Late Pleistocene megafauna extinction leads to missing pieces of ecological space in a North American mammal community.
Late Pleistocene megafauna extinction leads to missing pieces of ecological space in a North American mammal community.
复制标题
DOI：
10.1073/pnas.2115015119
复制
发表时间：
2022-09-27
影响因子：
11.1
通讯作者：
Newsome, Seth D.
中科院分区：
文献类型：
--
作者：
Smith, Felisa A.;Smith, Emma A. Elliott;Villasenor, Amelia;Tome, Catalina P.;Lyons, S. Kathleen;Newsome, Seth D.
大型哺乳动物的数量正在以惊人的速度下降。它们的减少对生态系统造成了严重的后果，因为它们具有体型较小的动物无法复制的重要功能作用。了解它们的衰退或潜在灭绝将如何影响生态系统过程至关重要且具有时间敏感性。在这里，我们用古记录来类比现代生物多样性的丧失。我们通过表征事件前后动物体型和饮食同位素生态位的变化，研究了更新世晚期巨型动物灭绝对德克萨斯州爱德华兹高原哺乳动物群落的影响。我们发现群落发生了重大重组，特别是在食肉动物中，生态复杂性丧失，以及许多空置的生态位。复杂性的丧失可能意味着生态系统弹性的降低。大型哺乳动物的保护状况十分严峻。它们的减少会产生严重后果，因为它们具有体型较小的动物无法复制的独特生态作用。在这里，我们利用更新世末期巨型动物灭绝的化石记录来探索过去生物多样性丧失的后果。我们描述了事件前后德克萨斯州哺乳动物群落的同位素和体型生态位，以评估对幸存物种（> 1 kg）的生态和生态相互作用的影响。灭绝前，存在多种 C4 食草动物、C3 食草动物和混合饲养动物，类似于现代非洲稀树草原，可能专门针对幼年食草动物的两种剑齿虎物种。灭绝后，身体尺寸和同位素生态位空间丧失，一些幸存者的 δ13C 和 δ15N 值发生变化。我们看到猫科动物中中型食肉动物的释放：美洲虎，现在是顶级食肉动物，进入了以前由灭绝的猫科动物占据的特殊同位素生态位。以前缺席的 Puma 变得常见，而 lynx 则转向消耗更多基于 C4 的资源。兔形目动物是唯一转向 C4 资源的食草动物。从更新世到全新世的体型变化是特定于物种的，一些动物（鹿、野兔）明显变大，而另一些动物（野牛、兔子）则变小，或者没有表现出气候变化或生物多样性丧失的变化。总体而言，全新世的身体尺寸同位素生态位急剧减少，并且生态复杂性丧失了相当多。我们的结论是，生物多样性的丧失导致了幸存者的重组以及我们社区内许多“缺失的部分”；如果不进行干预，地球上支撑巨型动物的剩余生态系统的丧失可能会遭受同样的命运。
Populations of large-bodied mammals are declining at an alarming rate. Their decline has serious ecosystem consequences because they have important functional roles that are not replicated by smaller-bodied animals. Understanding how their decline or potential extinction will influence ecosystem processes is critically important and time-sensitive. Here, we use the paleorecord as an analogy for modern biodiversity loss. We examine consequences of the terminal-Pleistocene megafauna extinction on a mammal community from the Edwards Plateau, Texas by characterizing changes in animal body size and dietary isotopic niche before and after the event. We find significant reorganization of the community, particularly among carnivores, a loss of ecological complexity, and many vacant niches. The loss of complexity likely meant a reduction in ecosystem resilience. The conservation status of large-bodied mammals is dire. Their decline has serious consequences because they have unique ecological roles not replicated by smaller-bodied animals. Here, we use the fossil record of the megafauna extinction at the terminal Pleistocene to explore the consequences of past biodiversity loss. We characterize the isotopic and body-size niche of a mammal community in Texas before and after the event to assess the influence on the ecology and ecological interactions of surviving species (>1 kg). Preextinction, a variety of C4 grazers, C3 browsers, and mixed feeders existed, similar to modern African savannas, with likely specialization among the two sabertooth species for juvenile grazers. Postextinction, body size and isotopic niche space were lost, and the δ13C and δ15N values of some survivors shifted. We see mesocarnivore release within the Felidae: the jaguar, now an apex carnivore, moved into the specialized isotopic niche previously occupied by extinct cats. Puma, previously absent, became common and lynx shifted toward consuming more C4-based resources. Lagomorphs were the only herbivores to shift toward C4 resources. Body size changes from the Pleistocene to Holocene were species-specific, with some animals (deer, hare) becoming significantly larger and others smaller (bison, rabbits) or exhibiting no change to climate shifts or biodiversity loss. Overall, the Holocene body-size-isotopic niche was drastically reduced and considerable ecological complexity lost. We conclude biodiversity loss led to reorganization of survivors and many “missing pieces” within our community; without intervention, the loss of Earth’s remaining ecosystems that support megafauna will likely suffer the same fate.
登录
查看更多内容
影响因子：
5.9
作者：
Asner, Gregory P.;Vaughn, Nicholas;Levick, Shaun
通讯作者：
Levick, Shaun
影响因子：
1.4
作者：
Binder, Wendy J.;Van Valkenburgh, Blaire
通讯作者：
Van Valkenburgh, Blaire
DOI：
10.1016/j.palaeo.2003.12.008
发表时间：
2004-03-30
影响因子：
3
作者：
Coltrain, JB;Harris, JM;Allen, J
通讯作者：
Allen, J
DOI：
10.1073/pnas.1704949114
发表时间：
2017-07-25
影响因子：
11.1
作者：
Ceballos, Gerardo;Ehrlich, Paul R.;Dirzo, Rodolfo
通讯作者：
Dirzo, Rodolfo
DOI：
10.1073/pnas.1502549112
发表时间：
2016-01-26
影响因子：
11.1
作者：
Doughty, Christopher E.;Roman, Joe;Svenning, Jens-Christian
通讯作者：
Svenning, Jens-Christian