Porter, W.* P.; Budaraju, S.; Stewart, W.E.; Ramankutty, N.: Physiology on a landscape scale: applications in ecological theory and conservation practice

Plant properties play a crucial role in a novel and unsuspected way that involves the physiology of animals as does effects of climate variation in time and space in how many species can coexist in the community. This paper describes how climate variation in time and space can constrain community structure on a global scale. We explore body size scaling and the energetic consequences in terms of absorbed mass and energy and expended mass and energy. We explain how morphology, specific physiological properties, and temperature dependent behaviors are key variables that link individual energetics to population dynamics and community structure. For mammals ranging in size from mice to elephants we show that calculated metabolic costs are in agreement with experimental data. We also demonstrate how we can do the same for birds ranging in size from hummingbirds to ostriches. We show the impact of changing posture and changing air temperatures on energetic costs for birds and mammals. We demonstrate how optimalbody size that maximizes the potential for growth and reproduction changes with changing climatic conditions and with diet quality. Climate and diet may play important roles in constraining community structure (collection of functional types of different body sizes) at local and global scales. Thus, multiple functional types may coexist in a locality in part because of the temporal and spatial variation in climate and seasonal food variation. We illustrate how the models can be applied in a conservation and biodiversity context to a rare and endangered species of parrot, the Orange-bellied Parrot of Australia and Tasmania.