Impacts of Mau Forest Catchment on the Great Rift Valley Lakes in Kenya

Remote sensing and GIS applications are being widely used for various projects relating to natural resource management. Forests are very important national assets for economic, environmental protection, social and cultural values and should be conserved in order to realize all these benefits. Kenya’s forests are rapidly declining due to pressure from increased population, technological innovation, urbanization human development and other land uses. Mau forest is one of the major forests in Kenya that is a catchment area for many Great Rift Valley lakes within the country and faces a lot of destruction. Continued destruction of the Mau forest will cause catastrophic environmental damage, resulting in massive food crises and compromising the livelihoods of millions of Kenyans, and the possible collapse of the tourism industry. The purpose of this research was to investigate the relationship between the increasing rate of deforestation and the reduction of the volumes of water in the neighboring lakes between the years 1989 to 2010. Satellite images from Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper (ETM+) were used for the detection of changes in the Mau forest and the dynamics of the neighboring water bodies that included lakes: Naivasha, Baringo, Nakuru, Elementaita and Bogoria. The research showed that from a period of 1989 to 2010 Mau forest has been decreasing due to deforestation and the water bodies have irregular dynamics in that, from 1989 to 2000, there was rise in the volume of water, this is attributed to the El Nino rains experienced in the country during the year 1997 and 1998. But between 2000 and 2010 the volume decreased as the forest is also decreasing. It is recommended that the government creates awareness to sensitize the public on the importance of such forests as catchment areas in Kenya.

SHORT COMMUNICATION Principal-agent Relationships: A Note on Biomass Depletion

Public authorities frequently mandate public or private agencies to manage their renewable natural resources.Contrary to the agency,which is an expert in renewable natural resource management,public authorities usually ignore the sustainable level of harvest.In this note,we first model the contractual relationship between a principal,who owns the renewable natural resource,and an agent,who holds private information on its sustainable level of harvest.We then look for the Pareto-optimal allocations.In the situation of an imperfect information setting,we find that the Pareto-optimal contracting depends on the probability that the harvesting level stands outside the sustainability interval.The information rent held by the agent turns out to be unavoidable,such that stepping outside the sustainability interval implies the possibility of depletion of the renewable natural resource.This,in turn,compromises the maintenance of the ecological balance in natural ecosystems.

Advance agriculture in the desert:the Israeli case story

The Israeli Desert constitutes 60% of the country＇s total area. Regional annual precipitation is 100-200 mm and evapora- tion reaches 2,500 mm. Traditional desert agriculture of rain fed wheat and sheep, goat and camels grazing is common. Despite the harsh climate conditions, advance agriculture is concentrated in foei where water resources exist. Desert ag- riculture takes advantage of the winter （October-April） due to a mild climate season for growing vegetables, flowers, herbs and fruit which are mostly exported to European countries. The key factor is the sustainable management of the local natural resources.

Soil properties characterization for land-use planning and soil management in watersheds under family farming

Environmental monitoring of small,rural watersheds was one of the components of the Natural Re-sources Management and Rural Poverty Alleviation Program(RS-Rural)in southern Brazil.The purpose of the monitoring was to assess the impact of promoting soil conservation and environment manage-ment practices adopted by farmers and funded by the Program.In four small monitored watersheds,in a total of 95 plots representing distinct land use and soil management,surface soil was collected to characterize ground-zero of the Program by determining several soil physical,chemical and microbio-logical properties.Principal component analysis(PCA)shows soil physical,chemical and biological properties were decisive in defining the agricultural soils in the rural watersheds with family farming.The sensitivity to chemical properties provides an opportunity to improve soil quality if soil management focuses on altering those properties.Soil management practiced by tobacco farmers leads to rapid,intense degradation of some natural soil properties,especially those related to the dynamics of soil organic matter,compared with more conservationist uses(forest,regrowth,and grassland).Thus,soil management must be reoriented to avoid the progress of degradation and recover soil physical and biological quality.Cover crops and by land-abandonment to allow natural vegetation are important management strategies for the degraded soils used for tobacco production,increasing soil organic matter,nutrients and microbial activity and thus allowing further crop production.In conclusion,wa-tersheds with tobacco cropping have soils with lower quality than when under no-tillage grain pro-duction,requiring changes in land use and soil management.

不同利用模式下内蒙古自治区草地生态系统服务供给的对比分析（英文）

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.