NATURAL ECOSYSTEM

Natural Ecosystem

Natural Ecosystem

Introduction

The term ecosystem is defined by the Convention on Biological Diversity as a dynamic complex of plant, animal, and microorganism communities and their nonliving environment interacting as a functional unit. As further detailed by the convention, this definition does not specify any particular spatial unit or scale. Thus, the term ecosystem does not, necessarily, correspond to the terms biome or ecological zone but can refer to any functioning unit at any scale. The scale of analysis and action should be determined by the different functions, properties, spatial levels involved and by the issues highlighted in this entry.

Discussion

Ecosystem of Prince William Park

Ecosystem services of Prince William Forest Ecosystem services include all benefits humans derive from ecosystem functions, which in turn includes the habitat, biological, and system properties of an ecosystem. These services include (but are not limited to) nutrient cycling, gas regulation, climate regulation, waste treatment, and provision of raw materials. Forests provide all of these services and are receiving increasing scrutiny with an eye toward the quantities of these services. Two services that have garnered attention in the literature are carbon storage and carbon sequestration. These two services are of importance due to their links to global climate change and are primary outputs of multiple models such as the UFORE model. Several dozen cities have assessed the ecosystem services of the urban forests with the UFORE model, such as Tampa San Francisco, Minneapolis, and the borough Brooklyn in New York. Locally the ecosystem services provided by the urban forests of both Baltimore and Washington DC have been assessed with the UFORE model Prince William Forest Park is the first natural forest that has been surveyed with the UFORE model (Costanza et al, 2000).

Carbon storage and sequestration

Carbon storage is measured as aboveground biomass by the UFORE model. White oak accounted for the most carbon stored within the park, representing approximately 19% of park's carbon as aboveground biomass. The white oak population consisted of larger (and ostensibly older) trees which were probably not growing as quickly as other species and therefore were not estimated to be sequestering carbon at the rate of other species. Oak also stored the most carbon in Washington DC, though the contribution to the total carbon storage of the DC urban forest was smaller (13.6%).

Air pollution removal

Air pollution removal is another key ecological service provided by forests. Pollution removal by a given forest is determined by the amount of pollution in the region, assessed using information gathered from air-pollution monitoring stations scattered across the United States. The Washington DC UFORE project used data from sources located within the city itself, the 60 ideal sources of air pollution data. Prince William Forest Park used data from the city of Manassas, located northwest of the park in central Prince William County. Accordingly, the actual quantity of air pollution abated by the park may be greater or less than that reported, as the exact amount of each pollutant within the park is not precisely ...