Spatial conservation prioritization considering socioeconomic costs and degradation conditions in the Southwest China Biodiversity Hotspot

2021 ◽  
pp. 1-8
Author(s):  
Wei Fu ◽  
Qi Ding ◽  
Zhe Sun ◽  
Tao Xu
Keyword(s):  
Southwest China ◽  
Habitat Degradation ◽  
Ecological Integrity ◽  
Biodiversity Loss ◽  
Biodiversity Hotspot ◽  
Karst Area ◽  
Network Coverage ◽  
Target Species ◽  
Key Species ◽  
Spatial Conservation Prioritization

Summary There have been calls for the expansion of protected areas (PAs) to tackle the ongoing biodiversity loss, yet it is unclear where future PAs might help to protect biodiversity in degraded landscapes under the conservation planning principles of complementarity, connectivity and cost-effectiveness. Our conservation goal is to increase the PA network coverage to up to 30% of the landscape of the Zhangjiang River Basin for target species in the karst area of southwest China, a global biodiversity hotspot. Zonation 4GUI was used to evaluate the adequacy of current PAs and to strategically expand PAs while maximizing the coverage of target species and considering ecological integrity and socioeconomic activities. The results show that significant habitat degradation has occurred across 77.9% of the basin. The current PAs cover 6.3% of the site and represent 8.7% of the total distribution of key species. With regards to the threshold of protection of 30% of the area, protecting an additional 27.2% of the site under an ecological integrity prioritization scenario and a scenario of the socioeconomic costs involved in iteration would cover 93.5% and 80.4% of the ranges of the key species, respectively. Our results can be used to inform the upcoming actions associated with karst area conservation-related policies.

scholarly journals Twenty-Three Years of Land-Use Changes Induced Considerable Threats to the Main Wetlands of Sardinia and Sicily (Italy) along the Mediterranean Bird Flyways

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 240
Author(s):  
Alessandro Ferrarini ◽  
Marco Gustin ◽  
Claudio Celada
Keyword(s):  
Land Use ◽  
Habitat Degradation ◽  
Land Use Changes ◽  
Biodiversity Loss ◽  
Natura 2000 ◽  
Global Level ◽  
Natura 2000 Network ◽  
Stopover Sites ◽  
The Mediterranean ◽  
Agricultural Areas

Biodiversity loss has multiple causes, but habitat degradation through land-use change is the predominant driver. We investigated the effectiveness of the Natura 2000 network in preserving the main wetlands of the two largest islands of the Mediterranean region, whose conservation is critical for many avian species at European and global level, in a 23-year period (1990–2012). In Sardinia, the surroundings of 22 wetlands were affected by an increase in artificial areas (+64 ha/year) and decrease in agricultural (−54 ha/year) and natural (−17 ha/year) ones. In Sicily, the surroundings of 16 wetlands were impacted by an increase in agricultural areas (+50 ha/year) and decrease in natural and semi-natural ones (−62 ha/year). Results show that the Natura 2000 policies were effective in preserving wetlands (no shrinkages detected in both regions), but their surroundings experienced intense processes of degradation and artificialization in all the sub-periods considered (1990–2000, 2000–2006, 2006–2012), whose effects are now threatening waterbirds and wetland integrity. The enlargement of the existing Natura 2000 sites, the creation of new ones and the speedup of the application of the rules of the Habitats and Birds Directives seem necessary to counteract the rapid land-use changes around these important stopover sites.

scholarly journals Reforestation Impacted Soil Heavy Metal Fractionation and Related Risk Assessment in the Karst Area, Southwest China

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 891
Author(s):  
Qian Zhang ◽  
Guilin Han ◽  
Xingliang Xu
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Ecological Risk ◽  
Southwest China ◽  
Risk Index ◽  
Contamination Factor ◽  
Karst Area ◽  
Risk Assessment Code ◽  
Bcr Sequential Extraction ◽  
Soil Heavy Metals

