Extent of Alabama's Terrestrial Nature Reserve System in Representing Ecosystem Diversity: A Coarse-Filter Gap Analysis

Exponential human population growth has resulted in overexploitation of resources, the introduction of alien invasive species, habitat destruction and fragmentation, and the subsequent global endangerment and extinction of many species. Globally, governmental, and nongovernmental programs, use nature reserves (NRs) to mitigate against the decline of biological diversity by protecting habitats and their inhabitants from fragmentation and other negative anthropogenic impacts. However, numerous studies conducted at multiple spatial and temporal scales have revealed that existing NRs do not effectively represent biodiversity, or are experiencing declines in biodiversity because of anthropogenic encroachment around NRs. Our study examined the spatial distribution and characteristics of the NR system in Alabama using coarse-filter gap analysis. We compiled a dataset of private and public NRs in Alabama, and analyzed the extent and effectiveness of Alabama's NR system in representing ecosystem diversity. We found that NRs occupied approximately 840,000 ha (6.2%) of land area in Alabama. Public NRs covered 6.0% of Alabama land area, and private NRs covered 0.2% of the land area. We found a latitudinal shift in NR parcels from majority private NR parcel presence in northeast Alabama to majority public parcel ownership in southwest Alabama. The statewide mean NR parcel area was 2149.47 ha; the mean public NR area was 4789 ha; the mean private NR area was 151 ha; and the mean distance (isolation) between NRs was 4.5 km. We hypothesize the distribution of parcel property types throughout Alabama was related to socioeconomic status, race, and metropolitan areas throughout the state. Our results may be used to improve conservation planning in Alabama, and our approach used as a model to assess NR systems in other states or regions.