Min River Research Articles

Effects of spatial expansion between Phragmites australis and Cyperus malaccensis on variations of arsenic and heavy metals in decomposing litters in a typical subtropical estuary (Min River), China

To investigate the effects of spatial expansion between native invasive species (Phragmites australis) and commom native species (Cyperus malaccensis) on variations of micro-elements (Pb, Cr, Cu, Zn, Ni, Cd and As) in decomposing litters in the Min River estuary, in situ filed decomposition experiment was conducted in P. australis (PA) community (before expansion, BE), C. malaccensis (CM) community (before expansion, BE) and P. australis-C. malaccensis (PA′-CM’) community (during expansion, DE) from February 2016 to February 2017 by space-for- time substitution method. Results showed that the decomposition of C. malaccensis were faster than those of P. australis whether at BE stage or at DE stage. The decomposition rate of PA’ increased by 24.40% compared to PA whereas the value of CM’ decreased by 15.67% compared with CM. The concentrations of Pb, Cu, Zn, Ni, Cd and As in decomposing litters of P. australis (PA and PA’) and C. malaccensis (CM and CM’) generally showed increasing tendency and the values in the former were significantly lower than those in the latter (p < 0.05). The physicochemical sorption onto recalcitrant organic fractions and the substrate quality (C/N and M/C ratios) of decomposing litters were two important factors affecting the differences in As/metals variations between species. The levels of Cr in decaying litters increased initially and decreased afterward, and the values in P. australis were significantly higher than those in C. malaccensis (p < 0.05). Whether at BE stage or at DE stage, stocks of As/metals in decomposing litters of P. australis (PA and PA’) were generally higher than those of C. malaccensis (CM and CM’). The lower stocks of As/metals in CM or CM’ might be more dependent on its lower mass remaining. Compared with PA at BE stage, the accumulation of As/metals in decomposing litters of PA’ at DE stage decreased greatly, which might be ascribed to the lower precipitation of metal sulfides in PA’. Stocks of Zn, Ni, Cd and Cr in CM’ and stocks of Cr in PA’ generally evidenced the export of metals from decomposing litter to environment, indicating that the potential exposure risk of Zn, Ni, Cd and Cr might be increased as CM was invading by PA. This study found that the spatial expansion between P. australis and C. malaccensis not only altered the stocks of As/metals in decomposing litters but also increased the exposure risk of Zn, Ni, Cd and Cr in ecotone. In future, as the ecological functions of ecotone was precisely evaluated during the expansion of the two plants in the Min River estuary, the alterations of litter decomposition rates and the exposure risks of Zn, Ni and Cd caused by CM’ should be emphasized.

Miocene sedimentary provenance and paleogeography of the Hengchun Peninsula, southern Taiwan: Implications for tectonic development of the Taiwan orogen

The pre-collisional sedimentary provenance of southern Taiwan not only can offer important information about the paleogeography of the region prior to the Taiwan orogeny, but may also provide significant constraint for understanding the origin of the Central Range of Taiwan and the history of the orogen. Although there have been previous studies on sedimentary provenance of the Hengchun Peninsula, the southernmost part of the Taiwan mountain belt, these studies appear to have limited sample coverage. Therefore, we performed detrital zircon U-Pb geochronology and hafnium isotopic analysis of samples covering all three Mid-Late Miocene stratigraphic units of the peninsula. Our results suggest that, whereas the Minjiang (Min River) and the Jiulongjiang (Jiulong River) in SE China are the primary sediment sources for the Shihmen and Lilungshan Formations, the Loshui Formation was likely deposited in a deep sea fan originated from a rifted continental fragment in the south. The developing accretionary prism and proto-Taiwan may have also provided sediments to the area. The proposed presence of a continental fragment that provided sediments in the Loshui Formation supports the hypothesis that the Taiwan orogen may have formed as a double collision that incorporated not only the Luzon Arc and the Eurasian continental margin, but also rifted continental blocks in between.

