Environmental Engineering Reference
In-Depth Information
Implications for Biodiversity, Conservation Planning,
and Sustainability
Whereas better understanding of the effects of ecotones on biodiversity is impor-
tant for evolutionary and ecological pure science purposes, it also has many
implications for conservation of biodiversity, sustainability, and practical deci-
sion-making. Some scientists have argued that because ecotones hold marginal
populations at the edge of the range of many species, where abundances may be
lower and populations more prone to local extinctions than other parts of the range,
these ecotonal areas have low value for conservation as they will not persist over
time, for example, if the surrounding environments become fragmented (e.g., [
9
]).
There has been an interesting discussion in the literature in recent years regarding
whether transitional areas are valuable for conservation (e.g., see Smith et al. [
36
]
versus Brooks [
4
]). Substantial conservation attention has been given in recent
years to the understanding and mapping of biodiversity patterns and the underlying
processes, and toward predicting the effects of global change. Ecotone and bound-
ary regions, where change, shifts, and variability occur naturally in both space and
time, could serve as useful models for understanding, monitoring, and predicting
the response of individuals, populations, and communities to changing environments
[
2
,
6
,
29
]. In addition, while some scientists suggest that ecotone populations are more
likely to be negatively affected by climate change [
9
], other researchers have argued
that ecotonal areas sustain populations that are adapted to changing, fluctuating, and
unstable environments and, as such, these populations may better be able to persist in
the face of predicted change (see further discussion in [
17
]). This is especially relevant
since climate shifts are expected, according to some studies, to be rapid and extreme in
boundary regions between ecosystems [
2
]. By examining changes in ecotone locations
over time, these areas may potentially serve as “early warning” indicators of global
changes [
6
,
29
]. However, the response depends on the spatial and temporal scales
examined andmay be a useful indicator mainly at global spatial scales and rather coarse
timescales. Therefore, this area deserves further attention owing to the complexity of
the factors shaping the location of ecotones in space and time.
Much research in the past decade has focused on prioritizing conservation efforts
and determining what areas are most important and valuable for conservation. Two
main approaches have been suggested: The first approach includes a search for
biodiversity hotspots, or areas with especially high species richness, endemism, and
rarity. A second approach has been to select areas that are complementary, and hold
biodiversity not present in other areas. Ecotones may provide a unique opportunity
to conserve both high species richness and high complementarity. Due to their
relatively small size, it may prove a cost-effective strategy to further conserve
ecotone regions and to explicitly include them in future systematic conservation
planning, given they potentially provide a high return on investment having small
area and high biodiversity. Undoubtedly, if these areas have the potential to maintain
and to generate species richness as well as unique and novel species and forms, they
deserve far greater research attention than they are currently receiving [
36
]. Never-
theless, conservation plans for ecotones should not be considered independent of
