An ecosystem is a community of living life forms in conjunction with the nonliving parts of their environment things like air, water and mineral soil, interacting as a system. These biotic and abiotic parts are regarded as linked together through nutrient cycles and energy goes. As ecosystems are defined by the network of interactions among life forms, and between life forms and their environment, they may be of any size but typically encompass particular, restricted spaces though some scientists say that the complete planet is an ecosystem. Energy, water, nitrogen and soil minerals are other essential abiotic parts of an ecosystem. The energy that goes through ecosystems is acquired mainly from the sun. It usually enters the system through photosynthesis, a procedure that also captures carbon from the atmosphere. By feeding on plants and on one another, animals play an important role in the motion of matter and energy through the system. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter, decomposers release carbon back to the atmosphere and help nutrient cycling by converting nutrients stored in dead biomass back to a form that may be readily used by plants and other microbes. Ecosystems are controlled both by external and interior factors. External factors like weather, the parent material that forms the soil, and topography control the in general structure of an ecosystem and the way things work inside it, but aren't themselves influenced by the ecosystem. Other external factors include time and possible biota. Ecosystems are dynamic entitiesinvariably, they're subject to regular commotions and are in the procedure of recovering from some past disturbance. Ecosystems in alike environments that are located in different parts of the world can have different characteristics simply because they contain different species. The introduction of non native species can because considerable shifts in ecosystem function. interior factors not only control ecosystem processes but are controlled by them and are frequently subject to feedback loops. While the resource inputs are usually controlled by external processes like weather and parent material, the availability of these resources inside the ecosystem is controlled by interior factors like decomposition, root competition or shading. Other interior factors include disturbance, succession and the types of species present. though humans exist and operate inside ecosystems, their accumulative effects are big enough to influence external factors like weather. Biodiversity affects ecosystem function, as do the processes of disturbance and succession. Ecosystems supply a range of products and services upon which people rely, the rules of ecosystem management propose that rather than managing individual species, natural resources should be managed at the level of the ecosystem itself. Classifying ecosystems into ecologically homogeneous units is an important step towards efficient ecosystem management, but there's no single, agreed upon way to do this.