Small Mammal Study: Environmental Change Impacts on Biodiversity
Sukhbaatar Tsogt, Nyamsuren Batsaikhan and Dandarmaa Bataa
During the recent 10-30 years there was indicated increasing of permafrost ground thawing annual temperature in the mountainous areas of Khuvsgul, Khangai from 0.10 to 0.15°C, thickness of ground stratum is changing from 0.6 to 1.6 cm per a season.
There is being implemented a long-term International co-operated project “Dynamic Research of permafrost ground thawing and biodiversity deficiency in the Hovsgol lake area” with the purpose of investigation of changes in the region. In the frame of this project we are carrying out probes on small mammals’ grouping, quantity and quality changes of some dominated population in the time and environmental different condition, in the furthermore, discovering of their reaction against permafrost ground thawing. Our investigation aims for working up possible management with increasing or decreasing of environmental changes on the base of these researches.
The most important problem of our investigation is searching for the most suitable managment activity implementation in discovering direct or indirect influence of human activity, factors of domestic and wildlife activities, and increasing and decreasing affects and consequence of these activities. On the other hand, permafrost ground thawing gives some requests in investigation of biodiversity, its internal connection and damage for the environment. Small mammals' community is one of the dominant population, so it has some significance role in energy and changing of natural elements, supply of constant ecosystem. Therefore, comparative studies of small mammals in different conditions at the same time can give some possibilties to discover their reaction against the environmental changes, to explain them, to forecast future tendentious. For implementation of this goal there were chosen three valleys near the lake, which can determine the general environmental condition of the area. In these areas were divided into such experimental areas with three different natural zones as steppe, dawn and forest. The field research was hold in 2002-2004 with some durations of plant vegetation from the beginning of June until the beginning of September.
The research occurred on the valleys of three rivers near lake Hovsgol, which geografphical data is similar, but intensity of holding livestock husbandry is different. On these valleys there were registrated number of families and their livestock in 2002, 2003, 2004 and 2005 by the administration of the area with the distantion from the center of the aimag, which is given in the below shown table.
The selection of the area was done by the selectional choice through transectional lines, which are passed all the land space of the investigated valleys, so there were included forest, front sides on the lake bank and the mountains.
The main methodology, which we used in our field experiment was popular technical procedure of the population ecological field investigation "Capture-Mark-Recapture". All collected field and laboratory data were registrated in tables, detailly analyzed, also the collection (skull, bones) was closely examined in the laboratory. Collection of the samples of the investigation was made through the widely used method of folding livetraps of Sherman. On the every selected areas were chosen a square with 100 x 100 m, in each of them were located 100 livetraps, which were put in 10 metres from each other. Trapped bodies individual numbers were marked by amputation of their nails.
The small mammal research results represents:
- Small mammals' diversity shortage is conditioned by degradation and changing of habitat environment;
- Geographical location, population fluctuation of Paleoarctic small mammals has chaotic characters;
- Components of forest community is not depended on population fluctuation. Small mammal population, which live near the riverbank, has asynchronic character.
- Combined factors, which caused by intensive pasture and climate change, becomes as basement for population and geographical location changing;
- Pasture intensity demonstrates role of species in the community, which prefer to live in humidity environment;
- Habitat area of Microtus gregalis determines desiccation process of the area;
- Spreading of species, which prefer living in dry land, can give some possibilities in investigation and monitoring of desiccation process of the area. Based on such investigations there might be appeared ways of sustainable management of forestry zone pasture grazing;
- The most species of northern Cricetidae are active in winter time, which are depended on term and thickness of snow coverage.