Wednesday, June 6, 2012

Intecol 9, Day 2




Dr. Brij Gopal spoke about the experiences from Wetland conservation in India. He pointed out that human dependence on wetlands has been highest in the tropical and subtropical regions, and that wetland restoration for waterfowl, although a recent trend in Europe and the U.S. occurred already in the 10th century. Sri Lanka has more than 10 000 human made water reservoirs that can be seen as artificial wetlands. In India wetlands first became known as a nuisance to human health during the British colonization. He voiced criticism against how the Ramsar convention is followed, since countries who have signed the convention has pledged to also conserve wetlands that they have not listed as Ramsar sites, and this is not occurring.

Dr. Karin Kattenring had an interesting presentation about the problem of a European genotype of Phragmites australis that has become invasive in the U.S., although Phragmites australis is indeed a problem in European wetlands as well. Genetic analysis shows that the species although capable of spreading clonaly is spreading sexually at their site. They have found that the viability of the seeds is linked to cross fertilization, and they are now attempting a conservation strategy by spraying Glycophosphate (The thing in Roundup) on Phragmites australis to reduce the population, and thereby the genetic diversity, which should make the seeds less viable. Personally the idea of spraying Glycophosphate in a wetland is not very appealing to me, but there are indeed culture differences between Europe and the. U.S. when it comes to conservation and restoration (we don´t get to play with flame throwers for example). Dr. Kattering told about that she introduced Phragmites australis into a wetland for an important experiment, and brought down a lot of laughter when she added. “Yes, I admit, we did introduce Phragmites australis into a wetland, and I don´t always sleep very well when I think about it.”

Dr. Chris Joyce spoke about the effects of rewetting as a part of the E.U. agri-environmental schemes, and his groups results show that sedges benefited from rewetting, and that the change in hydrology had a much higher influence than management regime.

Dr. David Growing and Professor Norbert Hölzel both presented information about restoration of wet grasslands, were Growings experience showed that restorations should be done several years in a row to avoid to high founder effects which sounds logical. Hölzel was of a different opinion as he presented results that showed that seeds that don´t germinate the first year after top-soil removal with subsequent hay-transfer often germinate the following years. A discussion about the invasiveness about top-soil removal followed, since it is not very common in the U.S. It should be said though, that in sites were the nitrogen level, the phosphorous level and the unwanted seed bank is high, and the water table is to low, then top-soil removal is a good way to restore both wet grasslands and fens. Compared to rewetting it also releases far less methane emission as Lukasz Kozub´s poster at this conference showed. It is however a method that is invasive (you do not conserve the soil), and expensive. 

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