Rahmati, M., Or, D., Amelung, W. et al. Soil is a living archive of the Earth system. Nat Rev Earth Environ (2023). https:///10.1038/s43017-023-00454-5

生態(tài)系統(tǒng)生態(tài)學(xué)是生態(tài)學(xué)的一個(gè)分支學(xué)科,，專注于研究生物體和它們在特定生態(tài)系統(tǒng)中的物理環(huán)境之間的相互作用。生態(tài)系統(tǒng)生態(tài)學(xué)研究能量和營養(yǎng)物質(zhì)在生態(tài)系統(tǒng)中的流動(dòng),、生態(tài)系統(tǒng)內(nèi)不同物種之間的關(guān)系,，以及生態(tài)系統(tǒng)如何應(yīng)對長期以來的環(huán)境變化。生態(tài)系統(tǒng)生態(tài)學(xué)旨在了解生態(tài)系統(tǒng)中存在的復(fù)雜關(guān)系和反饋循環(huán),，以及它們?nèi)绾未龠M(jìn)生態(tài)系統(tǒng)的功能和穩(wěn)定,。通過研究生態(tài)系統(tǒng)的結(jié)構(gòu)和功能，生態(tài)系統(tǒng)生態(tài)學(xué)家可以深入了解生態(tài)系統(tǒng)如何受到自然和人為干擾的影響,，如氣候變化,，污染和棲息地破壞。生態(tài)系統(tǒng)生態(tài)學(xué)是一個(gè)高度跨學(xué)科的領(lǐng)域,，吸收了來自生物學(xué),、地質(zhì)學(xué)、化學(xué),、物理學(xué)和數(shù)學(xué)的概念和技術(shù),。生態(tài)系統(tǒng)生態(tài)學(xué)的最終目標(biāo)是提供對生態(tài)系統(tǒng)如何工作的全面理解，并為旨在保護(hù)這些重要自然系統(tǒng)的管理和保護(hù)工作提供信息,。全球氣候變化是我們這個(gè)時(shí)代最緊迫的環(huán)境問題之一,，因此在生態(tài)系統(tǒng)生態(tài)學(xué)中有幾個(gè)熱門話題與之相關(guān)。其中一些主題包括: 變暖溫度對生態(tài)系統(tǒng)過程的影響: 隨著溫度繼續(xù)上升,，生態(tài)系統(tǒng)過程，如光合作用,，呼吸和養(yǎng)分循環(huán)正在受到影響,。研究人員正在研究生態(tài)系統(tǒng)過程中的這些變化將如何影響生態(tài)系統(tǒng)的功能和服務(wù),。物種分布范圍和群落動(dòng)態(tài)的變化: 隨著氣溫的升高，許多物種的分布范圍會(huì)隨著氣候條件的變化而變化,。生態(tài)系統(tǒng)生態(tài)學(xué)家正在研究這些變化是如何影響物種相互作用和群落動(dòng)態(tài)的,。碳循環(huán)反饋: 生態(tài)系統(tǒng)在全球碳循環(huán)中發(fā)揮著至關(guān)重要的作用，氣候變化引起的生態(tài)系統(tǒng)進(jìn)程變化正在影響生態(tài)系統(tǒng)可以儲(chǔ)存的碳量,。研究人員正在研究這些變化將如何反饋到氣候系統(tǒng),，潛在地加劇氣候變化。極端天氣事件的影響: 氣候變化導(dǎo)致更頻繁和更強(qiáng)烈的極端天氣事件,，如干旱,、洪水和野火。生態(tài)系統(tǒng)生態(tài)學(xué)家正在研究這些事件是如何影響生態(tài)系統(tǒng)過程,、生物多樣性和生態(tài)系統(tǒng)服務(wù)的,。管理和恢復(fù)戰(zhàn)略: 鑒于氣候變化對生態(tài)系統(tǒng)的影響，有必要制定管理和恢復(fù)戰(zhàn)略,，以維持生態(tài)系統(tǒng)的功能和服務(wù),。生態(tài)系統(tǒng)生態(tài)學(xué)家正在研究基于生態(tài)系統(tǒng)的適應(yīng)等不同策略在減輕氣候變化對生態(tài)系統(tǒng)影響方面的有效性。生態(tài)系統(tǒng)生態(tài)學(xué)的研究可以在幾個(gè)方面與全球氣候變化,、碳氮循環(huán)和生物多樣性喪失聯(lián)系起來,。這里有一些例子: 氣候變化和生態(tài)系統(tǒng)過程: 氣候變化通過改變溫度和降水模式影響生態(tài)系統(tǒng)過程，如碳(C)和氮(N)循環(huán),。生態(tài)系統(tǒng)生態(tài)學(xué)家研究氣候變化對這些過程的影響,，以及它們?nèi)绾畏答伒綒夂蛳到y(tǒng)中。碳氮循環(huán)與全球氣候變化: 碳氮循環(huán)是全球碳氮循環(huán)的重要組成部分,，對全球氣候變化有重要影響,。生態(tài)系統(tǒng)生態(tài)學(xué)家研究生態(tài)系統(tǒng)中碳和氮循環(huán)的速率和機(jī)制，以及它們?nèi)绾问艿綒夂蜃兓挠绊?。生物多樣性喪失和生態(tài)系統(tǒng)過程: 生物多樣性喪失可以對生態(tài)系統(tǒng)過程產(chǎn)生重大影響,，如養(yǎng)分循環(huán)、初級(jí)生產(chǎn)力和分解,。生態(tài)系統(tǒng)生態(tài)學(xué)家研究生物多樣性喪失對這些過程的影響,，以及它們可能如何影響生態(tài)系統(tǒng)的功能和服務(wù)?；谏鷳B(tài)系統(tǒng)的減緩氣候變化方法: 基于生態(tài)系統(tǒng)的方法,，如造林、再造林和生態(tài)系統(tǒng)恢復(fù),，可以通過固碳,、加強(qiáng)生物多樣性和改善生態(tài)系統(tǒng)功能，幫助減輕氣候變化的影響,。生態(tài)系統(tǒng)生態(tài)學(xué)家研究這些方法的有效性以及如何利用它們來應(yīng)對氣候變化,?？偟膩碚f，生態(tài)系統(tǒng)生態(tài)學(xué)為理解生態(tài)系統(tǒng),、全球氣候變化,、碳氮循環(huán)以及生物多樣性喪失之間復(fù)雜的相互作用提供了一個(gè)框架。通過研究這些相互作用,，我們可以制定減輕氣候變化影響和保護(hù)生態(tài)系統(tǒng)功能和服務(wù)的戰(zhàn)略,。

