The distributions of various forest cover types on Changbai Mountain of northeastern China were examined by interpreting Landsat Thematic Mapper satellite data. The area studied consists of the Changbai Nature Reserve plus an 8 km wide buffer zone. The dominant forest cover types were mixed Korean pine (Pinuskoraiensis Sieb. & Zucc.) hardwood forest below 1100 m above sea level (asl) and evergreen coniferous forest between 1100 and 1650 m asl. These two forest cover types accounted for about 70% of the area inside the reserve, and 50% of the area outside the reserve. Other forest cover types included aspen (Populusdavidiana Dode) –white birch (Betulaplatyphylla Sukachev) forest, hardwood forest, larch (Larixolgensis A. Henry) forest, sparse forest land, and mountain birch (Betulaermanii Cham.) forest. Above the forest line (1950 m asl), a zone of tundra was distributed on the top of Changbai Mountain. The mountain birch forest was located between tundra and the evergreen forest. Human-altered areas, including forest clearcuts and urban areas, accounted for only 10% of the whole study area. More than 90% (in area) of the human-altered areas was found in the zone surrounding the reserve. To better protect the old-growth forest ecosystems inside and outside Changbai Nature Reserve, conservation planning for the reserve and forest management for the surrounding area need to be modified.
a b s t r a c tForest degradation in protected areas has been monitored around the world with remote sensing data, but degradation processes undetectable by widely used satellite sensors have been largely overlooked. Increased human pressures and socioeconomic development make forest protection more challenging, particularly for forest ecosystems that lie across national borders because of the differences in national socioeconomic policies and conditions within them. Here with Landsat data, Google Earth images, and field observations, we show that, in two adjacent biosphere reserves across the border of China and North Korea, over one half of primary forest landscapes have been deteriorated by exploitive uses, including seed harvesting and systematic logging. The combined effects of detectable and hidden degradation processes have further damaged forest ecosystems in the core areas in the two biosphere reserves, threatening sustainable biodiversity conservation in the region. It is urgent to develop cross-border collaborative conservation strategies that can help combat both detectable and hidden degradation processes at a regional scale.
The arcuate nucleus (ARC) in the basal of hypothalamus plays an important role in appetite regulation and energy balance. We sought to investigate the central neuroendocrine mechanism of appetite decrease and weight loss under chronic stress by observing the regulatory effects of Xiaoyaosan decoction in the expression of leptin receptor (ob-R) and neuropeptide Y (NPY) in the ARC. Our results showed that bodyweight and food intake of rats in the 21-day stress group increased slower than those of the normal group. Higher contents of Leptin and ob-R were noted in the 21-day stress group compared with control rats, while NPY expression was not statistically different. Xiaoyaosan powder can significantly downregulate the contents of leptin and ob-R in the hypothalamus of stressed rats. These findings suggest that increase of ob-R expression in the ARC is possibly one key central neuroendocrine change for the somatic discomfort. Weight loss and decreased food intake in rats caused by the binding of leptin to ob-R in hypothalamus do not appear to utilize the NPY pathway. This study also suggests that ob-R in the ARC may act as the target of Xiaoyaosan in regulating the symptoms such as appetite decrease and bodyweight loss under chronic stress.
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