Human agricultural activities have resulted in widespread land degradation and soil contamination in the karst areas. However, the effects of reforestation after agricultural abandonment on the mobility risks and contamination of heavy metals have been rarely reported. In the present study, six soil profiles were selected from cropland and abandoned cropland with reforestation in the Puding karst regions of Southwest China. The Community Bureau of Reference (BCR) sequential extraction method was used to evaluate the compositions of different chemical fractions of soil heavy metals, including Fe, Mn, Cr, Zn, Ni, and Cd. The total contents of Cr, Ni, Zn, Cd, and Mn in the croplands were significantly higher than those in the abandoned croplands. For all soils, Cr, Ni, Zn, and Fe were mainly concentrated in the residual fractions (>85%), whereas Mn and Cd were mostly observed in the non-residual fractions (>65%). The non-residual fractions of Cd, Cr, Ni, and Zn in the croplands were higher than those in the abandoned croplands. These results indicated that the content and mobility of soil heavy metals decreased after reforestation. The individual contamination factor (ICF) and risk assessment code (RAC) showed that Cd contributed to considerable contamination of karst soils. The global contamination factor (GCF) and potential ecological risk index (RI) suggested low contamination and ecological risk of the investigated heavy metals in the croplands, moreover they can be further reduced after reforestation.

scholarly journals Impact of different fertilizers on the carbonate weathering in a typical karst area, Southwest China: a field column experiment

2016 ◽  
Author(s):  
Chao Song ◽  
Changli Liu ◽  
Guilin Han
Keyword(s):  
Southwest China ◽  
Column Experiment ◽  
Phosphate Fertilizer ◽  
Global Scale ◽  
Karst Area ◽  
Carbonate Weathering ◽  
Nitrogenous Fertilizer ◽  
Co2 Consumption ◽  
Common Ion ◽  
Calcium Magnesium

Abstract. Carbonate weathering, as a significant vector for the movement of carbon both between and within ecosystems, are strongly influenced by anthropogenic perturbations such as agricultural fertilization. Different fertilizer may exert a different impact on carbonate weathering, but their differences are not still well-known so far. In this study, a field column experiment was employed to explore the responses of carbonate weathering to different fertilizer addition. The eleven different treatments with three replicates including control, NH4NO3, NH4HCO3, NaNO3, NH4Cl, (NH4)2CO3, Ca3(PO4)2, (NH4)3PO4, fused calcium-magnesium phosphate fertilizer (Ca-Mg-P), Urea and K2CO3 were established in this column experiment, where limestone and dolostone tablets were buried at the bottom of each to determine the weathering amount and ratio of carbonate in soil. The result showed that the addition of urea, NH4NO3, NH4HCO3, NH4Cl and (NH4)2CO3 distinctly increased carbonate weathering, which was attributed to the nitrification of NH4+, and the addition of Ca3(PO4)2, Ca-Mg-P and K2CO3 induced carbonate precipitation due to common ion effect. Whereas the (NH4)3PO4 and NaNO3 addition did not impact significantly on carbonate weathering. The results of NaNO3 treatment seem to be raising a new question: the little impact of nitrate on carbonate weathering may result in the overestimation of impact of N-fertilizer on CO2 consumption by carbonate weathering at the regional/global scale if the effect of NO3 and NH4 are not distinguished. Moreover, in order to avoid misunderstanding more or less, the statement that nitrogenous fertilizer can aid carbonate weathering should be replaced by ammonium fertilizer.

scholarly journals Anthropogenic impacts on Late Holocene land-cover change and floristic biodiversity loss in tropical southeastern Asia

2021 ◽  
Vol 118 (40) ◽  
pp. e2022210118 ◽  
Author(s):  
Zhuo Zheng ◽  
Ting Ma ◽  
Patrick Roberts ◽  
Zhen Li ◽  
Yuanfu Yue ◽  
...  
Keyword(s):  
Late Holocene ◽  
Southern China ◽  
Anthropogenic Impacts ◽  
Biodiversity Loss ◽  
Freshwater Wetland ◽  
Social Changes ◽  
Rice Agriculture ◽  
Human Land Use ◽  
Key Species ◽  
The Face

Southern China and Southeast Asia witnessed some of their most significant economic and social changes relevant to human land use during the Late Holocene, including the intensification and spread of rice agriculture. Despite rice growth being associated with a number of earth systems impacts, how these changes transformed tropical vegetation in this region of immense endemic biodiversity remains poorly understood. Here, we compile a pollen dataset incorporating ∼150,000 identifications and 233 pollen taxa to examine past changes in floral biodiversity, together with a compilation of records of forest decline across the region using 14 pollen records spanning lowland to mountain sites. Our results demonstrate that the rise of intensive rice agriculture from approximately 2,000 y ago led not only to extensive deforestation but also to remarkable changes of vegetation composition and a reduction in arboreal diversity. Focusing specifically on the Tertiary relic tree species, the freshwater wetland conifer Glyptostrobus (Glyptostrobus pensilis), we demonstrate how key species that had survived changing environmental conditions across millions of years shrank in the face of paddy rice farming and human disturbance.