Ecosystem ecology is a sub-discipline of ecology that focuses on studying the interactions between living organisms and their physical environment in a particular ecosystem. Ecosystem ecology examines the flow of energy and nutrients through ecosystems, the relationships between different species within ecosystems, and how ecosystems respond to environmental changes over time. Ecosystem ecology aims to understand the complex relationships and feedback loops that exist within ecosystems and how they contribute to the functioning and stability of ecosystems. By studying the structure and function of ecosystems, ecosystem ecologists can gain insights into how ecosystems are affected by natural and human-induced disturbances, such as climate change, pollution, and habitat destruction. Ecosystem ecology is a highly interdisciplinary field that draws on concepts and techniques from biology, geology, chemistry, physics, and mathematics. The ultimate goal of ecosystem ecology is to provide a comprehensive understanding of how ecosystems work and to inform management and conservation efforts aimed at preserving these important natural systems.

There are several hot topics in ecosystem ecology related to global climate change, as it is one of the most pressing environmental issues of our time. Some of these topics include: Impacts of warming temperatures on ecosystem processes: As temperatures continue to rise, ecosystem processes such as photosynthesis, respiration, and nutrient cycling are being affected. Researchers are studying how these changes in ecosystem processes will affect ecosystem functioning and services. Shifts in species ranges and community dynamics: As temperatures warm, many species are shifting their ranges in response to changing climatic conditions. Ecosystem ecologists are studying how these shifts are affecting species interactions and community dynamics. Carbon cycle feedbacks: Ecosystems play a crucial role in the global carbon cycle, and changes in ecosystem processes due to climate change are affecting the amount of carbon that ecosystems can store. Researchers are studying how these changes will feedback into the climate system, potentially exacerbating climate change. Impacts of extreme weather events: Climate change is leading to more frequent and intense extreme weather events such as droughts, floods, and wildfires. Ecosystem ecologists are studying how these events are affecting ecosystem processes, biodiversity, and ecosystem services. Management and restoration strategies: Given the impacts of climate change on ecosystems, there is a need to develop management and restoration strategies to maintain ecosystem functioning and services. Ecosystem ecologists are studying the effectiveness of different strategies, such as ecosystem-based adaptation, in mitigating the impacts of climate change on ecosystems.

