Recently in Ecology Category
This problem is hardly new, I think. Although the author did mention that the rapidly increasing foreign trade ports and airports in China makes the control of imported horticulture products more difficult. Apparently, species emigration and immigration happens at the same time on both borders. This is a new challenge to biodiversity conservation, and perhaps a result of globalisation. The problem is as old as trade itself, but nowadays at a completely different scale. Impact can be limited, though, if both sides take actions.
This week's Nature has a news article on Antarctic species threatened by increasing sea water temperature and invasive species utilising the new niche created by this high temperature. In this instance sea water temperature as a slow variable is indirectly controlled by the fast variable: the carbon emission. The system may flip to another state in which the previous ecosystem will be essentially eliminated. In this sense the change is irreversible.
A similar effect will be observed in other systems, perhaps in a more subtle way. The resilience theory suggests that such changes in slow variables may generate sudden changes in fast variables. In most natural systems this will manifest itself as loss of niches, habitats and species. As reverting a slow variable is also difficult, this can be considered as loss of these system's resilience. To preserve current state, measures maintaining the fast variables or reverting their changes are possible, yet to preserve resilience, the slow variable must be restored.
This is half a month old but seems not many in the blogsphere take notice in this yet. It is common phenomenon that conservation efforts (and budgets) are mostly given to cute animals. But let's face this, the most ecologically important species are not necessarily appealing to us human.
On 31st January the Independent composed a (not complete) list of species which are at the brink of distinction and needs more attention.
Below are some illustrated descriptions of these ugly-but-need-care species. Without other specification, the photos are from Wikimedia Commons .
Informed multi-objective decision-making in environmental management using Pareto optimality
Multi-objective decision making has been the feature of many environmental management cases, yet there is no effective solutions to optimisation problems with multiple objectives. This article proposes non-dominated Pareto optimisation and an evolutionary algorithm that can approximate the non-dominated Pareto frontier. A case study is provided.
The problem seems to be the spatial complexity, which is especially announced in environmental studies, as well as the algorithm’s intrinsic complexity. One assumption of this algorithm that cannot be ignored is that approximation to optimised decisions will produce results approximate to the optimised result, which may not always be valid in the non-linear world.
The result space is potentially very large and needs to be reduced to a few decision alternatives that can be understood and chosen from by the decision-maker.
Despite all these possible caveats, this algorithm seems to be in the right direction towards a more holistic assessment and making of environment decisions. And potentially similar ideas can be applied in my research.
BBC NEWS | World | Americas | Biofuels ‘crime against humanity’
There is yet another voice to express the concerns behind the large scale adoption of biofuel crops, especially corn. It has been pointed out by Mr Ziegler that plantation of biofuel crops has already led to decrease of available arable land, and the increase of food price.
This seems to be one thing that market cannot solve satisfyingly. If we rely solely on price and demand to adjust the production of food and biofuel, it can be expected that farmers will always have incentives to plant corn to produce ethanol before the price of biofuel is the same as fossil fuel. At the same time food price will also rise and leave more people in hunger. But farmers will not turn to food production until food price (combined with subsidies, maybe) is high enough to provide revenue as good as fuel. By then millions would have starved.
A threshold should be determined which states the maximum land and other resources allocated to biofuel production and should be enforced as a law. If we cannot determine the threshold yet, I think it is another time to apply precaution principle and set a safe limit. At the same time attempts to reduce fuel consumption and improve fuel efficiency should always be encouraged.
On the other hand, Food and Agriculture Organization in 2005 considered biofuel as a key to fight against hunger, as it reduces the import bill as well as brings investments and jobs. But that argument seems to miss the resource part, ignoring food production while it examines hunger.
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Today I attended a lecture given by Alan Bullin with the topic “Biofuels in the Asia-Pacific”, which is just a general review of the situation of biofuel legislation, adoption and application in developed and developing world. But my question would be, how biofuel crops affect the resilience of farmers who adopted them out of economic interest?
I asked this because I thought of farmers in China. If they know this is going to make money you can bet they will begin to plant sugarcanes overnight. However, their relatively slow rate to access relevant information means they are very likely to encounter market failures and have losses. On the other hand, the question is also about long-term perspectives. If one day we suddenly do not need biofuel and fossil fuels anymore (invention of safe and cheap hydrogen/nuclear/solar/you-name-it energy technologies), will the farmers be able to quickly and easily turn to other income sources?
Dr. Bullin’s answer to the questions, as I perceived, is that the market will determine what the farmers plant, the adoption of new energy will not be sudden, but a gradual process. The competition between various biofuel crops means the farmers will not be trapped in one crop and cannot get themselves out. They can always turn to another kind of biofuel. Of course, in the market, there is always risk.
I did not mention resilience or China’s immature market in my question, which may change his answer a bit. On a second thought, the farmers may not always have alternatives due to climate and hydrology restrictions. I still would like to know whether farmers can turn their sugar cane field into, say, potato garden quickly enough. There have already been some studies on biofuels and resilience. Many of them expressed optimistic evaluation of this new technology concerning long-term gains and resilience, stating their positive role in the conservation of forest and reduction of carbon. However, I do think there is some negative issues that should be scrutinised carefully, for example, increased food price [1], changed land use and threat to natural area/food production [2], and Fairtrade concerns.