Optically stimulated luminescence ages of the Hengyu site and their implications for anthropogenic activities in the Fuzhou Basin, South China

ABSTRACTThe chronologies of few Neolithic sites in the lower reaches of the Min River of China have been well investigated for the middle to late Holocene. In this study, the Hengyu Neolithic site in Fujian Province, South China, which has significant archaeological remains, was dated using blue‐stimulated optically stimulated luminescence (OSL) and accelerator mass spectrometry radiocarbon (AMS14C) techniques. The results, comprising nine OSL and three AMS14C ages through the Neolithic sequence, provide new evidence towards understanding the relationship between environmental evolution and human activities in the middle to late Holocene in the Fuzhou Basin and coastal areas of South China. The ages of the site deposits vary from 6.83 to 1.67 ka and can be divided into two main phases: the Keqiutou–Tanshishan culture period and the Bronze culture period. In contrast, the persistent periods of ancient human activities at the Hengyu site seem to correspond to regional sea‐level changes and the East Asian winter monsoon as a secondary factor, which can affect human activities through sea‐level impacts. The warm and high sea level conditions provided a liveable environment for the ancient humans of Fujian and even South China. The ages of two building column bases are linked to the early stage of the Han dynasty, suggesting a potentially favourable habitation environment; that is, ancient humans occupied and settled this area for the long term within this time period, which is consistent with sea‐level changes and palynology records. Copyright © 2019 John Wiley &amp; Sons, Ltd.

Effects of Tidal Scenarios on the Methane Emission Dynamics in the Subtropical Tidal Marshes of the Min River Estuary in Southeast China.

In order to accurately estimate the effects of tidal scenarios on the CH4 emission from tidal wetlands, we examined the CH4 effluxes, dissolved CH4 concentrations, and environmental factors (including in situ pH, Eh and electrical conductivity, porewater SO42−, NO3−, and NH4+) during inundation and air-exposure periods in high- and low-tide seasons in the Min River Estuary in southeast China. By applying static and floating chambers, our results showed that the CH4 effluxes during the inundation periods were relatively constant and generally lower than those during the air-exposed periods in both seasons. When compared, the CH4 effluxes during the air-exposed periods were significantly higher in the high-tide season than those in the low-tide season. In contrast, CH4 effluxes during the inundation periods were significantly lower in the high-tide season than those in the low-tide season. During the inundation periods, dissolved CH4 concentrations were inversely proportional to in situ Eh. Under air-exposed conditions, CH4 effluxes were proportional to in situ pH in both seasons, while the dissolved CH4 concentrations were negatively correlated with the porewater SO42− concentrations in both seasons. Our results highlighted that CH4 effluxes were more dynamic between inundation and air-exposure periods compared to low- and high-tide seasons.

Differences in biomass and silica content in typical plant communities with ecotones in the Min River estuary of southeast China.

Silica (Si) is a basic nutrient requirement for many aquatic organisms and its biogeochemical cycle plays an important role in estuarine coastal ecosystems. However, little is known about the role Si plays during plant–plant interactive processes in the marsh ecosystems. Here, variations in biomass, biogenic silica (BSi) content, and available Si content of Cyperus malaccensis-dominated marshes, Phragmites australis-dominated marshes, and their ecotonal marshes were studied in the Shanyutan marsh in the Min River estuary, China. Results showed that C. malaccensis and P. australis biomass in ecotones was lower than those in typical communities by 46.4% and 46.3%, respectively. BSi content in aboveground organs of C. malaccensis and culms and roots of P. australis was lower in ecotones than in typical communities, whereas BSi content in other organs showed the opposite trend. Biomass allocation in C. malaccensis and P. australis roots in ecotones was higher by 56.9% and 19.5%, respectively, and BSi stock in C. malaccensis and P. australis roots was higher than that in typical communities by 120.9% and 18.9%, respectively. Available Si content in ecotonal marsh soils was 12.6% greater than that in typical communities. Thus, the two plant species may use different strategies for Si accumulation and allocation in ecotones to adapt to the competitive environment. P. australis may expand primarily via occupation of wider aboveground space, thereby increasing the Si accumulation capacity in aboveground organs. Meanwhile, C. malaccensis may increase the Si allocation capacity of its roots to withstand the pressure from P. australis. This study will provide new insights into marsh plant competition from the perspective of Si, which can also benefit plant management in marsh ecosystems.

