小柯机器人

气候变暖能够削弱营养传递效率
2021-03-04 14:45

英国埃克塞特大学Gabriel Yvon-Durocher、伦敦大学玛丽女王学院Mark Trimmer等研究人员合作发现,气候变暖能够削弱营养传递效率 。这一研究成果于2021年3月1日在线发表在国际学术期刊《自然》上。

据研究人员介绍,在自然生态系统中,能量从资源到获取者的转移效率决定着食物网的生物量结构。通常,一个营养级产生的能量大约有10%能够被累积到下一个营养级。最近的理论表明,如果温度升高会增加代谢增长的成本,这种能量转移可能会受到进一步的限制,但缺乏在整个生态系统中的实验证实。

研究人员对经历7年实验变暖的人工池塘中淡水浮游生物的氮转移效率(代表整体能量转移)进行了量化。研究人员提供了第一个直接的实验证据,相对于环境条件,4°C的升温会降低最多56%的营养传递效率。此外,在温水池塘中,浮游植物和浮游动物的生物量均较低,这表明了能量吸收、转化和转移的主要变化。这些新发现使观察到的变暖导致个体分类增长成本和碳分类效率在不同分类单元中的变化,以及生态系统一级总呼吸量与初级总产值之比的增加。

这些结果表明,随着地球变暖,通过光合作用固定的碳比例将越来越多地流失到大气中,从而削弱了通过食物链的能量流,这对更大的获取者和整个生态系统的功能产生了负面影响。 

附:英文原文

Title: Warming impairs trophic transfer efficiency in a long-term field experiment

Author: Diego R. Barneche, Chris J. Hulatt, Matteo Dossena, Daniel Padfield, Guy Woodward, Mark Trimmer, Gabriel Yvon-Durocher

Issue&Volume: 2021-03-01

Abstract: In natural ecosystems, the efficiency of energy transfer from resources to consumers determines the biomass structure of food webs. As a general rule, about 10% of the energy produced in one trophic level makes it up to the next1–3. Recent theory suggests this energy transfer could be further constrained if rising temperatures increase metabolic growth costs4, although experimental confirmation in whole ecosystems is lacking. We quantified nitrogen transfer efficiency (a proxy for overall energy transfer) in freshwater plankton in artificial ponds exposed to 7 years of experimental warming. We provide the first direct experimental evidence that, relative to ambient conditions, 4°C of warming can decrease trophic transfer efficiency by up to 56%. In addition, both phytoplankton and zooplankton biomass were lower in the warmed ponds, indicating major shifts in energy uptake, transformation and transfer5,6. These new findings reconcile observed warming-driven changes in individual-level growth costs and carbon-use efficiency across diverse taxa4,7–10 with increases in the ratio of total respiration to gross primary production at the ecosystem level11–13. Our results imply that an increasing proportion of the carbon fixed by photosynthesis will be lost to the atmosphere as the planet warms, impairing energy flux through food chains, with negative implications for larger consumers and the functioning of entire ecosystems.

DOI: 10.1038/s41586-021-03352-2

Source: https://www.nature.com/articles/s41586-021-03352-2

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

分享到:

0