Download New Jersey`s Landscape Project

The Importance of Scale for
Endangered Species
New Jersey’s Landscape Project
Christina Leung
As the human population is
increasing, plant and animal habitats are
being exploited for human benefit. This
results in increased habitat loss and degradation, which threatens the survival of several
species. More people are becoming concerned about endangered species that are greatly
effected by human actions. Endangered species are those whose survival are in
immediate danger because of a loss or change in habitat, over-exploitation, predation,
competition, disease, disturbance, or contamination. Threatened species are those that
may become endangered if conditions surrounding them begin to or continue to
deteriorate (Conserve Wildlife, 2001). Therefore, it is important to understand the
complex interactions that comprise an organism’s habitat and the effects caused by
changes in those interactions.
The surrounding conditions should be based on the scale that the particular species
perceives its environment. Ecologists deal with familiar phenomena and usually study
them at anthropocentric scales rather than at the scale of the species. If a system is
studied at an inappropriate scale, its actual patterns may not be detected (Weins, 1989),
which is why the extent and grain is essential to choosing the correct scale to conduct a
study. Grain is defined by the size of the cells, which is usually of a scale relevant to the
organism being modeled, such as the species’ home range or territory size; extent is the
scope or domain of data with respect to size and duration of time considered (Dunning et
al., 1995). The correct scale would be the one that includes and characterizes the
landscape and focuses on a particular phenomena (Turner et al, 2001). What may seem
to be a small disturbance to a human being may not be for an ant. Each case is different
and depends solely on the species, making scale so vital to the planning process for
conserving endangered species.
Conservation efforts have traditionally been focused on individual species rather
than entire populations. The Endangered Species Act, which was passed in 1973,
focused on the protection of individual species. This was a starting point, but did not
meet efficiency standards, clearly seen from the long average time period between listing
and recovery-plan approval, far fewer recovery plans than listed species, and the lack of
biological data for species (Tear et al., 1995). The government used a reactive method
instead of a proactive approach for protection; attempts were made to protect a species
only after it was in danger. Not much thought was put into the planning process or how
to go about preserving species. Effort was lacking for conservation of entire ecosystems,
which is extremely important for conservation of species diversity (Tear et al., 1995).
The whole idea of scale was not fully incorporated into the planning process;
instead habitats were protected only if an endangered species was located there. The
surrounding area in which the particular species was found would be conserved, without
incorporating the spatial scale, size of the species, population density, habitat area, and
foraging. A great deal of money, time, effort, and species have been lost because of the
use of the individual approach (Tear et al., 1995). If recovery efforts focus solely on the
species level rather than the broader scope of recovery, substantial intra-specific variation
and genetic diversity will be lost (Tear et al., 1995).
An alternative to this management strategy is to focus conservation on a landscape
scale in addition to individual species. Both approaches need to be incorporated into
management to conserve species populations and their habitats. For the individuals of a
community to thrive and reproduce, entire areas where the populations are found need to
be conserved so that biodiversity and gene flow is maintained (Mladenoff et al., 1995). A
species may increase their risk of extinction when genetic material is not shared because
the species is not at the optimal fitness level. Tear et al. (1995) noted that probability of
extinction is inversely related to the extent of a population’s geographic distribution;
therefore, in order for the preservation of endangered and threatened species, the most
important factor would be to conserve the natural habitat on the scale at which the species
exists. This method concentrates on the bigger picture of ecosystem preservation while
maintaining local populations. This approach relates back to a fundamental concept of
landscape ecology, which emphasizes broad spatial scales and the ecological effects of
the spatial patterning on ecosystems (Turner et al., 1989). Turner also points out that
broad spatial scales are important for interactions and exchanges, which develop
heterogeneous landscapes.
Mladenoff et al. (1995) notes that many species require a large home range or
continuous foraging habitats, or they may consist of metapopulations on a smaller scale.
Take for example, the gray wolf in Minnesota compared to a salamander in New Jersey.
The salamander may require only one particular habitat within New Jersey while, the
wolf may utilize different habitats across many states due to its large-scale territorial
behavior. Wolf populations are not habitat specific and impose a spatial arrangement at
very large regional scales, making their behavior amenable to spatial analysis and
modeling (Mladenoff et al.).
