scholarly journals Dynamics of Grassland Vegetation Composition across different Land-use Types on the Qinghai Tibet Plateau: Implications to Combat Grassland Degradation

2021 ◽  
Vol 04 (04) ◽  
pp. 95-114
Author(s):  
Moses Fayiah ◽  
◽  
ShiKui Dong ◽  
Roberto Xavier Supe Tulcan ◽  
Sanjay Singh ◽  
...  
Keyword(s):  
Land Use ◽  
Mitigation Measures ◽  
Tibet Plateau ◽  
Grassland Degradation ◽  
Land Uses ◽  
Vegetation Composition ◽  
Grassland Vegetation ◽  
Land Use Types ◽  
Evenness Indices ◽  
Qinghai Tibet Plateau

The constant biotic and abiotic interventions on the Qinghai Tibet Plateau (QTP) are seriously degrading the grasslands and, at the same time, restricting the active ecosystem function and grassland vegetation distribution on the plateau. This research analyses the dynamics of grassland vegetation composition across three land uses and counties. The degree of grassland degradation was divided into four land-use types based, i.e., healthy grassland (HG), restored grassland (RG), moderately degraded (MD) grassland, and severely degraded (SD) grassland. About 32 plant species were recorded in Tiebujia county, 28 in Maqin county, and 18 in Maduo county. Results showed Poa crymophila, Polygonum sibiricum, Leontopodium nanum and Oxytropis falcatabunge as the most abundant grassland species in all land-uses and counties. The richness of species ranged from 8 to 12 species per land-use, suggesting low richness and diversity in restored and degraded grassland. A positive non-significantly mean change (p<0.05) was detected for richness and evenness indices while a negative mean change (p<0.05) was detected for Simpson and Shannon indices in the alpine meadow and steppe in both Maqin and Maduo county. The results imply that degradation affects grassland vegetation, health, and distribution across the QTP. Plant total cover for the healthy grassland covered far more areas than other land-uses. Urgent mitigation measures to halt grassland degradation and decline in plant vegetation composition on the plateau should be adopted.

scholarly journals LAND USE/LAND COVER CHANGE AND ENVIRONMENTAL EFFECTS IN THE NORTHEASTERN QINGHAI-TIBET PLATEAU FROM 1980 TO 2015

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 945-952
Author(s):  
J. Y. Zhao ◽  
Q. Song ◽  
M. Du ◽  
G. R. Li ◽  
J. Yang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Tibet Plateau ◽  
Grassland Degradation ◽  
Land Use Land Cover ◽  
Change Rate ◽  
Unused Land ◽  
Relative Change ◽  
Qinghai Tibet Plateau

Abstract. The Qinghai-Tibet Plateau ecosystem is sensitive and fragile, the grassland degradation and soil erosion in the plateau are still increasing. In this paper, we conducted a quantitative study to clarify the characteristics of land use/land cover change, the driving factors, and the environmental effects in the plateau. We focused on the northeastern Qinghai-Tibet Plateau as an example, and created land use change matrices and determined the relative change rate, vegetation cover, and environmental quality index using land use data and NDVI3g data from 1980 to 2015. The results show that there were significant differences in land use/land cover change in the study area around 2000, while the farmland did not increase significantly, and the water areas exhibited a decreasing trend initially followed by an increasing trend, the unused land first increased and then decreased, and residential areas increased significantly after 2000. The relative change rate of the grassland was the largest between 1980 and 2015, while most of the grassland was converted into farmland, residential land, and unused land. In addition, grassland degradation increased significantly. Considerable spatial heterogeneity in vegetation and land use/land cover was observed in the study area. The vegetation cover decreased in some areas due to the grassland degradation, however, the others areas showed improvements due to the influences of policies and climate change. The environmental index and ecological service value of the study area declined and the environment deteriorated during the study period.

scholarly journals Evaluation Of Selected Soil Structural Properties of Different Land Uses In Oforola, Imo State, Nigeria

2019 ◽  
pp. 35-42
Keyword(s):  
Land Use ◽  
Structural Properties ◽  
Oil Palm ◽  
Secondary Forest ◽  
Land Uses ◽  
Grassland Vegetation ◽  
Water Stable Aggregates ◽  
Oil Palm Plantation ◽  
Land Use Types ◽  
Bush Fallow