- Kill king corn. Nature 449, 637 doi: 10.1038/449637a (2007).
- Fuelling controversy — can biofuels slow the speed of climate change?
[Grassland species loss resulting from reduced niche dimension](http://www.nature.com/nature/journal/v446/n7137/abs/nature05684.html)
The idea of niche dimensionality is an analogy of ``space'' concept -- that the niche space is defined and separated by a series of ecological factors and their values. More such dimensions means that more subspaces or niches can be defined therefore more species may be supported.
Resource addition can make some limiting factors not limiting anymore, allowing fewer trade-off opportunities and thus reduce the dimensions of the niche space. Increased supplies of limiting resources can also change the [stoichiometry](http://www.m-w.com/cgi-bin/dictionary?va=stoichiometry) or decrease the heterogeneity of limiting resources.
The increase of resources does create new niches. However, most local species cannot occupy these new niches. Thus local species number and evenness both decline. The more the species are co-limited by multiple resources, the more likely they will be influenced in the face of diminishing limiting factors.
This concept can be considered as a formalised explanation of the effects of eutrophication. Traditionally eutrophication is interpreted as encouraging nutrient-demanding species so they outcompete those oligotrophic species. The notion of niche dimension provided us with a new perspective.
The question: is there other management actions other than increasing nutrient that can reduce niche dimensions? A guess is that any management that turns limiting factors to unlimiting ones may do so. Will the prohibition of grazing have the same effect on the grassland? It has been observed that biodiversity is higher in grazed plots than nongrazed plots (e.g. [(Taddese et al., 2002)](http://www.springerlink.com/content/vn024bc60xqrg2ca/)).
I came upon this interesting article this morning. The grassland ecosystem has two or more alternative states and the transitions between these states are often difficult. Grazing pressure and water condition to a large extent controls the states of vegetation. As the left figure shows, the control is non-linear. Between grazing pressure Fc and Fr, the system is in an alternative stable state. By making the system wetter, as the right figure shows, we may be able to increase Fc and Fr so the recovery will be easier. Thus the author suggested that during El Niño which brings considerable precipitation maybe we can make the system go to the high biomass state by controlling grazing. However, field experiment will be needed to determine Fr.
WILDLIFE CONSERVATION: River Dolphins Down for the Count, and Perhaps Out -- Guo 314 (5807): 1860 -- Science
We have heard too many sad news and we are getting adapted to it. However, the lost of Baiji again proved the importance of proper environmental management and the necessity of a lobby group for endangered wildlife.
The lost of Baiji is less a ecological problem than a decision-making problem. It is a fact that Baiji is living in one of the world's busiest water channel. The pollution and traffic disturbance were severe, but these causes along cannot kill it. Similarly, fisherman given enough regulation cannot kill it. The extinction of Baiji, is in fact the result of neglect. Though listed as the country's Category I endangered wildlife, its name has not appeared on any media for too long. Nobody really cared the survival of such aquatic mammals in a China's river. As a result, no new policies concerning the conservation of Baiji has been made in recent years. Lack of policies leads to deterioration of water quality, overfishing, river congestion and finally the extinction.
Giant Panda, which has far worse adaptability of environment, has survived in population-dense Sichuan province throughout the years. The big difference is its much more extensive media coverage and powerful lobby groups (perhaps including the policy makers themselves). It can be argued that terrestrial mammals are easier to save by artificial efforts than aquatic ones, but no favourable policies has given to Baiji in the last decade or so.
If there were powerful voices about the conservation of Baiji, the story will be different. Therefore, with limited resources, the existence of lobby groups can determine the survival or extinction of certain species. But of course this does not mean with enough lobby groups everything can be conserved. Looking at the extinction of Baiji and the survival of Giant Panda, it is a serious problem all environmentalists should ask: which species should be conserved, and how?
BBC NEWS | World | South Asia | India and China in warming study
This is a joint effort of two countries to study the effect of global warming on glaciers in Himalaya/Hindu Kush region. The melt of glaciers in this area is expected to bring flood to River Brahmaputra and River Sutlej in short term, and disappearance of the two rivers in a farther future.
The significance of this study is evident: it involves an area that is controlling the climate system in the southern Asia-Pacific region and a large portion of world's population. It is also the only large scale charting survey of the area in about 100 years. It can be expected that the study will provide evidence of climate change and perhaps raise people's awareness of global warming crisis. However, I cannot deduce any further meanings from the information I have. A study providing an action plan may be more suitable. This requires more information on the area's demographical and ecological data so as to identify human activities' effect on the system. My current research is not directly related to this idea but my experience from it may help me in future in similar projects.
The composition of the expedition team is not told in this story, but I hope they have ecologists and human geographers in the team as well as physical geographers.
