The main conservation agencies of the United States utilize
a course-filter conservation approach, which is about “protecting
representative portions of each ecological community across a landscape.” This
approach is recognized as the most effective approach for protecting the most
biodiversity, or number of species, in a particular community. In order to
determine the best sites for course-filter conservation, adequate data to
analyze ecosystems is needed. This data is collected and analyzed through the
Gap Analysis Program to determine the adequacy of existing conservation efforts
and to prioritize the best sites for course-filter conservation. Lots of data
exist for gap analysis but none of these data sets are complete. In this paper,
the authors conduct a gap-analysis on ecosystem types with the best available data.
This represents the first continental-scale gap analysis conducted in the
United States.
Geospatial data is aggregated for each state and used to
determine the stewardship status for parcels of land. This status ranges in degrees
of conservation. Conserved lands are rated status 1 to 3, and land that is not
conserved at all is status 4. This data represents the most complete source of
data available. Gap analyses use National Land Cover Data Set geospatial data
on vegetation cover to make inferences on the biological health of a region,
but this data is often low quality due to the lack of high resolution satellite
imagery. To develop a quality national map on vegetation cover, this data was
combined with data on ecosystem regions from the Nature Conservancy. A specific
combination of ecosystem region type and land cove type is called an ecosystem
analysis unit, each a unique type of ecosystem.
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| Figure 1. Conservation status (Table 1) of lands in the Protected Areas Database for the continental United States. |
Using GIS, the area with stewardship statuses 1, 2, and 3
was analyzed to determine the effectiveness of existing conservation. There are
three problems with attempting this sort of analysis:
1.
“Deciding what level of protection for a
particular ecosystem type is sufficient.”
2.
“Defining a baseline amount of area for each
ecosystem analysis unit.”
3.
“Deciding which GAP status lands constitute the
conservation estate.”
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| Figure 2. Conservation of ecosystem analysis units: (a) current conservation, (b) hypothetical 10% conservation of all natural lands. |
Of the 554 ecosystem analysis units, an average of 4% of the
area was within areas of active conservation. The results of this study
illustrate that “the majority of ecosystem analysis units have a small
percentage of their total area residing in lands that are managed to support
biodiversity.” This finding shows the urgent need for more complete data to be
able to design more effective conservation that encompasses high priority
areas. The continuous improvement of GIS technologies is important for the
development of better and more complete data.
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Dietz, Robert W.; Czech, Brian. (2005). Conservatoin Deficits for the Continental United States: an Ecosystem Gap Analysis. Conservation Biology, 19(5), 1478-87.
This is really cool information. The second figure you used in the post is really helpful in visualizing how little is being conserved now and what a big difference it could make if just 10% of those lands were conserved. I'm curious if the article provided any information on how significant 10% conservation/recovery is to an ecosystem. Also, what exactly is the Gap Analysis...thing? Does it analyze gaps between land fragments? Thanks.
ReplyDeleteThanks Elise! 10% is an arbitrary figure because 1. The necessities for each species and type of habitat varies and 2. the paper states that "30 to 50% of a given community or ecosystem type needs to be conserved to maintain 80 to 90% of the species (Soul´e & Sanjayan 1998; Groves 2003).
ReplyDeleteGap Analysis refers to the collection and analysis of data on species and habitat within the network of conservation land in the United States. The purpose for these analyses is basically to determine whether wildlife and their habitats are adequately protected. Using this information conservation agencies are able to assess the effectiveness of their programs and to design better ones. So, no, it doesn't directly deal with land fragmentation, although this is probably a consideration when gathering the data.
Great article, I think it highlights how current conservation policy is not being practiced on a purely biology bases but politics plays a big role. I like how the Gap analysis is applied, which basically measures a questions, what is the gap between the way things are, and the ideal way we want them. Figure A shows you current state, Figure B is the ideal. The Gap is the difference between the two. As you can see in the figure there is a major difference. Great application of GIS!
ReplyDeleteThe second map really does make a statement about the amount of conservation that is being done. When you look at the white areas (water or non natural lands) this is what we would consider to be the bread basket which supply's most of the united states with food. When professor Anwar refers to politics being the reason this area is not conserved is it because of the amount of food supplied and the government trying to keep costs low?
ReplyDelete