Methane Dynamics of Aquaculture Shrimp Ponds in Two Subtropical Estuaries, Southeast China: Dissolved Concentration, Net Sediment Release, and Water Oxidation

AbstractAquaculture ponds are potentially large sources of atmospheric methane (CH4) that can exacerbate climate change. A thorough understanding of various CH4 biogeochemical processes occurring in the ponds is essential for the prediction and management of CH4 emissions arising from aquaculture. However, the variations in pond CH4 biogeochemical processes among estuaries and aquaculture stages remain poorly understood. In this study, we assessed the net sediment release, oxidation, and dissolved concentrations of CH4 in aquaculture ponds in two subtropical estuaries among three shrimp growth stages in Southeast China. Overall, porewater CH4 concentrations and sediment CH4 release rates varied greatly among different stages in the order: middle stage &gt; final stage &gt; initial stage. Water column CH4 concentrations and overlying water CH4 oxidation rates showed an increasing trend over the study period. Sediment CH4 release rates and dissolved CH4 concentrations also varied considerably between the two estuaries. In the more saline Jiulong River Estuary, sediment CH4 release rate was lower while the shrimp survival rate and yield were higher as compared to the Min River Estuary with a lower water salinity. Our results suggest that both high water salinity and feed utilization efficiency can effectively mitigate CH4 emissions from the coastal shrimp ponds. Overall, the large magnitude of net CH4 emissions observed in our shrimp ponds highlights the urgency of formulating appropriate policies and building sustainable institutions that can strike a balance between land‐based aquaculture development and greenhouse gas mitigation in the subtropical coastal regions.

Microbiological Assessment of Ganga River, Bithoor, Kanpur Nagar, UP, India using Enteric Bacteria

One of the most valuable natural resources is water, which is also essential to a nation’s socioeconomic growth. Still, the most significant supply of surface water comes from rivers. India has an abundance of large, medium, and minor rivers with a combined catchment area of 252.8 million hectares. The biggest river basin in the Indian subcontinent is the Ganga basin. It originates in the state of Uttarakhand and spans more than one-fourth of the nation’s entire land area. About half of her population resides there. Approximately 50% of class 1 and class 2 towns in the nation are located in the Ganga basin, and the majority of these towns dump their municipal garbage into the river system. In and around the Bithoor Area in Kanpur Nagar, U.P., India, microbiological research was conducted on river Ganga pollution, and the level of pollution is being assessed.

Production and uptake of dissolved carbon, nitrogen, and phosphorus in overlying water of aquaculture shrimp ponds in subtropical estuaries, China.

Water quality deterioration can adversely affect the long-term sustainability of aquaculture industry. Understanding the processes of nutrient regeneration and uptake is important for improving water quality and the overall ecosystem health of aquaculture system. In spite of the importance of dissolved nutrients (DOC, DIC, N-NOx-, N-NH4+, and P-PO43-) in governing water quality and ecosystem functioning, the spatiotemporal variations in the production and uptake of dissolved nutrients in aquaculture ponds is still poorly understood. In this study, the nutrient production and uptake rates in the overlying water were quantified among different shrimp growth stages in the aquaculture ponds in the Min River Estuary (MRE) and Jiulong River Estuary (JRE), southeast China. Significant differences in the nutrient production and uptake rates in the overlying water were observed among the three growth stages and two estuaries. The temporal variations of DOC and DIC production rates in both estuarine ponds closely followed the seasonal cycle of temperature, while the difference in DOC and DIC production rates between the two estuaries was likely caused by differences in water salinity. The changes in the production and uptake rates of dissolved inorganic nitrogen (N-NOx- and N-NH4+) and P-PO43- in the water column over time were partly related to the interactions between thermal conditions and phytoplankton biomass (e.g., chlorophyll a concentrations) in the ponds. Our results demonstrate the complex dynamics and environmental risk of dissolved nutrients in subtropical shrimp ponds, and call for a more effective management of nutrient-laden wastewater in safeguarding the long-term sustainability of aquaculture production.

