Dataset Information

The Spatial Pattern and Interactions of Woody Plants on the Temperate Savanna of Inner Mongolia, China: The Effects of Alternating Seasonal Grazing-Mowing Regimes.

ABSTRACT: Ulmus pumila tree-dominated temperate savanna, which is distributed widely throughout the forest-steppe ecotone on the Mongolian Plateau, is a relatively stable woody-herbaceous complex ecosystem in northern China. Relatively more attention has been paid to the degradation of typical steppe areas, whereas less focus has been placed on the succession of this typical temperate savanna under the present management regime. In this study, we established 3 sample plots 100 m×100 m in size along a gradient of fixed distances from one herder's stationary site and then surveyed all the woody plants in these plots. A spatial point pattern analysis was employed to clarify the spatial distribution and interaction of these woody plants. The results indicated that old U. pumila trees (DBH ? 20 cm) showed a random distribution and that medium U. pumila trees (5 cm ? DBH < 20 cm) showed an aggregated distribution at a smaller scale and a random distribution at a larger scale; few or no juvenile trees (DBH < 5 cm) were present, and seedlings (without DBH) formed aggregations in all 3 plots. These findings can be explained by an alternate seasonal grazing-mowing regime (exclosure in summer, mowing in autumn and grazing in winter and spring); the shrubs in all 3 plots exist along a grazing gradient that harbors xerophytic and mesophytic shrubs. Of these shrubs, xerophytic shrubs show significant aggregation at a smaller scale (0-5.5 m), whereas mesophytic shrubs show significant aggregation at a larger scale (0-25 m), which may be the result of the dual effects of grazing pressure and climate change. Medium trees and seedlings significantly facilitate the distributions of xerophytic shrubs and compete significantly with mesophytic shrubs due to differences in water use strategies. We conclude that the implementation of an alternative grazing-mowing regime results in xerophytic shrub encroachment or existence, breaking the chain of normal succession in a U. pumila tree community in this typical temperate savanna ecosystem. This might eventually result in the degradation of the original tree-dominated savanna to a xerophytic shrub-dominated savanna.

SUBMITTER: Wang X

PROVIDER: S-EPMC4510874 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Spatial Pattern and Interactions of Woody Plants on the Temperate Savanna of Inner Mongolia, China: The Effects of Alternating Seasonal Grazing-Mowing Regimes.

Wang Xiao X Zhang Bo B Zhang Kebin K Zhou Jinxing J Ahmad Bilal B

PloS one 20150721 7

Ulmus pumila tree-dominated temperate savanna, which is distributed widely throughout the forest-steppe ecotone on the Mongolian Plateau, is a relatively stable woody-herbaceous complex ecosystem in northern China. Relatively more attention has been paid to the degradation of typical steppe areas, whereas less focus has been placed on the succession of this typical temperate savanna under the present management regime. In this study, we established 3 sample plots 100 m×100 m in size along a grad ...[more]

PMID: 26196956

Similar Datasets

Project description:Enclosure and grazing can significantly change the turnover of nitrogen in grassland soil. Changes of soil nitrogen mineralization and ammonium-oxidizing microorganisms caused by enclosure in different grazing intensities (about 30 years of grazing history) grassland, however, has rarely been reported. We selected the grassland sites with high and medium grazing intensity (HG and MG, 4 and 2 sheep ha-1, respectively) and had them enclosed (45 × 55 m) in 2005 while outside the enclosure was continuously grazed year-round. A two factorial study was designed: grazing intensity (MG and HG sites) and enclosure (fence and non-fence). Nitrogen mineralization was detected through a laboratory incubation experiment. The abundance and community structure of soil ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were analyzed using quantitative PCR (q-PCR), terminal-restriction fragment length polymorphism (T-RFLP), cloning, and sequencing. Results showed that compared with MG site, at HG site the AOB abundance and community structure of AOB changed significantly while the AOA abundance and community structure did not change obviously. Enclosure significantly decreased the cumulative mineralized N, N mineralization rate, the abundance of AOB and the AOB community structure at the HG site, while at MG site, enclosure did not change these parameters. Potential nitrification rate (PNR) was positively correlated with the abundance of AOA and AOB at the MG and HG sites, respectively. The abundance of AOA was significantly correlated with soil pH; however, AOB abundance was significantly correlated with soil available N, total N, C/N ratio, pH, etc. The phylogenetic analysis showed that Nitrososphaeraceae and Nitrosomonadaceae were the dominant AOA and AOB, respectively. Totally, the responses of AOB and AOA mainly were associated to changes in soil physicochemical properties caused by different intensity grazing; AOB and AOA may be the dominant functional players in ammonia oxidation processes at HG and MG site, respectively.

Dataset Information

The Spatial Pattern and Interactions of Woody Plants on the Temperate Savanna of Inner Mongolia, China: The Effects of Alternating Seasonal Grazing-Mowing Regimes.

Publications

The Spatial Pattern and Interactions of Woody Plants on the Temperate Savanna of Inner Mongolia, China: The Effects of Alternating Seasonal Grazing-Mowing Regimes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets