DISSERTATION RESEARCH: Herbivore Pressure, Inga Chemistry, Toxicity and Defensive Ants: Comparison of two Tropical Communities

植物和以它们为食的动物占地球上生物的50%，它们之间的相互作用对天然森林的多样性和动态有着深远的影响。植物已经进化出一系列惊人的化学防御来阻止食草动物，而食草动物则用解毒机制来反击。这种相互选择被认为是热带森林物种多样性的原因。然而，我们对植物有效防御的选择强度的形成机制知之甚少。本研究将探讨防御化学的一个广泛的新热带属，印加，通过比较在巴拿马和厄瓜多尔的网站的差异。我们预测，草食动物的丰度，因此选择植物来保护自己将更大的在厄瓜多尔的更多样化和非季节性的森林。在每个地点，我们将量化食草动物的压力，Inga的多样性和丰富性，对非蛋白质氨基酸和类黄酮（Inga的主要化学防御类别）的投资，实验室试验中防御对食草动物的毒性，以及自然界中对叶子的损害率。尽管草食动物和植物在化学防御进化中的相互选择被认为是重要的，但很少有研究在复杂的自然群落中解决这个问题。

Plants and the animals that eat them make up 50% of the organisms on earth and the interactions among them have profound implications for the diversity and dynamics of natural forests. Plants have evolved an astounding array of chemical defenses to deter herbivores, and herbivores have countered with detoxification mechanisms. This reciprocal selection is believed to be responsible for the great species diversity of tropical forests. However, we know little of the mechanisms shaping the strength of selection for effective plant defenses. This study will examine differences in the defensive chemistry of a widespread Neotropical genus, Inga, by comparing sites in Panama and Ecuador. We predict that herbivore abundance, and hence the selection for plants to defend themselves will be greater in the more diverse and non-seasonal forest in Ecuador. At each site we will quantify herbivore pressure, diversity and abundance of Inga, investments in non-protein amino acids and flavonoids (the main classes of chemical defenses in Inga), toxicity of defenses to herbivores in laboratory trials, and rates of damage to leaves in nature. Despite the presumed importance of reciprocal selection by herbivores and plants on the evolution of chemical defenses, very few studies have addressed this in complex natural communities.