PNAS：非洲植食动物食量惊人

长江

作者：Tyler R. Kartzinel

来源：PNAS

发布时间：2015/7/6 13:15:42

非洲植食动物食量惊人



美国史密森尼杂志报道称，一项新的研究发现，非洲大型食草动物有着独特的植物偏好，这或许可以解释在萨瓦纳热带草原上植食动物物种繁多的原因。

这项发表于美国《国家科学院院刊》的研究描述了研究人员如何收集大象、平原斑马、黑斑羚的粪便样本，并利用一种相对较新的基因研究方法把在粪便样本中发现的基因序列和植物DNA相匹配的过程。研究人员表示，这项发现有助于该地区的物种保护行动。（红枫）

http://www.pnas.org/content/112/26/8019.abstract

长江

DNA metabarcoding illuminates dietary niche partitioning by African large herbivores

Abstract

Niche partitioning facilitates species coexistence in a world of limited resources, thereby enriching biodiversity. For decades, biologists have sought to understand how diverse assemblages of large mammalian herbivores (LMH) partition food resources. Several complementary mechanisms have been identified, including differential consumption of grasses versus nongrasses and spatiotemporal stratification in use of different parts of the same plant. However, the extent to which LMH partition food-plant species is largely unknown because comprehensive species-level identification is prohibitively difficult with traditional methods. We used DNA metabarcoding to quantify diet breadth, composition, and overlap for seven abundant LMH species (six wild, one domestic) in semiarid African savanna. These species ranged from almost-exclusive grazers to almost-exclusive browsers: Grass consumption inferred from mean sequence relative read abundance (RRA) ranged from >99% (plains zebra) to <1% (dik-dik). Grass RRA was highly correlated with isotopic estimates of % grass consumption, indicating that RRA conveys reliable quantitative information about consumption. Dietary overlap was greatest between species that were similar in body size and proportional grass consumption. Nonetheless, diet composition differed between all species—even pairs of grazers matched in size, digestive physiology, and location—and dietary similarity was sometimes greater across grazing and browsing guilds than within them. Such taxonomically fine-grained diet partitioning suggests that coarse trophic categorizations may generate misleading conclusions about competition and coexistence in LMH assemblages, and that LMH diversity may be more tightly linked to plant diversity than is currently recognized.

African savannas body size competition coexistence ungulates

goole译：

抽象

利基分区有利于物种共存在一个资源有限的世界，从而丰富的生物多样性。几十年来，生物学家们试图了解大型哺乳动物食草动物（LMH）分区食物资源如何多样化组合。几个补充机制已经确定，其中包括草与nongrasses并且在使用同一植物的不同部位的时​​空分层的差分消耗。然而，在何种程度上LMH分区食品植物物种在很大程度上是未知的，因为全面的物种一级鉴定与传统方法比登天还难。我们用DNA metabarcoding量化饮食广度，组合，重叠和七丰富的LMH种（SIX野，一是国内）在半干旱非洲大草原。这些物种范围几乎独占食草动物几乎独占浏览器：草消费量从平均序列相对丰度读（RRA）的推断> 99％不等（平原斑马）<1％（犬羚属）。草RRA是高度相关的青草％的消费量估计同位素，表明RRA传达关于消耗可靠的定量信息。膳食重叠是最大的那名在车身尺寸和比例草消费的同类品种之间。尽管如此，饮食成分的所有物种，甚至对相匹配的大小，消化生理食草动物之间的差异，以及定位和饮食相似，有时更大跨越放牧和浏览比公会在其中。这样的分类学细粒度的饮食分区表明，粗营养分类已可以产生大约在LMH组合竞争和共存误导性的结论，那LMH多样性可能更紧密地联系在一起比目前公认的植物多样性。

非洲稀树草原 机身尺寸 竞争 共存 有蹄类动物