scholarly journals How Large-Scale Anthropogenic Activities Influence Vegetation Cover Change in China? A Review

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 320
Author(s):  
Dingrao Feng ◽  
Meichen Fu ◽  
Yiyu Sun ◽  
Wenkai Bao ◽  
Min Zhang ◽  
...  

Vegetation cover plays a key role in terrestrial ecosystem; therefore, it is important for researchers to investigate the variation and influencing factors of vegetation cover. China has experienced a large-scale vegetation cover change in recent years. We summarized the literature of vegetation cover change and revealed how large-scale anthropogenic activities influence vegetation cover change in China. Afforestation and intensification of cropland played a key role in large-scale greening. Urbanization showed a “U” shape to influence vegetation cover change. Mining and reclamation, land abandonment and land consolidation, and regional natural protection all had a unique influence on the change of vegetation cover. Indeed, the large-scale vegetation cover change was caused by interaction of anthropogenic factors and part human-driven climate change. Anthropogenic factors influenced climate change to indirectly alter the condition of plant growth. Interaction between climate change and human activities influence on vegetation cover still needs to be further investigated in the future.

2021 ◽  
Author(s):  
Lena Reifschneider ◽  
Vinzenz Franz Eichinger ◽  
Evelin Pihlap ◽  
Noelia Garcia-Franco ◽  
Anna Kühnel ◽  
...  

<p>The application of rock powder is an option to improve soil fertility while valorising the overburden material produced by industries. The “enhanced weathering” of silicate rock has also gained recent interest in the scientific community for its potential to mitigate climate change. However, the effect of rock powder on the soil physical properties remains unclear, especially under climate change (e.g., increasing drought events). Prior to any large scale application of rock powder, it is crucial to disentangle the potential effects of rock powder application on its environment. In a mesocosm experiment, we explored the effect of three rock powders on plant biomass, soil aggregation and organic carbon (OC) allocation within aggregates, in two soils with clayey and sandy textures, under regular watering or severe drought conditions. We demonstrate that the rock powder was the third factor after drought and soil texture significantly affecting the plant growth, resulting in a significant plant biomass decrease ranging from - 13 % to - 42 % compared with the control. We mainly attribute this effect to the increase of the already neutral soil pH, along with the release of excessive heavy metal amounts at a toxic range for the plant. Yet, we found that adding rock powder to the soil resulted in an increase of the relative amount of microaggregates in the soil by up to + 70 %, along with a re-distribution of OC within the fine fractions of the soil (up to + 32 % of OC in < 250 µm fractions). The new mineral-mineral and organo-mineral interactions promoted by the rock powder addition could potentially favour OC persistence in soil on the long term. With our results, we insist on the potential risks for plant growth associated to the application of rock powder when not handled properly. In addition to the current enthusiasm around the capacity of rock powder to enhance carbon sequestration in the inorganic form, we also encourage scientists to focus their research on its effect on soil structure properties and OC storage.</p>


2020 ◽  
Vol 12 (7) ◽  
pp. 1113
Author(s):  
Shahid Naeem ◽  
Yongqiang Zhang ◽  
Jing Tian ◽  
Faisal Mueen Qamer ◽  
Aamir Latif ◽  
...  

Accurate assessment of vegetation dynamics provides important information for ecosystem management. Anthropogenic activities and climate variations are the major factors that primarily influence vegetation ecosystems. This study investigates the spatiotemporal impacts of climate factors and human activities on vegetation productivity changes in China from 1985 to 2015. Actual net primary productivity (ANPP) is used to reflect vegetation dynamics quantitatively. Climate-induced potential net primary productivity (PNPP) is used as an indicator of climate change, whereas the difference between PNPP and ANPP is considered as an indicator of human activities (HNPP). Overall, 91% of the total vegetation cover area shows declining trends for net primary productivity (NPP), while only 9% shows increasing trends before 2000 (base period). However, after 2000 (restoration period), 78.7% of the total vegetation cover area shows increasing trends, whereas 21.3% of the area shows decreasing trends. Moreover, during the base period, the quantitative contribution of climate change to NPP restoration is 0.21 grams carbon per meter square per year (gC m−2 yr−1) and to degradation is 2.41 gC m−2 yr−1, while during the restoration period, climate change contributes 0.56 and 0.29 gC m−2 yr−1 to NPP restoration and degradation, respectively. Human activities contribute 0.36 and 0.72 gC m−2 yr−1 during the base period, and 0.63 and 0.31 gC m−2 yr−1 during the restoration period to NPP restoration and degradation, respectively. The combined effects of climate and human activities restore 0.65 and 1.11 gC m−2 yr−1, and degrade 2.01 and 0.67 gC m−2 yr−1 during the base and restoration periods, respectively. Climate factors affect vegetation cover more than human activities, while precipitation is found to be more sensitive to NPP change than temperature. Unlike the base period, NPP per unit area increases with an increase in the human footprint pressure during the restoration period. Grassland has more variability than other vegetation classes, and the grassland changes are mainly observed in Tibet, Xinjiang, and Inner Mongolia regions. The results may help policy-makers by providing necessary guidelines for the management of forest, grassland, and agricultural activities.