The research of ecosystem ecology can be connected to global climate change, C and N cycling, and biodiversity loss in several ways. Here are a few examples: Climate change and ecosystem processes: Climate change is affecting ecosystem processes such as carbon (C) and nitrogen (N) cycling by altering temperature and precipitation patterns. Ecosystem ecologists study the impacts of climate change on these processes and how they might feedback into the climate system. Carbon and nitrogen cycling and global climate change: Carbon and nitrogen cycling are important components of the global carbon and nitrogen cycles, which have significant impacts on global climate change. Ecosystem ecologists study the rates and mechanisms of C and N cycling in ecosystems and how they are affected by climate change. Biodiversity loss and ecosystem processes: Biodiversity loss can have significant impacts on ecosystem processes such as nutrient cycling, primary productivity, and decomposition. Ecosystem ecologists study the impacts of biodiversity loss on these processes and how they might affect ecosystem functioning and services. Ecosystem-based approaches to climate change mitigation: Ecosystem-based approaches such as afforestation, reforestation, and ecosystem restoration can help mitigate the impacts of climate change by sequestering carbon, enhancing biodiversity, and improving ecosystem functioning. Ecosystem ecologists study the effectiveness of these approaches and how they can be used to address climate change. Overall, ecosystem ecology provides a framework for understanding the complex interactions between ecosystems, global climate change, C and N cycling, and biodiversity loss. By studying these interactions, we can develop strategies for mitigating the impacts of climate change and preserving ecosystem functioning and services.

是什么賦予生命力量？陽光和營養(yǎng)物質(zhì)是如何影響我們賴以生存的植物的,？溫室氣體和其他污染物如何降解構(gòu)成生態(tài)系統(tǒng)的植物,、動(dòng)物和微生物種群之間的相互作用？生態(tài)系統(tǒng)生態(tài)學(xué)是關(guān)于環(huán)境中有生命和無生命的組成部分的研究,，這些因素如何相互作用,，以及自然和人類引起的變化如何影響它們的功能。了解生態(tài)系統(tǒng)如何工作,，首先要了解陽光如何轉(zhuǎn)化為可用能源,，營養(yǎng)循環(huán)的重要性，以及人類對環(huán)境的影響,。植物將陽光轉(zhuǎn)化為可利用的碳基能源形式,。種群的初級(jí)生產(chǎn)力和次級(jí)生產(chǎn)力可以用來確定生態(tài)系統(tǒng)中的能量流動(dòng)。研究大氣的影響——二氧化碳將對未來的農(nóng)業(yè)生產(chǎn)和食品質(zhì)量產(chǎn)生影響,。生態(tài)系統(tǒng)生態(tài)學(xué)的一個(gè)新焦點(diǎn)是氣候變化,。世界正在以驚人的速度發(fā)生變化，從某些地區(qū)的降水量增加到減少,，從草原到沙漠(荒漠化)或從森林到草原(干旱增加)的生態(tài)系統(tǒng)正在發(fā)生變化,。生態(tài)系統(tǒng)生態(tài)學(xué)家目前正在研究氣候變化的原因和影響，希望有一天能盡量減少我們對地球的影響,，并保護(hù)我們今天所知道的自然生態(tài)系統(tǒng),。為了豐富對生態(tài)系統(tǒng)生態(tài)學(xué)的理解，從這個(gè)介紹性的概述開始,，然后探索你將在下面找到的其他概述,。