Metal accumulation in Asiatic clam from the Lower Min River (China) and implications for human health

Considering growing concerns regarding polluted estuaries and their adverse effects on public health, this study aimed to identify concentrations of metal (Zn, Fe, Cr, Ni, Cd, Mn, As, Cu, and Pb) in Asiatic clams sampled along the Lower Min River, China. Multivariate methods were used to identify and apportion pollution sources. Noncarcinogenic and carcinogenic health risk assessments were performed to gauge adverse consumer health effects. Results showed that Cr, Pb, and Zn concentrations were higher than the limits prescribed in Chinese government guidelines. In comparison with concentrations of selected metals in other rivers, Cr, Pb, Zn, and As concentrations in clams were generally higher. Pollution assessment using the metal pollution index showed that sampling sites surrounding developing industrial and residential areas were the most polluted. Principal component analysis indicated significant anthropogenic metal contributions in clams. Health risk assessment indicated significant risk for clam consumers along the Lower Min River in terms of hazard quotient and carcinogenic risk and, thus, clam consumption from the study area should be avoided. The present findings would help in establishing environmental monitoring plans and contribute to preserving public health as well as the development of water conservation strategies to alleviate the metal pollution.

Large Fine‐Scale Spatiotemporal Variations of CH4 Diffusive Fluxes From Shrimp Aquaculture Ponds Affected by Organic Matter Supply and Aeration in Southeast China

AbstractMariculture shrimp ponds are important CH4 sources to the atmosphere. However, the spatiotemporal variations of CH4 concentration and flux at fine spatial scales in mariculture ponds are poorly known, particularly in China, worlds largest aquaculture producer. In this study, the plot‐scale spatiotemporal variations of water CH4 concentration and flux, both within and among ponds, were researched in shrimp ponds in Shanyutan wetland, Min River Estuary, Southeast China. The average water CH4 concentration and diffusion flux across the water‐air interface in the shrimp ponds over the shrimp aquaculture period varied from 2.29 ± 0.29 to 50.48 ± 20.91 μM and from 0.09 ± 0.01 to 2.32 ± 0.95 mmol·m−2·hr−1, respectively. The CH4 emissions from the estuarine ponds varied greatly between seasons, with peaks in August and September, which was similar to the trend of water temperature and dissolved oxygen concentrations. There was no remarkable difference in CH4 concentration and flux between shrimp ponds but significantly spatiotemporal differences in CH4 concentration and flux within the ponds. Significantly higher emissions occurred in the feeding zone, accounting for approximately 60% of total CH4 emission flux, while much lower CH4 emissions appeared in aeration zone, contributing 14% to total flux. This study suggests the importance of considering spatiotemporal variation in the whole‐pond estimates of CH4 concentration and flux. In light of such high spatial variation within ponds, improving aeration and feed utilization efficiency would help to mitigate CH4 emissions from mariculture ponds.

Assessing the high impacts of land use change: spatial characteristics of land uses and ecological compensation based on payment for ecosystem services model in a mountainous area, China

