Towards an integrated understanding of terrestrial ecosystem feedbacks to climate change.
Towards an integrated understanding of terrestrial ecosystem feedbacks to climate change.
复制标题
全面了解陆地生态系统对气候变化的反馈。
作者：
Rebecca Sanders‐DeMott;N. Smith;P. Templer;J. Dukes
自1870年以来，陆地生物圈储存的碳量相当稳定地增长，抵消了相当于2000年的二氧化碳。29%的人为温室气体排放（Le Qu er e等人，2015年）的报告。然而，碳-气候耦合模型并不同意这种汇将如何受到下一个世纪预计气候变化的影响（Friedlingstein等人，2014年）。为了帮助限制这种不确定性，生态学家使用越来越多的创造性和创新性的方法，以更好地了解陆地碳汇在多个尺度和组织层次。例如，研究人员目前正在考虑利用一系列研究方法和框架，协调应对多种生态系统进程。这些综合方法在最近举行的美国生态学会100年年会上的两次口头会议上得到了展示：一次题为"气候变暖对陆地生态系统地上-地下反馈的影响"，另一次题为"解决地球系统模型中生态不确定性的创造性方法"。在这两次有组织的会议上，发言者展示了如何使用综合办法来回答生态问题，以提高我们对陆地生态系统如何应对和反馈未来气候变化的理解。虽然不可能对生态系统内部和之间的每一个过程和反馈都有一个机械的、可量化的了解，但将系统作为一个整体来考虑，包括尚未完全了解的过程，是至关重要的。Quinn托马斯（弗吉尼亚理工大学，布莱克斯堡，弗吉尼亚州，美国）结束了他关于氮限制如何在地球系统模型（ESM）中表示的演讲（托马斯等人，2015年），展示了一张威斯敏斯特宫的一座塔楼的照片，覆盖在莫奈的经典印象派画作《伦敦雾》之上。托马斯将小塔楼的清晰照片与整个宫殿的模糊背景并列，以提醒科学界不要过于狭隘地关注特定的生态系统对气候变化的反应，因为我们只了解生态系统的一个子集。这一发言说明，在试图了解生态系统对全球变化的复杂反应时，即使整体情况并不十分清楚，也必须采取更加综合的办法。本报告提供了三种综合方法的实例，以了解会上展示的陆地生态系统对气候变化的反应和反馈。其中包括：（1）关注地上和地下过程之间的联系;（2）使用模型来生成可检验的假设;（3）在一系列空间和时间尺度上整合观察、实验和建模。
Since 1870, fairly consistent growth in the amount of carbon stored by the terrestrial biosphere has offset the equivalent of c. 29% of anthropogenic greenhouse gas emissions (Le Qu er e et al., 2015). However, coupled carbon–climate models do not agree as to how this sink will be affected by projected changes in climate over the next century (Friedlingstein et al., 2014). To help constrain this uncertainty, ecologists have used increasingly creative and innovative approaches to better understand the terrestrial carbon sink across multiple scales and levels of organization. For example, researchers are now considering coordinated responses of multiple ecosystem processes, utilizing an array of research methodologies and frameworks. These integrated approaches were on display during two organized oral sessions at the recent 100 Annual Meeting of the Ecological Society of America: one titled ‘Effects of climate warming on aboveground–belowground feedbacks in terrestrial ecosystems’ and another titled ‘Creative approaches for addressing ecological uncertainty in Earth System Models’. The speakers in these two organized sessions demonstrated the use of integrated approaches to answering ecological questions to improve our understanding of how terrestrial ecosystems will respond and feed back to future climate change. Although achieving a mechanistic, quantifiable understanding of every process and feedback within and among ecosystems is not possible, considering the system as a whole, including processes not yet fully understood, is critical. QuinnThomas (Virginia Tech, Blacksburg, VA, USA) concluded his talk on how nitrogen limitation is represented in Earth SystemModels (ESMs) (Thomas et al., 2015) by showing a photograph of a single tower of the Palace of Westminster overlaid on top of Monet’s classic impressionist painting of the entire Palace, titled ‘London Fog.’ Thomas juxtaposed the clarity of the smaller tower photograph against the blurred background of the Palace in its entirety to caution the scientific community against focusing too narrowly on a particular ecosystem response to climate change simply because we understand only a subset of the ecosystem. This presentation illustrated the importance of taking a more integrated approach when trying to understand the complexities of ecosystem responses to global change, even if the entirety of the picture is not perfectly clear. This report provides examples of three integrative approaches to understanding terrestrial ecosystem responses and feedbacks to climate change on display at the meeting. These include: (1) focusing on the connection between aboveground and belowground processes; (2) usingmodels to generate testable hypotheses; and (3) integrating observations, experiments, andmodeling across a range of spatial and temporal scales.