What powers life? How do sunlight and nutrients affect the plants we depend on? How do greenhouse gases and other contaminants degrade the interactions among the plant, animal, and microbial populations that comprise ecosystems? Ecosystem ecology is the study of these and other questions about the living and nonliving components within the environment, how these factors interact with each other, and how both natural and human-induced changes affect how they function. Understanding how ecosystems work begins with an understanding of how sunlight is converted into usable energy, the importance of nutrient cycling, and the impact mankind has on the environment. Plants convert sunlight into usable forms of energy that are carbon based. Primary and secondary production in populations can be used to determine energy flow in ecosystems. Studying the effects of atmospheric? CO2 will have future implications for agricultural production and food quality. A new focus in ecosystem ecology has been climate change. The world is being altered at an alarming pace from greater to lesser precipitation in some areas to change in ecosystems from grasslands to desert (desertification) or forests to grasslands (increased aridity). Ecosystem ecologists are now studying the causes and effects of climate change, hoping to one day minimize our impact on the planet and preserve natural ecosystems as we know them today. To develop a rich understanding of ecosystems ecology, begin with this introductory overview, and then explore the other summaries you’ll find below.

生物多樣性、穩(wěn)定性和生態(tài)系統(tǒng)功能 

氣候變化和其他人類驅(qū)動(dòng)的（人為的）環(huán)境變化將在未來幾十年繼續(xù)造成生物多樣性的喪失（Sala等人,，2000年）,，此外全球已經(jīng)發(fā)生的物種滅絕率很高（Stork，2010年）,。生物多樣性是一個(gè)可以用來描述各種不同尺度的生物多樣性的術(shù)語,，但在這種情況下，我們將重點(diǎn)描述物種多樣性,。物種在生態(tài)系統(tǒng)中發(fā)揮著重要作用,，因此當(dāng)?shù)睾腿蛭锓N的損失可能威脅到人類賴以生存的生態(tài)系統(tǒng)服務(wù)的穩(wěn)定性（McCann 2000）,。例如，植物物種利用太陽的能量通過光合作用固定碳,，而這一重要的生物過程為無數(shù)動(dòng)物消費(fèi)者提供了食物鏈的基礎(chǔ)。在生態(tài)系統(tǒng)層面,，所有植物物種的總生長都被稱為初級(jí)生產(chǎn),，正如我們將在本文中看到的那樣，由不同數(shù)量和組合的植物組成的群落可能具有非常不同的初級(jí)生產(chǎn)率,。生態(tài)系統(tǒng)功能的這一基本指標(biāo)與全球糧食供應(yīng)和氣候變化率有關(guān),，因?yàn)槌跫?jí)生產(chǎn)反映了二氧化碳（一種溫室氣體）從大氣中去除的速度。目前,，人們對自然和人類管理的生態(tài)系統(tǒng)的穩(wěn)定性非常擔(dān)憂,，特別是考慮到已經(jīng)發(fā)生的無數(shù)全球變化。穩(wěn)定性可以用幾種方式來定義,，但穩(wěn)定系統(tǒng)最直觀的定義是,，盡管環(huán)境條件不斷變化，但其可變性很低（即與平均狀態(tài)的偏差很?。?。這通常被稱為系統(tǒng)的阻力。彈性是穩(wěn)定性的一個(gè)不同方面,，表明生態(tài)系統(tǒng)在受到擾動(dòng)或其他擾動(dòng)后恢復(fù)原狀的能力,。 

Introduction: Biodiversity, Stability, and Ecosystem Functioning 

Climate change and other human-driven (anthropogenic) environmental changes will continue to cause biodiversity loss in the coming decades (Sala et al. 2000), in addition to the high rates of species extinctions already occurring worldwide (Stork 2010). Biodiversity is a term that can be used to describe biological diversity at a variety of different scales, but in this context we will focus on the description of species diversity. Species play essential roles in ecosystems, so local and global species losses could threaten the stability of the ecosystem services on which humans depend (McCann 2000). For example, plant species harness the energy of the sun to fix carbon through photosynthesis, and this essential biological process provides the base of the food chain for myriad animal consumers. At the ecosystem level, the total growth of all plant species is termed primary production, and — as we'll see in this article — communities composed of different numbers and combinations of plant species can have very different rates of primary production. This fundamental metric of ecosystem function has relevance for global food supply and for rates of climate change because primary production reflects the rate at which carbon dioxide (a greenhouse gas) is removed from the atmosphere. There is currently great concern about the stability of both natural and human-managed ecosystems, particularly given the myriad global changes already occurring. Stability can be defined in several ways, but the most intuitive definition of a stable system is one having low variability (i.e., little deviation from its average state) despite shifting environmental conditions. This is often termed the resistance of a system. Resilience is a somewhat different aspect of stability indicating the ability of an ecosystem to return to its original state following a disturbance or other perturbation. 

