Joern Fischer on Landscape Patterns & Terrestrial Biodiversity
Emerging Research Fronts Commentary, December 2011
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Article: Landscape modification and habitat fragmentation: a synthesis
Authors: Fischer, J;Lindenmayer, DB |
Joern Fischer talks with ScienceWatch.com and answers a few questions about this month's Emerging Research Front paper in the field of Environment/Ecology.
Why do you think your paper is highly
cited?
Most of the world's terrestrial ecosystems have been modified by people. Working out how to sustainably share land with other species probably is the single biggest challenge for conservation biologists today. The topic of landscape modification and habitat change therefore is of tremendous interest to a large number of ecologists.
Our review differs from previous reviews in two important ways. First, the scope of our paper is very broad, whereas most previous reviews have specifically targeted one or few issues related to landscape modification. Second, we offer a new conceptual framework which brings much needed theoretical clarity into "fragmentation" research. Namely, we distinguish between issues that are relevant from the perspective of understanding individual species versus issues that are relevant for understanding landscape patterns from a human perspective. The broad scope of our paper, plus the conceptual framework, probably make it useful to a large number of readers.
What are the key developments that your review
paper covers?
Our conceptual framework is different from previous work. Specifically, we distinguish between a species perspective and a human perspective of human-modified landscapes. Many scientists regularly mix concepts from these two different perspectives, which has slowed scientific progress and has led to futile debates.
An agricultural landscape in Central Romania.
Low-intensity land use and high landscape heterogeneity have maintained
high biodiversity in this landscape for centuries. Photo credit: Kimberlie
Rawlings.
For example, people have asked whether corridors provide connectivity—which (arguably) is just not a sensible question. The real question should be: what types of corridors, under what conditions, provide which kind of connectivity for which species? Similarly, "habitat" is sometimes used as synonymous with native vegetation. But of course, some species live in human-dominated or even exotic vegetation communities. So, again, we cannot state that "habitat should be conserved," but rather the question is which habitat for which species.
Distinguishing between a human perspective (and landscape patterns) and a species perspective (and associated processes) is a seemingly simple, but very important advance. We review a range of topics from both perspectives.
Would you summarize the significance of your paper
in layman's terms?
We argue that human-modified landscapes are where the future of terrestrial biodiversity will be decided. Protected areas are important, but on their own, they are too small, too isolated, and not safe from large-scale threats such as global warming. We show that there are some landscape patterns that can improve conservation outcomes: high structural complexity and large, well-connected patches of native vegetation, for example.
We also argue that in addition to thinking about such patterns, it is worthwhile to think specifically about the needs of individual species—their habitat requirements, for example, or their interactions with other species. Carefully considering both patterns and processes in human-modified landscapes can improve biodiversity conservation immensely.
How did you become involved in this research, and
how would you describe the particular challenges, setbacks, and
successes that you've encountered along the way?
"I believe interdisciplinary work is essential to solve real-world environmental problems. Of course, it is important to maintain enough disciplinary depth as well."
I conducted this research together with Professor David Lindenmayer, a world leader in conservation biology. David and I had collaborated on several empirical studies that took place in forestry landscapes and farming landscapes. We felt we had gained a lot of insights from our empirical work, and we felt that synthesis of our various insights could be useful. We then decided to write a book on this (subsequently published by Island Press) and also summarize our key messages in this synthesis paper.
One challenge along the way has been that leading journals now often want only quantitative reviews, or meta-analyses. This marginalizes papers like ours, which is essentially a conceptual synthesis rather than a quantitative review. The fact that our paper is still highly cited shows very clearly that there still is a need for good conceptual synthesis papers. It would be nice to see some of the leading journals taking a renewed interest in conceptual review papers, rather than emphasizing quantitative work so much: sometimes a quantitative approach can limit the scope of reviews, or lead to a relatively narrow set of insights.
Where do you see your research leading in the
future?
Biodiversity conservation in human-dominated landscapes cannot happen without people. For this reason, my current research in Romania investigates both ecological and socio-economic issues at the same time (see example). I believe interdisciplinary work is essential to solve real-world environmental problems. Of course, it is important to maintain enough disciplinary depth as well.
Do you foresee any social or political
implications for your research?
Our paper concludes with a set of 10 management priorities for
human-dominated landscapes. These relate to managing landscape patterns as
well as the processes affecting individual species. I believe our list can
be a useful starting point for biodiversity conservation in most
human-dominated landscapes around the world.
Professor Joern Fischer
Leuphana Universität Lüneburg
Lüneburg, Germany
KEYWORDS: CONNECTIVITY, COUNTRYSIDE BIOGEOGRAPHY, EDGE EFFECTS, EXTINCTION PRONENESS, HABITAT LOSS, HABITAT FRAGMENTATION, KEYSTONE PIECES, LANDSCAPE HETEROGENEITY, MATRIX, THREATENING PROCESSES, AUSTRALIAN WHEAT BELT, FOREST FRAGMENTATION, METAPOPULATION DYNAMICS, PATCH SIZE, LAND USE, ECOSYSTEM FRAGMENTATION, POPULATION DYNAMICS.