2020 ◽  
Author(s):  
Yanwen Wang

Net primary productivity (NPP) is an essential indicator of ecosystem function and sustainability and plays a vital role in the carbon cycle, especially in arid and semi-arid grassland ecosystems. Quantifying trends in NPP and identifying the contributing factors are important for understanding the relative impacts of climate change and human activities on grassland degradation. We quantified spatial and temporal patterns in potential NPP (NPPP) and actual NPP (NPPA) in Kyrgyzstan from 2000 to 2014 based on the Zhou Guangsheng model and MOD17A3 NPP data, respectively. By calculating the difference between NPPP and NPPA, we inferred human-induced NPP (NPPH) and thereby characterised changes in grassland NPP attributable to anthropogenic activities. We found that over the past two decades, both climatic variation and anthropogenic activities have significantly affected Kyrgyzstan’s grasslands. Grassland NPP decreased overall but patterns varied between provinces. Climate change, in particular changes in precipitation was the dominant factor driving grassland degradation in the north but human pressures also contributed. In the south however, human activities were associated with extensive areas of grassland recovery. The results provide important contextual understanding for supporting policy for grassland maintenance and restoration under climate change and intensifying human pressures.


2018 ◽  
Vol 53 ◽  
pp. 03060
Author(s):  
Xinrui Luo ◽  
Wunian Yang ◽  
Liang Liu ◽  
Yuhang Zhang

The hilly area of central Sichuan is one of the ecologically fragile regions in the upper reaches of the Yangtze River, and it is also the main part of ecological engineering construction. The ecological environment in the study area is related to the ecological security in the middle and lower reaches of the Yangtze River. Recent years have witnessed a great change in vegetation cover in this area as a result of climate change. Therefore, it is necessary to identify the changing patterns of vegetation cover and the impacts of climate change on the vegetation cover change in the study area. In this paper, the characteristics of vegetation cover change over the past 15 years were analyzed, based on the dataset of MODIS NDVI from 2001 to 2015 as well as the climate data from 55 meteorological stations, with methods such as maximum value composite (MVC), linear regression and correlation coefficient. The results showed that the annual maximum average NDVI in the hilly areas of central Sichuan has increased at a rate of 5.84/10a (P<0.01), while the summer average NDVI has increased at a rate of 1.6/10a (P>0.1). The spatial distribution of annual NDVI significantly increased (31.58%) was greater than the significantly decreasing trend (2.90%). Besides, areas with significantly positive correlation and significantly negative correlation between NDVI and precipitation in summer accounted for 16.91% and 2.5% of the total area, respectively. And, the correlation between NDVI and precipitation in summer was different in different regions.


