate. Asymptotic richness estimators provide lower-bound estimates for taxon-rich groups such as tropical arthropods, in which observed richness rarely reaches an asymptote, despite intensive sampling. Recent examples of diversity studies of tropical trees, stream invertebrates, and herbaceous plants emphasize the importance of carefully quantifying species richness using taxon sampling curves.

species richness; species density; taxon sampling; taxonomic ratios; biodiversity; rarefaction; accumulation curves; asymptotic richness; richness estimation; category-subcategory ratios

猜你喜歡
生物多樣性長(zhǎng)白山自然保護(hù)區(qū)
七姊妹山國(guó)家級(jí)自然保護(hù)區(qū)
漫步四季,探索不一樣的長(zhǎng)白山
長(zhǎng)白山冊(cè)封始于金代
關(guān)于濕地生物多樣性保護(hù)措施的探討
新疆夏爾希里自然保護(hù)區(qū)資源的保護(hù)研究利用
關(guān)于城市綠化建設(shè)中增加生物多樣性
利用生物多樣性防治園林植物病害的可行性分析
保護(hù)自然保護(hù)區(qū)刻不容緩
淺淡黃崗梁自然保護(hù)區(qū)的資源保護(hù)與開(kāi)發(fā)利用
嵐霧情吻長(zhǎng)白山
邹平县| 长治市| 石狮市| 衡山县| 利辛县| 留坝县| 确山县| 丽江市| 龙井市| 延川县| 临颍县| 博白县| 普定县| 九寨沟县| 安国市| 时尚| 新闻| 白山市| 阳春市| 石棉县| 清新县| 荣成市| 黄石市| 上饶市| 汪清县| 搜索| 双柏县| 台前县| 行唐县| 曲水县| 柳河县| 石屏县| 永安市| 砚山县| 滦平县| 宝丰县| 泽库县| 鹿泉市| 祁连县| 开阳县| 湛江市|