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- Permanent Link:
- http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI15061015/00001
Notes
- Abstract:
- 6 Protected areas are a crucial component of strategies for conserving biodiversity;
however, their selection and design are usually not informed about the impacts of
climate change. To inform future management of protected areas in Australia under
climate change scenarios, this project produced the first Australia-wide, assessment
of the magnitude of ecological impact that climate change could have on biodiversity,
using three state-of-the-art quantitative techniques. These analyses were then used
in detailed ecological assessments of climate impacts and adaptation options in four
major biomes—Hummock grasslands; Tropical savanna woodlands and grasslands;
Temperate grasslands and grassy woodlands; and Sclerophyll forests of south-eastern
Australia—using existing literature and technical information, as well as workshops
that elicited local knowledge and concerns.
Spatial modelling approaches
The project assessed the significance of future climatic change for biodiversity in two
scenarios (medium impact and high impact) and in two time frames (2030 and 2070)
by running three different spatial analyses across multiple environmental layers and
various types of biological information. Artificial Neural Networks (ANN) were used to
classify current environments by vegetation classes (largely structural), and then this
classification was applied to future environments. Generalised Dissimilarity Modelling
(GDM) was used to estimate the sensitivity of species composition of communities
to environmental variation. A Bayesian Belief Network (BBN) was used to incorporate
observed and expert information to assess changes in suitability of environmental
conditions for the alien invasive species buffel grass.
These analyses provide an index of “biotically scaled environmental stress”. By
stress we mean a force likely to lead to aggregate change from the current state of
biodiversity. By biotically scaled we mean that environmental variables have been
weighted according to their relative importance for Australian biodiversity. The most
important feature of this interpretation is that it describes change in the environment
(the external drivers of ecological change), not the amount or type of change in
biodiversity in response. Thus, these measures are free of many of the ecological
assumptions—often implicit—that apply to most predictions of biodiversity impacts.
Environmental and ecological change
The project predicts dramatic environmental change due to climate change:
these changes will be ecologically very significant, and will result in many novel
environments quite unlike those currently occurring anywhere on the continent,
and the disappearance of many environments currently occupied by Australian
biodiversity. While biodiversity impacts from these changed environments may
be buffered when species exploit natural variation in the environment, our results
suggest that the magnitude of change will overcome these buffering effects by
2070. Changing temperature, moisture availability and fire regimes are likely to
lead to changes in vegetation structure, and it is likely there will be a gradual
turnover of species along vegetation-structure gradients. Historical habitat loss and
fragmentation due to land clearing will exacerbate the impacts of climate change;
land-use intensification, as a response to climate change in agricultural and forestry
sectors, remains a major threat to biodiversity. Increases in fire weather across much
of Australia are very likely, which could have significant impacts on composition,
structure, habitat heterogeneity and ecosystem processes. Expansion of alien
species capable of altering fire regimes (e.g. buffel grass) is likely, and changes in
the interactions between species could be as important to ecological outcomes as
geographic shifts in suitable environment. Changes in climate variability, as well as
averages, could be important drivers of altered species interactions.
Adapting to climate change
Climate change is a fundamentally different biodiversity threat in its geographic
extent, magnitude and speed of potential changes. It poses a significant challenge for conservation scientists and practitioners at a time when the science of climate
change impacts is still developing and there is little certainty of the details of change.
Our results suggest that we will need to examine the threat to a range of biodiversity
values, then derive conservation objectives and programs that preserve ecological
processes while allowing or even facilitating changes in biodiversity states. We need
to increase the efficiency of limited conservation resources by focusing investment on
those places or species that achieve the “greatest marginal loss avoided”, but do this
using robust strategy that are effective under a wide range of future magnitudes and
types of change, and for a wide range of species.
The most appropriate local scale management response to the predicted high level
of biotically scaled environmental stress will vary between regions. However, the
project showed that the strategy underpinning the NRS is likely to be highly robust
in the face of significant environmental change. Some expansion of the NRS may be
needed to help biodiversity respond to the changing distributions of biotically scaled
environments across the continent.
Iterative changes to management will allow a staged approach to adapting to high
levels of future environmental change. A first step could be to focus on understanding
the implications of different changes that might occur for different areas of
conservation planning, and mainstreaming climate change into planning, rather
than treating it as a separate threat to manage. The second phase would focus on
conservation objectives, understanding that the choice between encouraging change,
managing change, passively allowing change, or actively minimising change will affect
management of protected areas. The third stage is to use information from the first
two stages to revise management strategies and adaption pathways across a series of
plans of management.
Key knowledge gaps
The science of biodiversity impacts is developing rapidly in Australia and
internationally but biodiversity managers are now working with high levels
of uncertainty. This project identified that a new discipline of climate change
biogeography, which attempts to integrate the disparate approaches and information
about climate change impacts, is needed. We will also need to have informed
debate in science, policy and public domains about the social values associated
with biodiversity, to develop suitable conservation objectives. This will require
more information about region-specific impacts and their implications, and about
landscape processes and features that facilitate persistence and adaptability of
biodiversity. A richer body of science-policy knowledge is required to enable
managers to determine and seek the information that will be useful to them, and
to help researchers develop analysis tools and monitoring. Managers will also need
more knowledge and tools to help them balance worthy but competing demands.
Finally, we will need more understanding and better tools to help us deal with
uncertainty.
Conclusions and implications for the NRS
This project showed that climate change is likely to lead to very significant and
widespread ecological impacts. Although spatial environmental heterogeneity may
help buffer the impact for some species, the buffering will vary regionally. There
will be many threats to biodiversity, including alien species, altered fire regimes, and
human uses of land and water due to adaptation in other sectors. As a result, we will
need to reassess our conservation objectives, understanding that biodiversity and
our biodiversity values will change. We will also need to consider regional social and
ecological factors when developing management approaches, and these approaches
will need to be robust in the face of high levels of uncertainty. The NRS is such a
robust strategy, maintaining representativeness even in the face of climate change,
but management of protected areas and landscapes will need to be adapted and
revised over time. Gaps in science, management and policy knowledge and tools
were identified, which will help direct management and research development.
Record Information
- Source Institution:
- Florida International University
- Rights Management:
- Please contact the owning institution for licensing and permissions. It is the user's responsibility to ensure use does not violate any third party rights.
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