Our discussion of this paper started us thinking about how useful the BDEF relationship is to ecology, conservation, and restoration ecology. We concluded first that the demonstration that biodiversity loss can impact ecosystem function justified what many of us do (try to understand spatio-temporal patterns in biodiversity in its various forms). Second, we discussed the notion that given that much of conservation applies to rare species conservation and the removal of rare species (e.g., the flightless New Zealand takahē (Porphyrio hochstetteri), decline in tussock grasslands of the South Island), doesn’t appear to affect the functioning of their native ecosystem, is it something that conservationists need to know or worry about? We concluded that the BDEF research was most relevant to restoration ecology where practitioners should want to know about the ecosystem-level effects of their efforts. We talked about integrating different measures of diversity and multiple ecosystem functions into our monitoring of restoration success.
We then moved on to a discussion of differences between ecosystem functions and ecosystem services and how these things might be measured in a restoration context. We talked about the effect of scale on evaluating restoration success, what restoration success was in general and what questions we needed answers to in order to make ‘recommendations’ to land managers who wanted advice on restoring a given area of land. We also debated the constraints on our ability to feed everyone on Earth now and into the future.
Questions:
· We started to talk about how we would measure things in a real system, such as a restoration experiment, but it would be worthwhile to think more about this. How can ecosystem functions be measured? How can ecosystem services be measured?
· Several other recent review papers were suggested to be relevant to our debate including Cardinale et al. (2012), Ehrlich et al (2012), and Hooper et al. (2012). How are these differ from the Naeem et al. paper?
References cited
Cardinale, et al. 2012. Biodiversity loss and its impact on humanity. Nature 486: 59-67.
Ehrlich et al. 2012. Securing natural capital and expanding equity to rescale civilization. Nature 486: 68-73.
Hooper et al. 2012. A global synthesis reveals biodiversity loss as a major driver of ecosystem change. Nature 486: 105-109.
Naeem et al. 2012. The functions of biological diversity in an age of extinction. Science 336: 1401-1406.
Many species targeted for conservation, such as the takahē (do we really know their role?), may not have a large impact on ecosystem functions but are of cultural value and can be seen as an ecosystem service. Naeem et al. (2012) believes that “Nothing in biodiversity and ecosystem functioning research should dissuade conservation from its efforts to bring our age of extinction to a halt”. Of course as was discussed everyone has different value judgments and there is the reality of political will and funding availability.
ReplyDeleteThe article by Cardinale et al. (2012) was published in Nature in the same month as the Naeem article and also discusses the effects of biodiversity loss on ecosystem functions and services. They also sum up work done in the last 20 years and come up with 4 major trends.
1. The impacts of diversity loss on ecological processes might be sufficiently large to rival the impacts of many other global drivers of environmental change.
2. Diversity effects grow stronger with time, and may increase at larger spatial scales.
3. Maintaining multiple ecosystem processes at multiple places and times requires higher levels of biodiversity than does a single process at a single place and time
4. The ecological consequences of biodiversity loss can be predicted from evolutionary history.
Both articles and their associated cited literature paint a clear picture of the importance of diversity to the functioning of ecosystems and in turn the ability of these systems to maintain ecosystem services that benefit humanity. Our discussion on BDEF led to a debate on the ability to feed an ever increasing human population and the best use of land. Do we have enough productive land to provide food now and into the future? With an increase in droughts and flooding through climate change land may become even more marginal for food growing. China is trying to address these problems by establishing a network of ‘ecosystem function conservation areas’ (EFCAs). These areas are to focus on conservation and restoration with the aim to protect ecosystems and their biodiversity for flood control, irrigation, more production and sustainable land-use practices (Ehrlich et al. 2012). Hooper et al. (2012) suggested that biodiversity loss in the 21st century could rank among the major drivers of ecosystem change such as global warming, ozone depletion and acidification of the oceans. Can biodiversity and ecosystem functioning research give us practical solutions to the problems of biodiversity loss?
From the readings and Denise´s comment, I consider that another challenge would be to determine how to reinforce this non-utilitarian or cultural value that Naeem et al. discuss and how to evaluate it as an ecosystem service, for in my experience is less considered when political/economic decisions are taken for it is non-profitable or not as profitable as other activities.
DeleteAn interesting point Elisa, I almost see an analogy here to the way in that saving a species was not 'valued' until the EF/ES idea came along. Is it less considered? Well culture was certainly included in the Millenium Ecosystem Assessment, where it was defined as "six main types of cultural and amenity services provided by ecosystems: cultural diversity and identity; cultural landscapes and heritage values; spiritual services; inspiration (such as for arts and folklore); aesthetics; and recreation and tourism." (MEA, Ecosystems and human well-being: synthesis, 2005). However, as you say how does it rank in the decision/policy process?
DeleteWell perhaps this is where we come back to Hannah's first question above? Perhaps it is worth looking again at the MEA publications, in particular there is one report called "A framework for assessment". You can dowload the seperate sections as a pdf and they give some nice suggestions as to how to incorporate the different (conflicting?) ESs. Whether this will solve the profit $ issue....well ;)
This does emphasise that conservation biology and ecology are quite different areas with different goals. Ecology is about understanding the processes that drive the ecosystem (and individual species often just contribute variation or noise) whereas Conservation Biology is much more focussed on this noise and less so on the overall process. There has been a push to integrate conservation and ecology for the last few years but I wonder just how productive that might be....
ReplyDeleteThanks for your comment Roddy. I've put a link to one of the MEA documents on the course website for students, or you can find it here: http://www.maweb.org/en/index.aspx
ReplyDelete