Home Mission 2007 Team Members Research Sources Progress Journal	What are the impacts of oil exploration and drilling on ANWR producers (vegetation and certain botanic species)? 1.    Sedges and willows for nutrition There are two major types of plants that are very important in providing the herbivores (caribou, muskoxen, etc) with high quality and nutritious food: tussock cottongrass (Eriophorum vaginatum) and diamond-leaf willow (Salix planifolia ssp. pulchra). Surveys by US Geological Survey have shown that disturbed areas by petroleum development in other parts of Alaska exhibit significant decreasing quantity and quality of these two plants. In disturbed areas, they have lower biomass, lower nutritional values and higher fiber and lignin concentrations which decrease digestibility. This in turn significantly adversely affects reproduction and calving success of caribou that highly depend on them. See:    http://www.absc.usgs.gov/1002/section5.htm 2.    Sedges and willows for inhabitation Willows in riparian areas are important nesting habitat for migratory birds. Willows will be reduced in amount by heavy tracked vehicles for seismic studies. They will also be affected in the long term by thawing of permafrost, which would be discussed in greater details in the latter part of this essay. Loss of nesting places means unsuccessful calving for birds and higher chances of predation. Successful rehabilitation techniques are yet to be developed for these areas. See:    http://www.worldwildlife.org/arctic-refuge/anwr_position.pdf 3.    Mosses and lichens for nutrition While sedges and willows are important food source for herbivores during summer, the growing and calving seasons, mosses and lichens are more important for local herbivores during the bitter winter as they can still grow well during the winter, though they have lower nutritional values. Construction of drilling site, roads and tracked vehicles all directly destroys the delicate mosses and lichens, lowering the energy source for the herbivores such as muskoxen. Read:    Ecology of Arctic Environment (Edited by Sarah J. Woodin & Mick Marquiss) 4.    Mosses and lichens for carbon and nutrient cycling Mosses and lichens have a major influence on nutrient cycling in tundra and other northern ecosystems through their role in nitrogen fixation, and the ability of mosses to accumulate and retain elements from precipitation. They restrict the draining away of nutrients and help trap them during the summer and avail the nutrient for the herbivores during the winter. Slow decomposition of mosses allows the mosses to contribute significantly to the Arctic carbon sink. By photosynthesis, they "fix" carbon from the atmosphere to organic compounds and by slow decomposition they help trap the carbon instead quickly releasing them back to the atmosphere. This helps soothing global warming. Destruction means that all these functions cannot carry on. Read:    Ecology of Arctic Environment (Edited by Sarah J. Woodin & Mick Marquiss) 5.    Mosses and lichens on maintaining the permafrost Mosses and their under-composed remains are particularly efficient in thermal insulation when dry, thus restricting heat penetration into arctic soils in summer. Thermocarst resulting from destruction of the vegetation by the summer use of tracked vehicles during early stages of arctic oil exploration demonstrated the importance of the moss layer in maintaining permafrost. This caused extensive thawing of permafrost. The importance of permafrost on arctic ecology will be discussed in the next paragraphs.     Read:    Ecology of Arctic Environment (Edited by Sarah J. Woodin & Mick Marquiss) 6.    Permafrost Permafrost layer restricts the drainage of water through the soil, making it moist in the short summer growing season. It is easily broken by road construction or the seismic explosions used in oil exploration, changing the water drainage patterns of the soil and thus retention of moisture. Melting permafrost has also led to widespread damage of buildings, costly road repairs, and increased maintenance for pipelines and other infrastructure – impacts that will continue to grow in magnitude. Permafrost also stores large amount of ancient carbon and methane; thawing is likely to release some of this stored carbon and methane back into the atmosphere, amplifying the risk of further climate change. The boreal forest will advance northward into present coastal plain tundra, and mixed forest into present boreal forest. Forest fires and insect outbreaks, both of which have increased sharply in recent years, will further increase. If the permafrost thaws, the vegetation will in the long term dries out, altering plant communities and use by wildlife. IMPORTANT:    It has been observed that in areas where the permafrost thaws, there is a sudden rapid growth of plants, which attract more animals to feed on. However, this is only momentary. Once the permafrost thaws, temporarily there is much water for plants to grow well for like a month or two, but then the water is continuously used up and drained away as there is no layer to prevention drainage now; yet the permafrost, once destroyed, take years to resume. Therefore, a few months after destruction, water will finally be deficient and no plants can grow well even during summer when water has already been used up, drained away but no permafrost exists to trap them for the growing season. This detrimental effect on vegetation is permanent, while the vast growth of plants is just transient. See:    http://www.ucsusa.org/global_environment/archive/page.cfm?pageID=780 Summary: “The effects of winter seismic trails on tundra vegetation were studied on the Coastal Plain of the Arctic National Wildlife Refuge. Plant cover was lower on most disturbed plots than on their adjacent controls, with decreases as high as 87% the first summer following disturbance. The species most sensitive to disturbance were evergreen shrubs, followed by willows, tussock sedges, and lichens. Willow height in riparian shrubland plots was significantly reduced by 5 to 11 cm (from an average of 16 cm, p < 0.05). Little recovery of plants occurred in the second or third summers after disturbance; only four plots in river floodplain habitats (Dryas terrace and riparian shrubland) showed improvements in cover of a few species.” (From http://www.csa.com/hottopics/ern/01aug/01aug16.html) By Amos Tai
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