Changing patterns of basic household consumption in the Inner Mongolian grasslands: a case study of policy-oriented adoptive changes in the use of grasslands

Grassland ecosystems, as the basic natural resources in the Inner Mongolia Autonomous Region, are becoming increasingly sensitive to human intervention, leading to deterioration in fragile ecosystems. The goal of this study was to describe the restoration policy-oriented adoptive changes to basic household consumption patterns of food, fuel, and water, and their spatial distribution by grassland types in the region. Basic household consumption data were collected in the meadow steppe (Hulun Buir), typical steppe (Xilin Gol), and semi-desert steppe (Ordos) ecosystems using structured questionnaires administered to 209 herders and farmers. In 2010, the householders' intake comprised a low amount of agricrops, including staple foods, vegetables and fruit with a high amount of meat, which still dominated the patterns of food consumption. However, the number of households preferring this pattern is decreasing and higher amounts of agri-crop and lower amounts of meat consumption pattern is increasing. From 1995 to 2010, fuel consumption patterns changed from being dominated by bio-fuels (dung) to being dominated mainly by electricity and gas. However, bio-fuel remains a major energy source for daily life in the meadow steppe ecosystem. In all three surveyed grassland types, the use of coal, electricity and gas increased from 1995 to 2010. The source of domestic water in all three surveyed areas is from groundwater, with an increasing trend to use tap water from a public supply rather than from privately owned wells

Competition between Keratella cochlearis and Daphnia ambigua: effects of temporal patterns of food supply

SUMMARY. 1. Population growth rates and relative competitive abilities of the rotifer Keratella cochlearis f. tecta and the small‐bodied cladoceran Daphnia ambigua were studied under different schedules of food addition but equal total food quantity (per 4‐day interval). The initial population growth rate of Keratella was significantly affected by the feeding schedule and by the presence of competitors, while that of Daphnia was affected by neither factor. Population densities of both species tended to increase as the frequency of food addition increased. 2. Daphnia suppressed and excluded Keratella from mixed‐species cultures when food was provided intermittently at a high concentration, but it failed to exclude the rotifer when food was provided in a near‐continuous supply at low concentration. Keratella had only a minor suppressive effect on Daphnia in all mixed‐species treatments. 3. Starvation experiments indicate that Daphnia is able to withstand food shortages for significantly longer periods of time than Keratella. These and other results indicate that the outcome of interspecific competition between these species may be influenced by me frequency and concentration at which food is supplied. Daphnia ambigua is competitively superior to K. cochlearis when food is concentrated or ‘pulsed’, but much less so when ambient food levels are chronically low. Patterns of food availability may have important effects in determining the relative abundance of rotifers and small cladocerans in natural zooplankton communities. Copyright © 1991, Wiley Blackwell. All rights reserve