Study On The Degradation Status Of Herdsmen Grazing Pastures In Typical Steep

Grassland ecosystem degradation has always been an objective problem in the harmonious development of human-land relations.The contradiction between herdsmen's production and living needs and the grassland ecological environment has become increasingly prominent,then a series of environmental problems derived from it have been one of the problems that plagued China and even the global ecological environment construction.Therefore,how to control grassland degradation is an urgent problem to be solved in China's ecological environment construction.The typical steep of Inner Mongolia is an important ecological barrier in northern China.The ecological environment is fragile and complex.Driven by policies,grassland management and utilization methods have changed from nomadic to net fence rotation grazing.The research area Alatantao Gaotu Gacha is located in Narenbao Lagsumu,north of the Abaga Banner in Xilinguole League,Inner Mongolia.It is a characteristic of the pastoral area that borders Mongolia.Assessing the degradation of household grasslands is conducive to more scientific and rational planning and utilization of grassland grassland resources by herdsmen.In this paper,the research area of Alatantaogatu Gacha in the northern part of Abaga Flag,Xilingol League,Inner Mongolia was used as the research area.Winter pastures of 4 herders(such as herder NR,herder AL,herder BL and herder CG)in the study area and a pasture that has been enclosed for nearly ten years(called enclosure grassland FB)were selected as the research objects of this paper.Among them,the natural background and environment of the four herdsmen are consistent.Under the current conditions of the herdsmen,the two-season rotation grazing are adopted.The statistical results in the past three years show that the grazing intensity of the four herdsmen has shown a clear gap,the details are as follows:enclosure FB(0Yangdanwei/hm~2);herdsman NR(0.84 Yangdanwei/hm~2);herdsmen AL(1.74 Yangdanwei/hm~2);herdsmen BL(1.01 Yangdanwei/hm~2);herdsmen CG(1.46 Yangdanwei/hm~2).The field sampling and herder interviews were used to obtain basic survey data.Based on the above background,various mathematical statistical analysis methods were comprehensively used to analyze four herders and one enclosure in Gacha Based on the data of related plants and soil in the grassland,the degree of degradation of the grassland of different herders was calculated by the CVOR model.The grassland degradation level is mainly determined through the evaluation of grassland health and the comprehensive classification of plant communities.Finally,analyze the causes of grassland degradation through the survey data.The main results and conclusions of this study are summarized as follows:(1)The grazing method has an important impact on the degradation of herding pastures.At present,the herdsmen in Alatengtaogaotu Gacha mostly adopt the method of settling rotation grazing.Under the restriction of the net fence,the herds are eating in a limited area.Compared with the traditional nomadic method,the frequency of herding of grassland is significantly increased,and the grassland is prone to block degradation under the settlement grazing method.At present,the herdsmen in Gacha mostly adopt the method of settling rotation grazing.Since the settlement of grazing in the 1980s,the NDVI value in Gacha has shown a clear downward trend.From the herdsmen's result of M.Gordon stability index,the stability of the herdsmen's pastures surveyed is at a low level.(2)Grazing intensity has a driving effect on the degradation of herding pastures.The grazing intensity of the herdsmen surveyed in the past three years is quite different,and the specific performance is as follows:FB<herdsman NR<herdsman CG<herdsman BL<herdsman AL.The herder at lower grazing intensity like FB and Herders NR are at a higher level in indicators such as plant community structure,diversity index,stability index,and soil physical and chemical properties.The related indicators of other herdsmen AL,BL and CG are significantly lower than the previous herdsmen.The plant classification results of principal component analysis(PCA),non-metric multidimensional calibration(NMDS),and two-way indicator species analysis(TWINSPAN)also show that there are obvious gaps in plant communities between different herdsmen.The main species of FB are Stipa grandis+Leymus chinensis+Cleistogenes squarrosa;the plant communities of herdsmen NR and AL are Stipa krylovii+Chenopodium glaucum+Allium tenuissimum;the main species of herdsmen AL are Stipa krylovii+Chenopodium glaucum+Allium tenuissimum,and herder CG are Allium polyrhizum+Carex duriuscula.The results of the CVOR health evaluation of the pastoral pastures roughly correspond to their grazing intensity.The specific performance is as follows:BL(alert)<herdsman CG(sub-health)<herdsman AL(sub-health)<FB(health)<herdsman NR(health).According to the classification results of pastoral pasture plant energy communities,the degree of pastoral grassland degradation can be divided into three major categories:light degradation(herdsman NR and FB),moderate degradation(herdsman AL),and severe degradation(herdsmen BL and herdsmen CG),grazing pastures of various herdsmen have been degraded to varying degrees.On the whole,in addition to the serious grassland vegetation and soil degradation caused by annual overgrazing by herdsmen BL in this study,the grassland degradation of herdsmen is mainly manifested by the reverse succession of plant communities,and the degree of soil degradation is relatively light.Some moderately and severely degraded pastures implement short-term enclosures to utilize the self-healing function of the pasture ecosystem to improve the degradation status of the pastures.Meanwhile,some severely degraded pastures can also take appropriate biological measures to improve the self-healing ability of the pastures.Moreover,FB has been evaluation for many years,but the result shows it is failed to widen the gap with herdsmen NR,which demonstrate that fencing management can only be used as a short-term measure for grassland degradation management.Sustainable development still has a long way to go.