题目：Defence against vertebrate herbivores trades off into architectural and low nutrient strategies amongst savanna Fabaceae species 生活在稀树草原的一些豆科植物为了抵御植食动物（不含昆虫）的啃食，进化出了物理防御或者低营养的策略
摘要
Herbivory contributes substantially to plant functional diversity and 植食作用对植物功能多样性有着明显的贡献， in ways that move far beyond direct defence trait patterns, 这种贡献不仅体现在直接跟防御有关的形状的规律上， as effective growth strategies under herbivory require modification of multiple functional traits that are indirectly related to defence. 在植食压力下植物如何有效成长，还需要间接跟防御相关的多种功能特征在此压力下的修正。 In order to understand how herbivory has shaped plant functional diversity, 要理解植食作用是如何塑造了植物的功能多样性， we need to consider the physiology and architecture of the herbivores and how this constrains effective defence strategies. 我们需要从植食动物的生理和构造上来理解它们如何限制植物的有效防御策略（反正就是互相对抗吧）。 Here we consider herbivory by mammals in savanna communities that range from semi-arid to humid conditions. 本文研究不同水分条件下（半干旱到湿润）哺乳动物对萨王纳植物群落的影响。
We posited that the saplings of savanna trees can be grouped into two contrasting defence strategies against mammals, namely architectural defence versus low nutrient defence. 我们提出，萨王纳树种的幼树依据他们对植食动物的防御策略聚为两类，结构型和低能型（手动狗头）。
We provide a mechanistic explanation for these different strategies based on the fact that plants are under competing selection pressures to limit herbivore damage and outcompete neighbouring plants. 对于这些植物在来自植食者和周围植物的竞争选择压力下采取的不同策略，我们提出一个机制性的解释：
Plant competitiveness depends on growth rate, itself a function of leaf mass fraction (LMF) and leaf nitrogen per unit mass (Nm). 植物的竞争力与其生长速率有关，而生长速率跟叶重比例（LMF）和单位质量叶片氮（Nm）都是成正比的（公式1）。
Architectural defence against vertebrates (which includes spinescence) limits herbivore access to plant leaf materials,
结构型防御（包括刺）妨碍了植食动物对植物叶片的取食，
and partly depends on leaf-size reduction,
且通常伴随有叶片面积的减小，
thereby compromising LMF.
所以LMF较小。
Low nutrient defence requires that leaf material is of insufficient nutrient value to support vertebrate metabolic requirements,
低营养型防御植物的叶子营养满足不了脊椎动物的代谢需求，
which depends on low Nm.
因为他们的Nm低。
Thus there is an enforced tradeoff between LMF and Nm, leading to distinct trait suites for each defence strategy.
所以如果要生长速率高，就不可能LMF和Nm都低，只能选一样。（不能都选吗？能，但是一旦资源放在两边，就不可能竞争的过资源放一边的，选择比努力重要啊朋友）
We demonstrate this tradeoff by showing that numerous traits can be distinguished between 28 spinescent (architectural defenders) and non-spinescent (low nutrient defenders) Fabaceae tree species from savannas, where mammalian herbivory is an important constraint on plant growth.
我们比较了生活在植食压力很大的萨王纳里分属这两类防御策略的28个豆科树种的许多特征，展示了LMF-Nm之间的权衡。（到这里都没提水的事…)
Distributions of the strategies along an LMF-Nm tradeoff further provides a predictive and parsimonious explanation for the uneven distribution of spinescent and non-spinescent species across water and nutrient gradients.
因为不同的物种在这个LMF-Nm权衡光谱上，可以想见带刺的植物算是选择了低LMF，即高Nm, 那可能需要生活在营养条件比较好的地方，（跟水什么关系?光和作用吗?)，于是造成了有刺植物跟没刺植物在水分和营养梯度上的不均匀分布。
最后一句真的很突然，因为说实验设计那里没有提到有水分或者养分的处理啊。当然摘要里面不说不代表没有。只能说老板真的不是很在意摘要。