Mediterranean Ecosystems Worldwide: Climate Adaptation - Recent Advances and Issues in Environmental Science - page 33

and the average and 5, 10, 25, 50, 75, 90, and 95 percentiles of the projected percent
change for all simulations in a given emissions scenario were calculated. This provides
both a measure of the range and the central tendency of the ensemble of projected
changes [20]. We considered using a weighted-average, but since we do not have a
testing dataset for the future locations of the MCE, and other studies have found little
increases in predictive power with a weighted average compared to a non-weighted
average [21], we used only the average.
We spatially combined the current MCE and all of the future MCE projections to
calculate the percent of AOGCM simulations predicting an expansion or contraction
of the MCE for each grid cell on the globe. We defi ned seven categories based on
whether areas were in the current MCE or not, and the number of AOGCM simula-
tions that project the area will be in the future MCE (Table 1). These categories were
mapped using the suite of AOGCM simulations for each emissions scenario.

Table 1. Mapped categories for the MCE future projections.

Percent of AOGCM simulations projecting
area will be in future MCE

Category Area incurrent MCE?

Confi dent Stable Yes 90-100%

Likely Stable Yes 66-90%

Uncertain Yes 33-66%

Likely Contraction Yes 10-33%

Confi dent Contraction Yes 0-10%

Confi dent Expansion No 90-100%

Likely Expansion No 66-90%

doi: 1 0.1371 / journal.pone.0006392.t001

We determined the amount of land protected and modifi ed through development
and land conversion within the current and projected future MCE [5]. We used all
World Conservation Union categories (I-VI) in the 2006 World Database on Pro-
tected Areas to map areas that are protected in the current MCE and in the areas
where the MCE is projected to expand (www.unep-wcmc.org/wdpa) [22]. Marine
protected areas were not included, and protected areas with only point location were
mapped as circles with the correct area. We converted the polygon data to a binary
2.5 min resolution grid by assigning a grid cell a value of 1 if the center of the cell
falls within a protected area polygon, and 0 if not. For spatial data on modifi ed or
converted areas, we used the areas classifi ed as “cultivated and managed areas” and
“artifi cial surfaces” in the Global Land Cover 2000 (www-gvm.jrc.it/glc2000) [23].
We converted these data to a binary 2.5 min resolution grid where 1 indicated a grid
cell is converted and 0 indicated it is not. We performed a spatial combination of
these two binary grids with the current and projected future MCE grids. Areas that