Exploiting pattern and sustainable development of marginal lands in the Three Gorge Reservoir Areas

This paper studied the distribution and utilization status, reasonable exploitation patterns and potential productivity, and sustainable development of marginal lands in the Three Gorge Reservoir Areas. It has been pointed that problems of the soil fertility degradation, poor productivity in crop lands, natural disasters and environmental deterioration existed in all the exploited marginal lands. In order to maintain the sustainability of the marginal lands, following measure have been proposed: prohibiting cultivation in the crop lands with a slope more than 25°, restoring vegetation in the slope more than 25°, strengthening the basic agricultural construction, establishing the production base of woody feeds and oils, establishing a multi dimensional management model with reasonable structure and optimum function for forestry, agriculture and fishing.

Demonstration of reversible retinal ganglion cell dysfunction in inflammatory optic neuropathies utilizing pattern electroretinography

Dear Editor,I am Dr.Austin Bach from Larkin Community Hospital in South Miami,Florida,USA.I am writing to you to present three cases of inflammatory optic neuritis that was followed to resolution using pattern electroretinography（PERG）.

Ecological Status and Uses of Juniper Species in the Cold Desert Environment of the Lahaul Valley, North-western Himalaya, India

The juniper species Juniperus polycarpos C. Koch, J. indica Bertol. and J. communis L. var. saxatilis （Pallas） are important elements of the forest vegetation in Lahaul valley in the north-western Himalaya. Their ability to grow under the barren and xeric conditions of cold deserts makes them particularly suited for afforestation programmes under these eeologieal conditions. In the Lahaul valley, juniper species are used as subsistence resources and for religious purposes. Excessive removal of juniper wood and leaves by the local population, overgrazing, habitat fragmentation and low regeneration potential are the main obstacles to eonservation of juniper forests in this region. The present study was carried out to assess density, basal area and importance value index （WI） of the local vegetation as well as uses and amounts of juniper wood and leaves removed from the local forests. Pressure on relict juniper forests due to grazing animals and intensive removal of wood and leaves by the loeal population was found to be greater at an altitude above 3,00o m. The results of the study demonstrated that the different juniper speeies were adapted to specific altitude ranges. A higher species density was recorded at lower altitude except for J. indica which was only present at high altitude （〉3,200 m） on south-facing slopes. Density, basal area and IVI of J. polycarpos were higher at Hinsa （2,7oo m） than at Jahlma （3,000 m）. The rapid loss of vegetation due to overuse and habitat degradation has made the eonservation of juniper forests an important priority in the Lahaul valley. J. polycarpos at loweraltitude and J. indica at higher altitude are ecologically the more suitable species for the successful implementation of conservation programmes. The support of rehabilitation programmes by regional authorities is essential for the reestablishment of the local juniper forests.

Comparison of ecosystem services provided by grasslands with different utilization patterns in China's Inner Mongolia Autonomous Region

Although several previous studies in Inner Mongolia examined the effects of ecological conservation on the delivery of ecosystem services, they were often limited in scope（few ecosystem services were assessed） and often suffered from confounding by spatial variation. In this study, we examined the impact of conservation measures（changes in grassland utilization patterns） on the provision of selected ecosystem services in three types of grasslands（meadow steppe in Hulun Buir, typical steppe in Xilin Gol, and semi-desert steppe in Ordos） in Inner Mongolia. We examined five utilization patterns： no use（natural grasslands）, light use, moderate use, intensive use, and recovery sites（degraded sites protected from further use）. Through household surveys and vegetation and soil surveys, we measured the differences in ecosystem services among the different grassland utilization patterns. We also identified spatial factors that confounded the quantification of ecosystem services in different types of grasslands. We found that light use generally provided high levels of ecosystem services in meadow steppe and typical steppe, with the main differences in the supporting ecosystem services. Surprisingly, we found no consistently positive impacts of strict conservation activities across the sites, since the results varied spatially and with respect to differences in the land-use patterns. Our study suggests that appropriate grassland utilization patterns can enhance the supply of ecosystem services and reduce negative effects on both household livelihoods and the environment.