Habitat loss Human Health Risk Ecological Risk H Socioeconomic Risk Habitat loss is the conversion of land from one use to another, specifically the development of wild or agricultural lands to urban and suburban land uses. Habitat loss also includes the conversion of natural habitat to agriculture, the conversion of dunes to seawalls, and the modification of wetlands by dams and channelization. Habitat degradation is the leading cause of endangerment for all groups of organisms in the mainland Unites States, ranking ahead of exotic species, pollution, over-exploitation, and disease. In New Jersey, these changes affect thousands of acres per year, resulting in the reduction of available habitat for native plant and animal species and decreasing the resilience of ecosystems to accommodate other natural and human caused stressors. What’s at risk? What are the ecological impacts in New Jersey? Most of the plants and animals listed as endangered or threatened in New Jersey are imperiled due to habitat loss. Endangered tree frogs native to the Pinelands are being displaced by more disturbance-tolerant bullfrogs. Pinelands plant communities have also been altered as native species are replaced by invasive exotics in more developed areas. Bird species diversity is also known to decrease as the proportion of urban land increases. New Jersey has lost 40% of its wetlands and 35% of the Pine Barrens since presettlement times, and has 50% less farmland than in 1950. Naturally vegetated shoreline areas provide habitat and perform critical ecosystem services. Only 29% of Barnegat Bay’s shoreline, for example, remains undeveloped. Rates of development continue to increase. During 1984- What’s being done? Due to human population pressures, returning currently developed land to its former state is not practical on a large scale. Consequently, the primary management focus should be on preventing further impacts. As of 1998, New Jersey had 920,000 acres of permanently protected open space (29% of New Jersey’s total 3.2 million acres). Development is regulated in the 1.1 million acre Pinelands National Reserve, and most of Barnegat Bay’s remaining salt marshes and undeveloped shoreline are under some form of protection. 133 Final Report of the New Jersey State Comparative Risk Project STRESSOR SUMMARIES Habitat loss affects all terrestrial and aquatic plant and animal populations and ecosystems statewide, especially those found on undeveloped, unprotected land. Unprotected forests and wetlands are particularly at risk. Regions that still contain large tracts of critical wildlife habitat are especially vulnerable to the effects of habitat loss. These include the Pinelands region (1.1 million acres) and the New Jersey Highlands (640,000 acres). Socioeconomic impacts of habitat loss are included among the impacts discussed under Land Use Change. 1995, 11 of New Jersey’s 21 counties experienced rates of development greater than 20%, and several grew by more than 30%. Developed acreage in Salem and Cumberland counties increased by 50% and 42%, respectively, during this time. In addition to the direct effects on species composition, land use change also compromises ecosystem functions such as nutrient cycling and water purification and storage.