Cross-Site Comparisons of Ecological Responses to Climate and Climate-Related Drivers

Climate (the average and variability of weather conditions over a period of time) is a primary driver of ecological systems. Important climate and climaterelated factors for ecosystems include precipitation, air and water temperature, ice cover duration, sea level, stream flow, solar radiation, and water clarity. These factors affect resources available to plants, animals, and microbes and act as environmental constraints on the suitable habitat for reproduction, growth, and survival of organisms. Changes in seasonal and annual climatic patterns can have important consequences for key ecosystem properties, such as species composition and diversity, phenology, migrations, trophic interactions, rates of nutrient cycling, and net primary production.