Allochthonous inputs: integrating population changes and food-web dynamics

Most ecosystems are recipients of allochthonous materials that enhance in s itu productivity. Recent theoretical and empirical studies suggest that low to moderate inputs can stabilize food webs. However, depending on the trop hic levels that use the resource, food webs can become unstable as inputs i ncrease. Where large amounts of agricultural resources are transferred to n atural habitats, trophic dynamics change: trophic cascades can occur and ra re or uncommon species can become invasive. Rates of change in species abun dances can also be amplified by the effects of changes in legislation and m anagement practices on subsidized consumers.