Research On Degenerated Mechanism For Haloxylon Ammodendron In Ganjiahu Nature Reserve Of Xinjiang

Haloxylon ammodendron community is Xinjiang Ganjiahu National NatureReserve of the reserve, it plays an important role in the sand prevention andstabilization of sands. But in recent years, the phenomenon of serious degradation ofHaloxylon ammodendron, many plants will die, a large area of land desertification,the reasons causing this phenomenon to explore. Therefore, this paper throughon-the-spot investigation of Haloxylon ammodendron Forest Nature Reserve inGanjiahu National, from three levels of different functional areas, different types ofinterference and different degradation degree, studying in the population ofcharacteristics of Haloxylon ammodendron, the soil physical and chemical properties,human disturbance characteristics, interference characteristics of damage by gerbil,seek the mechanism of degeneration for Ganjiahu nature protection area of Haloxylonammodendron, provided important basis of ecological protection and restoration forthe study area, perfected the arid desert ecosystem restoration and reconstruction ofthe theory and practice Conclusions of the study are as follows:(1) Degraded natural factors for Haloxylon ammodendron:1)2010May to2012October, group went to the study area for6times, thoughestablishment sample collecting soil samples, reaching from experimented on soilparticle size and chemical properties in the laboratory some conclusion:Soil particlesize is generally big, in the different functional areas, different levels of disturbance.Soil particle size has certain regularity: the average particle size of core soil <buffer<test zones;soil particle diameter in the serious damage by gerbil> heavy grazing area> not disturbed area; Soil salt content is higher, the majority of serious salt marshareas in the study area, haven significantly less salt crust; Soil organic matter contentis less,the average level only0.77.4%, soil being barren; Soil enzyme content is alsoless commonly, the content of soil enzyme decreased with soil depth;Soildegradation phenomenon obviously, and more serious soil degradation, the seriousdegradation of Haloxylon ammodendron.2)Based on investigation and analysis of the characteristics of Haloxylonammodendron populations in the single population was found: Single vegetationspecies in the study area, stand relatively sparse, individual large, the average heightbetween2.8m to3.5m; Average the crown is small, average crown only1.87m2,individual branches overlap less, clumped distribution. In addition, there are a lot ofHaloxylon ammodendron dead isolated in the study area, presented the serious trend of Haloxylon ammodendron degeneration.3)Use of photosynthesis under the type and extent of different disturbance,measured by the photosynthetic rate of Haloxylon ammodendron in daily differenttime difference. All kind of Haloxylon ammodendron in every day at13noon to15,photosynthetic rate curve is the bottom,each appeared a peak; In the14or so, therewill be midday depression of photosynthesis and transpiration midday depression. Inthe different levels of interference, the average optical of Haloxylon ammodendron inthe same moment photosynthetic rate were significantly different: no interferencezone of Haloxylon ammodendron average photosynthetic rate> the area in the seriousdamage by gerbil> sandy land.4)The results for on-the-spot investigation and research in the study area:Haloxylon ammodendron has serious plant diseases and insect pests, especiallydamage by gerbil.In the serious regional of damage by mice, there are more ofHaloxylon ammodendron plants died and dead branches, low of individual activity,serious of soil degradation trend, so that Haloxylon ammodendron degenerationphenomenon is significant.(2)Degraded man-made factors for Haloxylon ammodendronHuman disturbance factors, directly and indirectly affect the degradation degreeof Haloxylon ammodendron。According to statistics, from50s to2010, the originalSuoSuoLin area is reduced by4466.67km2to4466.67km2, shrink ratio reached77.12%. On the one hand artificial reclamation and felling Haloxylon ammodendronwoods, enlarged the scope of human activities, reduced the parasitization of livingspace, as a direct result of Haloxylon ammodendron woods the decrease of the area,Haloxylon ammodendron degradation degree increasing; On the one hand, theincrease of land area, irrigation water and ecological water use of competition andcause lower underground water level, water can’t meet the growth of Haloxylonammodendron, Haloxylon ammodendron gradually withered dead, further intensifythe degradation degree of Haloxylon ammodendron; Farming, deforestation and, onthe other hand, human activities, such as grazing changed the cable of woodland soilphysical and chemical properties, and combined with the long-term wind erosion, theoriginal forest land soil degradation, exacerbating Haloxylon ammodendrondegradation.