物種特性、功能性狀和資源利用 

物種多樣性有兩個(gè)主要組成部分：物種豐富度（當(dāng)?shù)厝郝渲械奈锓N數(shù)量）和物種組成（群落中物種的身份）,。雖然大多數(shù)關(guān)于生態(tài)系統(tǒng)多樣性和穩(wěn)定性之間關(guān)系的研究都集中在物種豐富度上，但正是物種組成的變化為解釋物種豐富度和生態(tài)系統(tǒng)功能之間的關(guān)系提供了機(jī)制基礎(chǔ)。物種在資源利用,、環(huán)境耐受性以及與其他物種的相互作用方面各不相同,，因此物種組成對生態(tài)系統(tǒng)的功能和穩(wěn)定性有重大影響。表征一個(gè)物種生態(tài)功能的特征被稱為功能特征,，具有相似特征的物種通常被歸類為功能組,。當(dāng)來自不同功能組的物種出現(xiàn)在一起時(shí)，它們可以表現(xiàn)出互補(bǔ)的資源利用,，這意味著它們在不同的時(shí)間使用不同的資源或使用相同的資源,。例如，兩種動(dòng)物捕食者可能會(huì)消耗不同的獵物,，因此它們不太可能相互競爭,，從而使系統(tǒng)中捕食者的總生物量更高。就植物而言,，所有物種都可能利用相同的資源（空間,、光照,、水、土壤養(yǎng)分等）,，但在生長季節(jié)的不同時(shí)間,，例如大草原的早季和晚季草。增加物種多樣性可以通過增加物種使用互補(bǔ)資源的可能性來影響生態(tài)系統(tǒng)功能,，如生產(chǎn)力,，也可以增加群落中存在特別多產(chǎn)或高效物種的可能性。例如,，高植物多樣性可以通過更全面和/或更有效地開發(fā)土壤資源（如養(yǎng)分,、水）來提高生態(tài)系統(tǒng)生產(chǎn)力。雖然初級(jí)生產(chǎn)是本文中提及最多的生態(tài)系統(tǒng)功能,，但分解和養(yǎng)分周轉(zhuǎn)等其他生態(tài)系統(tǒng)功能也受到物種多樣性和特定物種特征的影響,。 

Species Identity, Functional traits, and Resource-Use

Species diversity has two primary components: species richness (the number of species in a local community) and species composition (the identity of the species present in a community). While most research on the relationship between ecosystem diversity and stability has focused on species richness, it is variation in species composition that provides the mechanistic basis to explain the relationship between species richness and ecosystem functioning. Species differ from one another in their resource use, environmental tolerances, and interactions with other species, such that species composition has a major influence on ecosystem functioning and stability. The traits that characterize the ecological function of a species are termed functional traits, and species that share similar suites of traits are often categorized together into functional groups. When species from different functional groups occur together, they can exhibit complementary resource-use, meaning that they use different resources or use the same resources at different times. For example, two animal predators may consume different prey items, so they are less likely to compete with one another, allowing higher total biomass of predators in the system. In the case of plants, all species may utilize the same suite of resources (space, light, water, soil nutrients, etc.) but at different times during the growing season — for example, early- and late-season grasses in prairies. Increasing species diversity can influence ecosystem functions — such as productivity — by increasing the likelihood that species will use complementary resources and can also increase the likelihood that a particularly productive or efficient species is present in the community. For example, high plant diversity can lead to increased ecosystem productivity by more completely, and/or efficiently, exploiting soil resources (e.g., nutrients, water). While primary production is the ecosystem function most referred to in this article, other ecosystem functions, such as decomposition and nutrient turnover, are also influenced by species diversity and particular species traits. 

