Spatial pattern changes of biomass, litterfall and coverage with environmental factors across temperate grassland subjected to various management practices

Understanding the influences of different utilization patterns in different grassland types on grassland traits is essential for grassland conservation and improvement of grassland management. Grazing, mowing, and fencing have the potential to substantially affect vegetation characteristics. The general pattern and mechanisms for relationships between vegetation characteristics and abiotic factors are fundamental issues in ecology .The effect of the key factors on vegetation traits under different management practices has been rarely comprehensively elucidated in previous studies,especially across the temperate grasslands in the Hulunbuir region. Therefore, the principal purposes of this study were: (1) to analyze the effects of different management practices on vegetation characteristics using data investigated from 23 sites across the temperate grasslands; (2) to explore the relationship of environmental factors with vegetation dynamics, and to identify the main factors using correlation analysis; and (3) to predict the evolution of vegetation dynamics with the major factors using the generalized additive modelat the landscape scale. The study area is situated at the western part of Mt. Daxing'anling, Hulunbuir, Inner Mongolia, China. Samples were collected in the grasslands utilized for grazing (always from 10 sampled sites), mowing (since 2003, from 6 sampled sites), and fencing (since 2003, from 7 samples sites). In each site, we investigated above ground biomass, below ground, litter, coverage and soil properties in five plots (1 m x 1 m) at a 10 m interval along a transect. Data pertaining to the environmental factors and vegetation characteristics in different utilization types were compared using ANOVA. The relationship of the main elements with vegetation traits was analyzed using CA in these utilization types. GAM analysis was conducted to explore the evolutionary trend of vegetation dynamics with respect to the critical factors at the landscape scale. Fencing and mowing practices, which can improve vegetation traits, and increase grassland carbon sink, should be continued to promote the Hulunbuir grasslands, rather than grazing management. Thus, appropriate reforms concerning the proper utilize the grassland (e.g. mowing and fencing) is necessary to ensure sustainability of the grassland ecological system, and what is more, the effects of the ecological project in the sustainable development of the temperate grasslands in the Hulunbuir region should be gradually explored.