Tools such as remote sensing (Ken’s Link?) and geographic information systems
(GIS) (John Luk’s Link?) allow for the manipulation and demonstration of spatial data to
represent the landscape at various scales. The data can then be utilized for spatial
models, which are important tools for investigating scale-related questions in population
ecology, especially in response to habitat change and fragmentation (Dunning et al.,
1995). Models are effective for developing sound management strategies in response to
regional land-use because they incorporate scales at the landscape level (Dunning et al.,
1995). Ecological processes can be studied from local to global spatial scales. Habitat
fragmentation, species location, and particular boundaries can all be incorporated into the
model to predict spatial and temporal changes within the system (Dunning et al., 1995).
Large-scale spatial analysis and modeling using GIS has been applied in studies of a
number of species, including the Gray Wolf, California Condor, and Mt. Graham red
squirrel (Mladenoff et al., 1995).
The New Jersey Division of Fish and Wildlife’s Endangered and Non-Game
Species Program (ENSP) has formulated the Landscape Project, for the preservation of
wildlife habitat in the state of New Jersey. The project incorporates the use of spatially
explicit models through GIS maps. The maps include all land-use and land-cover types
at the state and local level. There are three separate maps for land cover types: forests,
wetlands, and grasslands. Ranking for critical habitat is given priority based on the
number of threatened/endangered species within the area and the distance to already
conserved areas (Niles, 1999). After identifying the location of an endangered species,
the proximity from an already conserved area is calculated. The closer the distance is to
protected lands, the higher the priority because of its possible connectivity. Five
categories within each land type area are created based first on the number of priority
species found on the parcel, and then the closeness to conserved area.
Raster maps are then overlain with data from the location of priority species to
determine their “critical habitat areas”. A critical habitat area is the location of a state
and federally listed endangered species (Niles, 1999). Each habitat area differs in size
requirements depending on the spatial scale that is perceived by the species. The
information on critical habitat areas is important for reviewing proposed changes to
planning area boundaries proposed by the counties (Conserve Wildlife 1999). Adding
land parcels to the critical habitat areas increases the connectivity between habitat
patches, and preserves endangered species on a broader scale. Isolated patches of land
are important as well but may receive lower priority because of increased edge effects
(Niles, 1999). Habitat patches become increasingly isolated as fragmentation increases,
making it more difficult for wildlife to travel between patches. Larger plots of land have
a greater interior area and a smaller edge effect, making them more suitable for edgesensitive species (Niles, 1999).
The Landscape Project has designated critical area habitat for selected species.
Depending on the size of the organism or the different life histories, each habitat will be
of different size because each responds to the same landscape in different ways (Dunning
et al., 1995). For example, Bald eagle nests that are active for at least five years have a
one km radius as their critical habitat area (Niles, 1999). Foraging area increases the
radius size by a minimum of three square km. This is basically the same for Peregrine
Falcons, Northern Harriers, and Ospreys. Colonial water birds and wading birds on the
other hand, have a 150 m area around the nesting area in the Atlantic Coastal landscape
in New Jersey (Niles, 1999). That is why the correct scale needs to be identified so that
the most realistic population dynamics are attained (Dunning et al., 1995).
The Landscape Project maps categorize areas not specifically considered for
conservation that may provide benefits to the species of interest. For example, lands
supporting lower intensity land uses can provide potential habitat linkages, and buffers
for wide-ranging species and other species of conservation interests (Hoctor et al., 2000).
The maps can also serve as a possible land-use indicator to help determine which areas
should be protected while other areas could be used for human activities. They can be
used to prioritize public and private land parcels for purchase through land acquisition
programs. Another benefit of the maps for any geographic scale is that they are available
through Internet (www.state.nj.us/dep/fgw) to all potential users, from government
agencies to the general public.
The Landscape Project is currently being uses in many states across the country.
Another example of the regional landscape scale approach is seen in Florida, where land
acquisition is aimed at lands that possess potential for connectivity along with
conservation significance priority (Hoctor et al., 2000). Land-use data and information
on ecological areas was used to locate larger areas of ecological priority. Hoctor’s study
was also designed with a more integrated approach to biodiversity conservation. One of
Hoctor’s many goals through this study is to facilitate the ability of ecosystems and
landscapes to function as dynamic systems and maintain biota, especially habitat
sensitive, endangered, and target species.