2019 ◽  
pp. 39-56 ◽  
Author(s):  
E. A. Volkova ◽  
V. N. Khramtsov

The article is devoted to the vegetation mapping of the “Levashovskiy les”— a large forest-mire massif located in the northern part of St. Petersburg (Fig. 1). It continues a series of articles on the vegetation of existing and proposed specially protected natural areas of St. Petersburg (Volkova, Khramtsov, 2018). Large-scale map of modern vegetation (Fig. 2) is presented; the map legend includes 67 main numbers, the signs and numeric indexes at the numbers made it possible to show 93 mapping units (associations and their variants). Brief description of the main types of plant communities (spruce, pine, birch, aspen, gray alder and black alder forests; raised bogs, transitional mires and fens, floodplain and upland meadows) reveals the content of the legend. Vegetation cover is characterized by the dominance of secondary communities. The main anthropogenic impacts on modern vegetation are following: drainage reclamation, deforestation and former agricultural use, forest fires, gas pipelines, highways. Most of the forest communities are secondary ones; they have grown under the pressure of various anthropogenic factors and at different time. Nowadays an active process of natural regeneration of conife­rous (mainly spruce) trees goes in the forests. Plant community structure and species composition were taken into account as well as their dynamic state. To assess the degree of disturbance of plant communities and the potential for their restoration, the analysis of all mapped vegetation categories with respect to their position in the ranks of restorative successions was made. Then an assessment map “Dynamic state of plant communities” (Fig. 3) was compiled. The map shows following categories of dynamic types of communities: conventionally primary; relatively long-term secondary and stable long-term secondary (Sukachev, 1938; Isachenko, 1964; Karpenko, 1965; Gribova, Isachenko, 1972); short-term secondary that were divided into 3 categories representing different stages of restorative series. Present state of the vegetation cover of the “Levashovskiy les” can be determined by the ratio of the areas of conventionally primary and secondary communities. Areal analysis of dynamic categories of plant communities showed that only a bit more than 20 % of the territory is occupied by conventionally primary communities and about 60 % – by short-term secondary ones with good restorative potential. Without strong anthropogenic and natural disturbances, a significant part of the disturbed plant communities will be able to self-restore to their natural state. The establishment of a specially protected natural area as well as the regulation of conservation regime will support restoration process of nature ecosystems.


2015 ◽  
Vol 113 (3) ◽  
pp. 793-797 ◽  
Author(s):  
Naomi M. Levine ◽  
Ke Zhang ◽  
Marcos Longo ◽  
Alessandro Baccini ◽  
Oliver L. Phillips ◽  
...  

Amazon forests, which store ∼50% of tropical forest carbon and play a vital role in global water, energy, and carbon cycling, are predicted to experience both longer and more intense dry seasons by the end of the 21st century. However, the climate sensitivity of this ecosystem remains uncertain: several studies have predicted large-scale die-back of the Amazon, whereas several more recent studies predict that the biome will remain largely intact. Combining remote-sensing and ground-based observations with a size- and age-structured terrestrial ecosystem model, we explore the sensitivity and ecological resilience of these forests to changes in climate. We demonstrate that water stress operating at the scale of individual plants, combined with spatial variation in soil texture, explains observed patterns of variation in ecosystem biomass, composition, and dynamics across the region, and strongly influences the ecosystem’s resilience to changes in dry season length. Specifically, our analysis suggests that in contrast to existing predictions of either stability or catastrophic biomass loss, the Amazon forest’s response to a drying regional climate is likely to be an immediate, graded, heterogeneous transition from high-biomass moist forests to transitional dry forests and woody savannah-like states. Fire, logging, and other anthropogenic disturbances may, however, exacerbate these climate change-induced ecosystem transitions.


2018 ◽  
Vol 15 (18) ◽  
pp. 5677-5698 ◽  
Author(s):  
Johannes Meyerholt ◽  
Sönke Zaehle

Abstract. The availability of nitrogen is one of the primary controls on plant growth. Terrestrial ecosystem nitrogen availability is not only determined by inputs from fixation, deposition, or weathering, but is also regulated by the rates with which nitrogen is lost through various pathways. Estimates of large-scale nitrogen loss rates have been associated with considerable uncertainty, as process rates and controlling factors of the different loss pathways have been difficult to characterize in the field. Therefore, the nitrogen loss representations in terrestrial biosphere models vary substantially, adding to nitrogen cycle-related uncertainty and resulting in varying predictions of how the biospheric carbon sink will evolve under future scenarios of elevated atmospheric CO2. Here, we test three commonly applied approaches to represent ecosystem-level nitrogen loss in a common carbon–nitrogen terrestrial biosphere model with respect to their impact on projections of the effect of elevated CO2. We find that despite differences in predicted responses of nitrogen loss rates to elevated CO2 and climate forcing, the variety of nitrogen loss representation between models only leads to small variety in carbon sink predictions. The nitrogen loss responses are particularly uncertain in the boreal and tropical regions, where plant growth is strongly nitrogen-limited or nitrogen turnover rates are usually high, respectively. This highlights the need for better representation of nitrogen loss fluxes through global measurements to inform models.


Sign in / Sign up

Export Citation Format

Share Document