多樣性-穩(wěn)定性理論 

理論模型表明，多樣性和穩(wěn)定性之間可能存在多種關(guān)系,，這取決于我們?nèi)绾味x穩(wěn)定性（Ives&Carpenter評論,，2007年）。穩(wěn)定性可以在生態(tài)系統(tǒng)層面上定義——例如,，牧場主可能對草原生態(tài)系統(tǒng)在幾年內(nèi)維持牛飼料初級(jí)生產(chǎn)的能力感興趣,，這些年的平均溫度和降水量可能會(huì)有所不同。圖1顯示了如果物種對環(huán)境波動(dòng)的反應(yīng)各不相同,，一個(gè)植物群落中存在多個(gè)物種可以穩(wěn)定生態(tài)系統(tǒng)過程,，從而使一個(gè)物種的豐度增加可以補(bǔ)償另一個(gè)物種豐度減少。生物多樣性群落也更有可能包含賦予生態(tài)系統(tǒng)恢復(fù)力的物種,，因?yàn)殡S著群落積累物種,，其中任何一個(gè)物種都有更高的機(jī)會(huì)擁有能夠適應(yīng)不斷變化的環(huán)境的特征。這樣的物種可以緩沖系統(tǒng)免受其他物種的損失,?？茖W(xué)家們提出了保險(xiǎn)假說來解釋這一現(xiàn)象（Yachi&Loreau，1999年）,。在這種情況下,，物種身份和特定的物種特征是穩(wěn)定系統(tǒng)的驅(qū)動(dòng)力，而不是物種豐富度本身,。相反,，如果穩(wěn)定性是在物種水平上定義的，那么更多樣化的組合實(shí)際上可以具有更低的物種水平穩(wěn)定性,。這是因?yàn)榭梢跃奂谝粋€(gè)特定群落中的個(gè)體數(shù)量是有限的,，因此隨著群落中物種數(shù)量的增加，群落中物種的平均種群規(guī)模也會(huì)下降。例如,，在圖2中,，每個(gè)簡單的群落只能包含三個(gè)個(gè)體，因此隨著群落中物種數(shù)量的增加,，任何給定物種擁有大量個(gè)體的概率都會(huì)下降,。一個(gè)特定物種的種群規(guī)模越小，由于隨機(jī)波動(dòng),，它就越有可能在當(dāng)?shù)販缃^,，因此在物種豐富度較高的情況下，當(dāng)?shù)販缃^的風(fēng)險(xiǎn)應(yīng)該更大,。因此，如果穩(wěn)定性是從維持群落中特定種群或物種的角度來定義的,，那么在隨機(jī)聚集的群落中增加多樣性應(yīng)該會(huì)給系統(tǒng)帶來更大的破壞穩(wěn)定的機(jī)會(huì),。

Diversity-Stability Theory 

Theoretical models suggest that there could be multiple relationships between diversity and stability, depending on how we define stability (reviewed by Ives & Carpenter 2007). Stability can be defined at the ecosystem level — for example, a rancher might be interested in the ability of a grassland ecosystem to maintain primary production for cattle forage across several years that may vary in their average temperature and precipitation. Figure 1 shows how having multiple species present in a plant community can stabilize ecosystem processes if species vary in their responses to environmental fluctuations such that an increased abundance of one species can compensate for the decreased abundance of another. Biologically diverse communities are also more likely to contain species that confer resilience to that ecosystem because as a community accumulates species, there is a higher chance of any one of them having traits that enable them to adapt to a changing environment. Such species could buffer the system against the loss of other species. Scientists have proposed the insurance hypothesis to explain this phenomenon (Yachi & Loreau 1999). In this situation, species identity — and particular species traits — are the driving force stabilizing the system rather than species richness per se。In contrast, if stability is defined at the species level, then more diverse assemblages can actually have lower species-level stability. This is because there is a limit to the number of individuals that can be packed into a particular community, such that as the number of species in the community goes up, the average population sizes of the species in the community goes down. For example, in Figure 2, each of the simple communities can only contain three individuals, so as the number of species in the community goes up, the probability of having a large number of individuals of any given species goes down. The smaller the population size of a particular species, the more likely it is to go extinct locally, due to random — stochastic — fluctuations, so at higher species richness levels there should be a greater risk of local extinctions. Thus, if stability is defined in terms of maintaining specific populations or species in a community, then increasing diversity in randomly assembled communities should confer a greater chance of destabilizing the system. 多樣性-穩(wěn)定性關(guān)系的實(shí)驗(yàn)和觀測評估 