Conservation does not only entail biological aspects, but also include economic,
social, political, and scientific elements. The Landscape Project involves participation
from all groups, from the government down to landowners, land managers, and the
general public. Various scales are incorporated within the levels of government to
maintain the appropriate scales to which species can thrive in. These include federal,
state, county, municipal governmental agencies. Each level of government coordinates
with all other branches to maximize collaboration efforts.
Along with government interactions, public participation is also important for
maintaining local abundances of individual species (Tear et al.). Most of these
conservation efforts are currently under-funded or not funded at all by any general fund
tax revenues. Most of the revenues for the ENSP come from state income tax from
citizens who donate. The general public can actively participate by supporting wildlife
on their income tax forms. Property owners, whose lands or waters harbor endangered
species, can make use of habitat conservation plans. Within their community, people can
plant native plant species that will attract wildlife in their backyard. ENSP is constantly
seeking volunteers from local neighborhoods to assist with surveys and monitoring
programs. Education is also a critical element in citizen involvement, and ENSP
increases awareness by offering available speakers to speak to groups and organizations.
People may also search the Internet to learn more about the Landscape Project and take
scenic trips throughout the state parks to experience the abundance of rare resources this
state has to offer. Companies are also taking part by funding outreach programs,
education, and general operating costs that will directly influence the endangered
wildlife.
Implementing the Landscape Project to protect endangered species is not the only
means to prevent declines in population. Mitigating anthropogenic activities in critical
areas and restoring habitats should also be incorporated into the planning process so that
populations can regenerate. The concept of scale has to be considered when protecting
endangered species. The appropriate scale for conservation depends on species
requirements and interactions, and life history characteristics. Rare species need to be
monitored closely in order to determine the right scale to which their patterns can be
seen.
Landscape scale is proving to be the most appropriate scale for ecosystem
management, with particular emphasis on core areas, buffers, and corridors (Hoctor et al.,
2000). Broad scale analyses of connectedness need to be species-specific, especially
when dealing with associations of particular communities and metapopulations (Hoctor et
al., 2000). However, there is no longer a single optimal management strategy to recover
threatened species (Dunning et al., 1995). Optimal strategies will change through time as
the quality of data, amount and shape of natural areas change, emphasizing the necessity
of management in an adaptive context. That is why proper planning is essential before
any actions occur, so wise management choices based on scientific data and models can
be made (Tear et al., 1995). This is a very important concept and should be adapted by
any conservative program because the purpose of the Endangered Species Act is to
prevent the numbers of species from decreasing. If a reactive approach is taken, it might
be a lost effort of “too little, too late”.
Work Cited
Dunning, J.B., Stewart, D.J., Danielson, B.J., Noon, B.R., Root, T.L., Lamberson, R.H.,
Stevens, E.E. 1995. Spatial Explicit Population Models: Current Forms and Future
Uses. Ecological Applications, 5:3-11.
Hoctor, T.S. et al. 2000. Identifying a linked reserve system using a regional landscape
approach: The Florida ecological network. Conservation Biology, 14:984-1000.
Mladenoff, D.J., Sickley, T.A., Haight, R.G., Wydeven, A.P. 1995. A Regional
Landscape Analysis and Prediction of Favorable Gray Wolf Habitat in the Northern
Great Lakes Region. Conservation Biology, 9:279-294.
Niles, L.J. 1999. The Landscape Project.
Species Program.
New Jersey Endangered and Nongame
Tear, T.H., Scott, M.S., Hayward, P.H., Griffith, B. 1995. Recovery Plans and the
Endangered Species Act: Are Critisms Supported by Data? Conservation Biology,
9:182-195.
Turner, M.G., et al. Landscape Ecology in Theory and Practice: Pattern and Process.
Springer, 2001.
Weins, J.A. 1989. Spatial Scaling in Ecology. Ecology. 3:385-397.
1999. Conserve Wildlife Newsletter. Endangered and Nongame Species Program within
the Dept. of Environmental Protection’s Division of Fish, Game and Wildlife.
2000. Conserve Wildlife Newsletter. Endangered and Nongame Species Program within
the Dept. of Environmental Protection’s Division of Fish, Game and Wildlife.