Tracer vertical movement and its affecting factors in karst soil profiles using the simulated leaching method

2021 ◽  
Author(s):  
Jianghu He ◽  
Keli Zhang ◽  
Zihao Cao ◽  
Qihua Ke
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Southwest China ◽  
Vertical Movement ◽  
Karst Area ◽  
Affecting Factors ◽  
Tracer Movement ◽  
Traditional Research ◽  
Movement Distance ◽  
Karst Geomorphology

<p>Soil erosion is a severe issue in Southwest China due to complex karst geomorphology and excessive farming activities. It is also difficult to observe and evaluate using traditional research methods. Fortunately, as a supplement to traditional methods, the <sup>137</sup>Cs tracing technique has strong potential to monitor and evaluate soil loss in karst regions. However, <sup>137</sup>Cs might move downward with tiny particles under adequate rainfall conditions. This is critical because it directly affects accuracy of using the <sup>137</sup>Cs conversion model to evaluate soil erosion. Thus, in our study, in order to explore whether tracers actually moved vertically and to evaluate the movement distance and the factors influencing the movement, magnetic powder (Fe<sub>3</sub>O<sub>4</sub>) and rare earth oxides (CeO<sub>2 </sub>and La<sub>2</sub>O<sub>3</sub>) were used as the substitute tracers under different conditions (rainfall and leaching area) of a simulated leaching experiment, which possess similar properties as <sup>137</sup>Cs and have no toxicity problems in humans and the environment. The results showed that tracers moved downward 6 cm when water was added to simulate 1-10-year rainfall conditions and 8 cm when water was added to simulate 15-20-year rainfall conditions. The movement distance of tracers increased slowly with increasing water input, and the concentration of the tracers that moved related indirectly to the leaching area. Tracer movement at the edge of the simulated profile was affected by tracer type and concentration since there was no transition layer between soil and plastic column. Our field observations in two karst watersheds showed that ignoring the vertical movement of tracer can cause the overestimation of soil loss amount by 6.90% and 22.22% respectively. This study proved that in the karst area of Southwest China with abundant rainfall, <sup>137</sup>Cs would move vertically, and the soil loss will be overestimated if the vertical movement distance of the tracer is ignored.</p>

Interpretation of regional-scale distribution of high Hg in soils of karst area in southwest China

2018 ◽  
Vol 19 (3) ◽  
pp. 289-298
Author(s):  
Lanshi Nie ◽  
Xuemin Liu ◽  
Xueqiu Wang ◽  
Hanliang Liu ◽  
Wei Wang
Keyword(s):  
Southwest China ◽  
Regional Scale ◽  
Karst Area

scholarly journals Annual Runoff is Highly Linked to Precipitation Extremes in Karst Catchments of Southwest China

2017 ◽  
Vol 18 (10) ◽  
pp. 2745-2759 ◽  
Author(s):  
Zhenwei Li ◽  
Xianli Xu ◽  
Chaohao Xu ◽  
Meixian Liu ◽  
Kelin Wang ◽  
...  
Keyword(s):  
Water Resources ◽  
Southwest China ◽  
Climatic Factors ◽  
Precipitation Amount ◽  
Heavy Precipitation ◽  
Annual Runoff ◽  
Climatic Variables ◽  
Precipitation Extremes ◽  
Karst Area ◽  
Least Squares Regression

Abstract Karst landforms cover 7%–12% of the Earth’s continental area and provide water resources for 25% of the global population. Climate, particularly frequent climate extremes, may greatly affect the annual runoff, especially in climate-sensitive regions such as a karst area of southwest China. Knowledge of the linkage between climate and runoff is urgently needed for smart water resources management. This study therefore selected five catchments that have different carbonized rock coverage (from 11% to 64%) to detect the dominant climatic variables driving changes in annual runoff for the period of 1957–2011 in southwest China. Because climatic variables are highly codependent, a partial least squares regression (PLSR) was used to elucidate the linkages between runoff and 17 climatic variables. Results indicated that the dominant climatic factors driving annual runoff are annual total precipitation, rainy days, heavy precipitation amount, heavy precipitation days, rainstorm amount, and rainstorm days. These six factors are generally used to represent extreme climatic events, and hence it may demonstrate that annual runoff is highly linked to precipitation extremes in this region. The PLSR approach presented in this study is beneficial and novel, as it enables the elimination of codependency among the variables and facilitates a more unbiased view of the contribution of the changes in climatic variables to the changes in runoff. As a practical and simple tool, the PLSR approach is thus recommended for application to a variety of other catchments.

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