近年來,，人們對多樣性,、穩(wěn)定性和生態(tài)系統(tǒng)功能之間的關(guān)系進(jìn)行了大量研究（Balvanera等人，2006年,，Hooper等人,，2005年）。第一個(gè)測量多樣性和穩(wěn)定性之間關(guān)系的實(shí)驗(yàn)操縱了水生微宇宙中的多樣性,，即包含四個(gè)或更多營養(yǎng)級(jí)的微型實(shí)驗(yàn)生態(tài)系統(tǒng),，包括初級(jí)生產(chǎn)者、初級(jí)和次級(jí)消費(fèi)者以及分解者（McGrady-Steed等人,，1997,，Naeem和Li，1997）,。這些實(shí)驗(yàn)發(fā)現(xiàn),，物種多樣性賦予了幾種生態(tài)系統(tǒng)功能空間和時(shí)間穩(wěn)定性。功能群內(nèi)部和功能群之間的物種豐富度賦予了穩(wěn)定性（Wardle等人,，2000年）,。當(dāng)一個(gè)系統(tǒng)中有多個(gè)物種具有類似的生態(tài)作用時(shí)，它們有時(shí)被認(rèn)為是“功能冗余的”,。但這些實(shí)驗(yàn)表明,，當(dāng)單個(gè)物種因環(huán)境變化（如氣候變化）而喪失時(shí)，具有功能冗余的物種可能在確保生態(tài)系統(tǒng)穩(wěn)定方面發(fā)揮重要作用,。最近,，科學(xué)家們研究了植物多樣性對陸地生態(tài)系統(tǒng)生態(tài)系統(tǒng)穩(wěn)定性的重要性，尤其是草原，那里的主要植被離地面較低,，易于實(shí)驗(yàn)操作,。1995年，David Tilman及其同事在Cedar Creek生態(tài)系統(tǒng)科學(xué)保護(hù)區(qū)建立了168個(gè)實(shí)驗(yàn)地塊,，每個(gè)地塊的大小為9 x 9米（圖3A）,，并從18種可能的多年生植物中隨機(jī)抽取1、2,、4,、8或16種進(jìn)行播種（Tilman等人，2006）,。地塊被除草以防止新物種入侵,，生態(tài)系統(tǒng)的穩(wěn)定性被衡量為初級(jí)生產(chǎn)隨時(shí)間的穩(wěn)定性。在收集數(shù)據(jù)的十年里,，氣候存在顯著的年際變化,，研究人員發(fā)現(xiàn)，隨著時(shí)間的推移,，更多樣地的產(chǎn)量更穩(wěn)定（圖3B）,。相比之下，在更多樣地,，種群穩(wěn)定性下降（圖3C）,。這些實(shí)驗(yàn)結(jié)果與上一節(jié)中描述的理論一致，預(yù)測由于單個(gè)物種的種群規(guī)模下降,，物種多樣性的增加將與生態(tài)系統(tǒng)水平的穩(wěn)定性增加呈正相關(guān),，而與物種水平的穩(wěn)定性負(fù)相關(guān)。操縱多樣性的實(shí)驗(yàn)因其空間尺度小,、時(shí)間尺度短而受到批評,，那么在較大的空間尺度和較長的時(shí)間尺度上,，自然聚集的群落會(huì)發(fā)生什么呢,？在一項(xiàng)對內(nèi)蒙古自然聚集草原植被的24年研究中,，Bai等人（2004）觀察到物種,、功能群和整個(gè)群落的生物量隨著生長季節(jié)降水的強(qiáng)烈年際變化而變化。他們發(fā)現(xiàn),，雖然單個(gè)物種的豐度波動(dòng),，但特定功能組內(nèi)的物種往往會(huì)有不同的反應(yīng),，因此一個(gè)物種豐度的下降會(huì)被另一個(gè)物種的豐度的增加所補(bǔ)償,。這種補(bǔ)償在波動(dòng)的環(huán)境中穩(wěn)定了整個(gè)社區(qū)的生物量生產(chǎn)力（見圖1）,。這些發(fā)現(xiàn)表明，當(dāng)?shù)匚锓N的豐富性——無論是在功能群內(nèi)部還是在功能群之間——都賦予了自然聚集群落生態(tài)系統(tǒng)過程的穩(wěn)定性。水生生態(tài)系統(tǒng)的實(shí)驗(yàn)也表明,，大規(guī)模過程在穩(wěn)定生態(tài)系統(tǒng)方面發(fā)揮著重要作用。加拿大的一項(xiàng)全湖酸化實(shí)驗(yàn)發(fā)現(xiàn),，盡管物種多樣性因酸化而下降,，但物種組成發(fā)生了顯著變化,，生態(tài)系統(tǒng)功能得以維持（Schindler 1990）,。這表明，如果有足夠的時(shí)間和適當(dāng)?shù)臄U(kuò)散機(jī)制,，新物種可以在區(qū)域物種庫中定居,，并補(bǔ)償那些在當(dāng)?shù)厥サ奈锓N（Fischer等人，2001）,。這一觀察結(jié)果強(qiáng)調(diào)了在自然棲息地經(jīng)歷環(huán)境變化時(shí)保持連通性的重要性。Experiments and Observations