This study centered on evaluating selected soil structural properties of different land uses in Oforola, Imo State, Nigeria. Soil samples were collected from six different land-use types, namely, secondary forest, bush fallow, bare plot, cassa- va cultivated plot, oil palm plantation, and grassland vegetation. Soil auger was used to collect soil samples from each of the land use types at two (2) depths (0 – 15 cm and 15 – 30cm). The samples from each land use at different depths were composited, mixed thoroughly and sub-sample, and analyzed in the laboratory for selected physical and chemical parameters. The data were analyzed statisti- cally using GENSTAT software Ver. 8.2 in Completely Randomized Design (CRD). The soils of the study area were principally sandy, with sand accounting for more than 65% of the inorganic mineral fragment in the soil at 0 – 15 cm depth and 15 – 30 cm depth. Land use effect on the dispersion ratio (DR) was significant (P ≤ 0.05) at the 0 -15 cm and 15 – 30 cm depth. However, oil palm plantation recorded significantly (P ≤ 0.05) higher dispersion ratio at the 0 – 15 cm depth. Bulk density was highest (1.57 g/cm3) in grassland vegetation and lowest in secondary forest and bush fallow (1.25 g/cm3). The bulk density val- ues for bare plot, cassava cultivated plot and oil palm plantation were 1.51 g/ cm3, 1.35 g/cm3, and 1.29 g/cm3, respectively. The total porosity of the soil was significantly higher in secondary forest (51.84%). Total porosity values for bush fallow, Cassava cultivated plot, oil palm plantation, bare plot, and grassland veg- etation were 51.83%, 48.38%, 50.97%, 42.36%, and 40.08%, respectively. The proportion of water stable aggregates were significantly (P ≤ 0.05) influenced by the various land-use types. On the average, secondary forest and bush fallow had higher water-stable aggregates of various sizes compared to the cassava cultivat- ed plot that had moderate water-stable aggregates. The least water-stable aggre- gates of various sizes were recorded in grassland vegetation and oil palm planta- tion. The mean weight diameters were significantly (P ≤ 0.05) influenced by var- ious land-use types. Low mean weight diameter was observed for oil palm plan- tation, grassland vegetation and cassava cultivated plots. Based on the findings of the study, secondary forest and bush fallow land-use types possessed the most stable structural properties and also showed optimal impact compared to other land uses in Oforola soils, Imo State, Nigeria

scholarly journals Land Use-Driven Changes in Ecosystem Service Values and Simulation of Future Scenarios: A Case Study of the Qinghai–Tibet Plateau

2021 ◽  
Vol 13 (7) ◽  
pp. 4079
Author(s):  
Yongkang Zhou ◽  
Xiaoyao Zhang ◽  
Hu Yu ◽  
Qingqing Liu ◽  
Linlin Xu
Keyword(s):  
Land Use ◽  
Global Climate Change ◽  
Global Climate ◽  
Land Use Changes ◽  
Tibet Plateau ◽  
Natural Development ◽  
Ecological Protection ◽  
Land Use Types ◽  
Bare Land ◽  
Qinghai Tibet Plateau

Global climate change and land use change arising from human activities affect the ecosystem service values (ESVs). Such impacts have increasingly become significant, especially in the Qinghai–Tibet Plateau (QTP). Major factors impeding the construction of China’s “ecological security barrier” are shifts in land-use patterns under rapid urbanization, irrational crop and animal husbandry activities, and tourism. In the present study, land use changes in the QTP in recent years were analyzed to determine their impacts on ESVs, followed by simulations of the interactive and evolutionary relationships between land use and ESVs under two scenarios: natural development scenarios and ecological protection scenarios. According to the results, the QTP land-use structure has a small change, and the main land use type is alpine grassland, followed by bare land and woodland. The stability of the major land use types is the key factor responsible for the overall increasing ESV trend. Different regions on the QTP had substantially varied ESVs. The northwest and southeast regions are mostly bare land, which is a concentrated area of low value of ecosystem services. A variety of land use types including grassland and woodland have been found in the humid and semi-humid areas of the central region, so the high value of ecosystem services is concentrated in this area to form a hot spot, with a Z value of 0.63–2.84. Simulations under the natural development and ecological protection scenarios revealed that land use changes guided by ecological policies were more balanced and the associated ESVs were relatively higher than those under the natural development scenario. Under a global climate change context, human activities on the QTP should be better managed. Sustainable development in the region could be facilitated by ensuring synchronization between resource availability and adopted socioeconomic activities.

scholarly journals A comprehensive, locally adapted soil quality indexing under different land uses in a typical watershed of the eastern Qinghai-Tibet Plateau

2021 ◽  
Vol 125 ◽  
pp. 107445
Author(s):  
Xiaohong Zhao ◽  
Miaomiao Tong ◽  
Yuejun He ◽  
Xiuru Han ◽  
Lingqing Wang
Keyword(s):  
Soil Quality ◽  
Tibet Plateau ◽  
Land Uses ◽  
Qinghai Tibet Plateau

scholarly journals Soil gross nitrogen transformations in forestland and cropland of Regosols

