Faced with the difficult choice between economic development and environmental conservation, administrators need to evaluate tradeoffs. And Lian Pin Koh, a researcher at the Institute of Terrestrial Ecosystems in Zurich has developed a model that does just that. In an interview with DNA, he explains how it works.
Which is worse — losing a small portion of a forest to oil palm agriculture, or selectively logging a large part of the forest?
Such questions regarding tradeoffs involved in economic development and environmental conservation are being asked with increasing frequency today — especially in Asia, South America and Africa, which are home to pristine forests and are experiencing rapid economic growth at the same time.
Environmental scientists are therefore now trying to figure out where species are most in trouble and where they are relatively secure, since such information allows attention and funds to be focussed in the right places.
To do this, scientists till now have been using the island biogeography theory. Developed in 1967, this theory divides the world into islands of suitable habitats surrounded by a sea of unsuitable habitat. By this logic, lower the area under pristine forest cover, higher the possibility of species going extinct in that area.
One of the main criticisms of this theory stems from the fact that unlike real islands where, say, a land-dwelling deer couldn’t survive in the sea, species such as leopards can survive in pristine forests as well as semi-forest areas.
This prompted Pin Koh to develop a new model which takes into account how sensitive plants and animals are to logged forests, cattle pastures, oil palm plantations and other components of the so-called non-habitat areas (termed ‘matrix’ by ecologists), as he explains in this interview:
Is there suitable data available for the model to work?
The most crucial data that is needed for the model to work concern the sensitivity of plants and animals to each component of the matrix. For example, what percentage of bird species accustomed to living in intact forests would not survive in oil palm plantations?
Fortunately ecologists across the world have been collecting this data for the last few decades. Coincidentally, my colleagues in Singapore and the United States and I have recently begun to gather this data for a different project. Therefore I was able to make use of this data in developing and testing the matrix-calibrated model. Even so, there is always scope for more data to be collected, which would increase the accuracy of the predictions of the model.
In what specific ways can administrators use this model to plan land-use in forest areas? Why were previous models unable to answer questions in this area?
Whereas the conventional species-area relationship could be used to predict extinctions based only on the amount of forest loss, the matrix-calibrated model can now be used to explore the consequences of changes in the entire landscape, including not just the amount of forest but also the quality of the resultant land uses that now comprise the matrix.
Perhaps more importantly, not only will users of the model be able to make more accurate predictions of biodiversity loss from land-use change, they could also use the matrix-calibrated model to predict potential biodiversity enhancements from improvements in the quality of the matrix.
Do you think such a model is more relevant to fast-developing economies such as in Asia where often there is a conflict of interest between conservation & development?
The key to dealing with the conflicts of interest between environmental conservation and development in many emerging economies is the ability to evaluate tradeoffs among different land-use and development options.
Conservationists can now explore questions such as the tradeoffs in biodiversity loss between, say, converting a large part of a forested landscape to extensive but wildlife-friendly agriculture versus converting only some parts of the forest to intensive production systems. These very practical questions could not have been addressed with the conventional species-area relationship.
Can you explain with examples where there is a lack of focus in conservation programmes due to vague data and analysis?
The conventional species-area relationship has a tendency to overestimate species extinctions (because the model assumes the matrix is invariably inhospitable for any plant or animal). While erring on the side of caution may be desirable from a strict conservationist perspective, it may in fact lead to inefficient use of limited conservation resources in terms of manpower and funds.
For example, “biodiversity hotpots” have been identified by conservationists as regions of the world that have the highest conservation priority by virtue of the history of deforestation and biodiversity losses in these areas. However, it is a Herculean task to protect all 34 hotspots that cover over 3 million square kilometres worldwide.
The matrix-calibrated model can help by producing accurate predictions of future threats to biodiversity given certain scenarios of land-use change in each hotspot, and thereby focus conservation resources where they will be most needed.
Considering that we have already lost much of our pristine forest areas, isn’t it better to conserve every acre we can, instead of opening up to developmental activities such as agro forestry?
This is really a philosophical question. The ultimate cause of our environmental problems is the unsustainable rate at which you and I consume natural resources. Short of an ultimate solution, we have to accept that development will proceed, especially in the emerging economies such as Brazil, Indonesia, India and China.
As a scientist, I developed this matrix-calibrated model to be a tool that allows the assessment of tradeoffs in biodiversity among different land-use options, so that policymakers can make more informed decisions. It is, however, civil society that must make those decisions.