Can Evaluate the Diversity-Stability Relationship A wealth of research into the relationships among diversity, stability, and ecosystem functioning has been conducted in recent years (reviewed by Balvanera et al. 2006, Hooper et al. 2005). The first experiments to measure the relationship between diversity and stability manipulated diversity in aquatic microcosms — miniature experimental ecosystems — containing four or more trophic levels, including primary producers, primary and secondary consumers, and decomposers (McGrady-Steed et al. 1997, Naeem & Li 1997). These experiments found that species diversity conferred spatial and temporal stability on several ecosystem functions. Stability was conferred by species richness, both within and among functional groups (Wardle et al. 2000). When there is more than one species with a similar ecological role in a system, they are sometimes considered 'functionally redundant.' But these experiments show that having functionally redundant species may play an important role in ensuring ecosystem stability when individual species are lost due to environmental changes, such as climate change. More recently, scientists have examined the importance of plant diversity for ecosystem stability in terrestrial ecosystems, especially grasslands where the dominant vegetation lies low to the ground and is easy to manipulate experimentally. In 1995, David Tilman and colleagues established 168 experimental plots in the Cedar Creek Ecosystem Science Reserve, each 9 x 9 m in size (Figure 3A), and seeded them with 1, 2, 4, 8 or 16 species drawn randomly from a pool of 18 possible perennial plant species (Tilman et al. 2006). Plots were weeded to prevent new species invasion and ecosystem stability was measured as the stability of primary production over time. Over the ten years that data were collected, there was significant interannual variation in climate, and the researchers found that more diverse plots had more stable production over time (Figure 3B). In contrast, population stability declined in more diverse plots (Figure 3C). These experimental findings are consistent with the theory described in the prior section, predicting that increasing species diversity would be positively correlated with increasing stability at the ecosystem-level and negatively correlated with species-level stability due to declining population sizes of individual species. Experiments manipulating diversity have been criticized because of their small spatial and short time scales, so what happens in naturally assembled communities at larger spatial scales over longer time scales? In a 24-year study of naturally assembled Inner Mongolia grassland vegetation, Bai et al. (2004) observed variation in the biomass of species, functional groups, and the whole community in response to strong interannual variation in growing-season precipitation. They found that while the abundance of individual species fluctuated, species within particular functional groups tended to respond differently such that a decrease in the abundance of one species was compensated for by an increase in the abundance of another. This compensation stabilized the biomass productivity of the whole community in a fluctuating environment (see Figure 1). These findings demonstrate that local species richness — both within and among functional groups — confers stability on ecosystem processes in naturally assembled communities. Experiments in aquatic ecosystems have also shown that large-scale processes play a significant role in stabilizing ecosystems. A whole-lake acidification experiment in Canada found that although species diversity declined as a result of acidification, species composition changed significantly and ecosystem function was maintained (Schindler 1990). This suggests that given sufficient time and appropriate dispersal mechanisms, new species can colonize communities from the regional species pool and compensate for those species that are locally lost (Fischer et al. 2001). This observation emphasizes the importance of maintaining connectivity among natural habitats as they experience environmental changes.