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Ren ◽  
Jinbo Zhang ◽  
Hamidou Bah ◽  
Christoph Müller ◽  
Zucong Cai ◽  
...  
Keyword(s):  
Land Use ◽  
Southwest China ◽  
Nitrification Rate ◽  
Land Uses ◽  
Nitrogen Transformations ◽  
N Losses ◽  
Retention Capacity ◽  
N Transformations ◽  
Autotrophic Nitrification ◽  
Land Use Types

AbstractSoil gross nitrogen (N) transformations could be influenced by land use change, however, the differences in inherent N transformations between different land use soils are still not well understood under subtropical conditions. In this study, an 15N tracing experiment was applied to determine the influence of land uses on gross N transformations in Regosols, widely distributed soils in Southwest China. Soil samples were taken from the dominant land use types of forestland and cropland. In the cropland soils, the gross autotrophic nitrification rates (mean 14.54 ± 1.66 mg N kg−1 day−1) were significantly higher, while the gross NH4+ immobilization rates (mean 0.34 ± 0.10 mg N kg−1 day−1) were significantly lower than those in the forestland soils (mean 1.99 ± 0.56 and 6.67 ± 0.74 mg N kg−1 day−1, respectively). The gross NO3− immobilization and dissimilatory NO3− reduction to NH4+ (DNRA) rates were not significantly different between the forestland and cropland soils. In comparison to the forestland soils (mean 0.51 ± 0.24), the cropland soils had significantly lower NO3− retention capacities (mean 0.01 ± 0.01), indicating that the potential N losses in the cropland soils were higher. The correlation analysis demonstrated that soil gross autotrophic nitrification rate was negatively and gross NH4+ immobilization rate was positively related to the SOC content and C/N ratio. Therefore, effective measures should be taken to increase soil SOC content and C/N ratio to enhance soil N immobilization ability and NO3− retention capacity and thus reduce NO3− losses from the Regosols.

scholarly journals High land-use intensity exacerbates shifts in grassland vegetation composition after severe experimental drought

2018 ◽  
Vol 24 (5) ◽  
pp. 2021-2034 ◽  
Author(s):  
Andreas Stampfli ◽  
Juliette M. G. Bloor ◽  
Markus Fischer ◽  
Michaela Zeiter
Keyword(s):  
Land Use ◽  
Land Use Intensity ◽  
Vegetation Composition ◽  
Grassland Vegetation

Response of phosphorus fractions to land-use change followed by long-term fertilization in a sub-alpine humid soil of Qinghai–Tibet plateau

2018 ◽  
Vol 19 (3) ◽  
pp. 1109-1119 ◽  
Author(s):  
Xiaolei Sun ◽  
Meng Li ◽  
Guoxi Wang ◽  
Marios Drosos ◽  
Fulai Liu ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Phosphorus Fractions ◽  
Tibet Plateau ◽  
Qinghai Tibet Plateau

scholarly journals The environment they lived in: anthropogenic changes in local and regional vegetation composition in eastern Fennoscandia during the Neolithic

2020 ◽  
Author(s):  
Teija Alenius ◽  
Laurent Marquer ◽  
Chiara Molinari ◽  
Maija Heikkilä ◽  
Antti Ojala
Keyword(s):  
Land Use ◽  
Sediment Cores ◽  
Regional Scale ◽  
Reconstruction Algorithm ◽  
Land Uses ◽  
Neolithic Period ◽  
Vegetation Composition ◽  
Fire Dynamics ◽  
Disturbance Processes ◽  
The Impact

Abstract Understanding about regional versus local changes in vegetation is critical in answering archaeological questions, in particular at a time when humans are assumed to have caused higher disturbances at local scales rather than regional scales; this is the case during the Neolithic. The aim of this paper is to assess the impact of Neolithic land use on regional and local vegetation dynamics, plant composition and disturbance processes (e.g. fire) in eastern Fennoscandia. We apply the Landscape Reconstruction Algorithm (LRA) to high-resolution pollen records from three lacustrine sediment cores that cover the Neolithic period. We calculate changes in vegetation composition and the rate of plant compositional change. Fire dynamics are estimated as an indicator of land use, although fire can result from both natural and anthropogenic disturbances. Our results show that during the Early Neolithic, changes were mainly driven by natural and climate-induced factors and vegetation composition and fire activity were similar at both regional and local scales. From ca. 4000 bc onwards, trends in vegetation and fire dynamics start to differ between regional and local scales. This is due to local land uses that are overshadowed at the regional scale by climate-induced factors. The use of the LOVE model in pollen analyses is therefore very useful to highlight local land uses that are not visible by using REVEALS.

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