Most impacts on ecosystem services (ESs) are related to land use changes that may cause ecosystem fragmentation and loss of ecosystem functions. Spatial planning focused on sustainable landscape development should consider the local potential for providing ESs as well as ecological conservation due to land use changes. To better address the issues that are related to ecological and the ecological and environmental conservation, ecological compensation could coordinate the development of the energy, the economy, and the environment by internalizing environmental externalities and adjusting for the relationships with stakeholders’ benefits. In this study, we developed a framework for analyzing the spatial characteristics of land uses and calculating ecological compensation based on pay for ecosystem services (PESs) from 1995 to 2010 in the upstream of Min River, China. In terms of lacunarity analysis, we firstly explored the spatial patterns of land uses in these two periods that occurred at different spatial characteristic scales. We also observed a strong relationship between lacunarity values and the different distribution patterns of land uses. We then investigated changes in ESs in response to land use change through the assignment of per unit area ecological service value (ESV) method. The total value of ESs dropped from 449.97 billion yuan in 1995 to 441.35 billion yuan in 2010, exhibiting decreasing rate, mainly due to the degradation of woodlands. Soil formation and retention, gas regulation, and biodiversity protection were the three largest ESs, contributing about 50% of the total ESV. Considering the changed relation between social and economic indicators and ESV based on spatial visualization and analysis, we finally constructed a quantitative estimate model for ecological compensation taking a village as study unit and determined standard value so as to evaluate ecological compensation from 1995 to 2010. Spatial differences of the ecological compensation were significant among all the villages and towns. The maximum ecological compensation account (ranged from 1.68 to 8.54 billion yuan) appeared in the villages approximated to Li County, Heishui County, and Songpan County, Sichuan, People’s Republic of China. This proposed framework provides a better understanding of spatial characteristic scales of land uses and enables evaluation of the ecological integrity of landscapes. It also fills up the gap in the field of quantitative evaluation of regional ecological compensation and provides a feasible way to reconcile the conflicts among benefits in the economic, social, and ecological sectors.

Sensitivity of Rural Households’ Livelihood Strategies to Livelihood Capital in Poor Mountainous Areas: An Empirical Analysis in the Upper Reaches of the Min River, China

Exploring the sensitivity of rural households’ livelihood strategies to livelihood capital is of great significance for improving rural households’ livelihood levels. This paper selects 23 livelihood capital measurement indicators and conducts an in-depth survey of rural households. In addition, the entropy method and a weighted comprehensive model are used to explore the basic characteristics of rural households’ livelihood capital in the upper reaches of the Min River, China, in 2017. Furthermore, econometric models are used to analyze the sensitivity of rural households’ livelihood strategies to livelihood capital. As indicated from the research, the livelihood capital levels of different types of rural households in the study area are not equivalent. The types of rural households with different livelihood strategies can be ordered in terms of quantity as follows: non-agricultural type &gt; non-agricultural dominant type &gt; agricultural dominant type &gt; pure agricultural type. Livelihood strategies have different sensitivities to different livelihood capital measurement indicators. Among these indicators, cash income, the number of relatives and friends available for financial assistance, and the number of civil servants have positive effects on the livelihood strategy selection of non-agricultural dominant rural households and non-agricultural rural households. However, the average age of laborers, area of cultivated land and gardens, number of livestock and poultry, and present value of production tools have negative effects. These evaluation results can provide a scientific decision-making basis for the formulation of poverty alleviation policies by relevant government departments.

Effects of nitrogen loading on emission of carbon gases from estuarine tidal marshes with varying salinity

Estuarine tidal marshes sequester significant quantities of carbon and are suffering from anthropogenic nitrogen (N) enhancement. However, the effects of this N loading on carbon gas emissions from freshwater-oligohaline tidal marshes are unknown. In this paper, we report on our evaluation of the effects of a N gradient (0, 24, 48 and 96 g NH4NO3–N m−2 y−1) on the methane (CH4) and carbon dioxide (CO2) emissions from freshwater and oligohaline tidal marshes in the Min River estuary, southeast China. On an annual scale, the oligohaline marsh has significantly higher CO2 emissions, while it has slightly lower CH4 emissions relative to freshwater marsh. The addition of N increased CH4 emission from the freshwater marsh and decreased CH4 emission from the oligohaline marsh, although there was no statistically significant difference in CH4 emission between either of the two marshes and the control. The addition of 96 g NH4NO3–N m−2 y−1 significantly increased CO2 emission from the freshwater marsh, while it did not significantly influence CO2 emission from the oligohaline marsh. CH4 and CO2 emission levels were positively correlated with soil temperature under all conditions. The CH4 flux resulting from both the control and the addition of N was negatively correlated with porewater SO42− and Cl− concentrations and soil EC in the oligohaline marsh. Overall, N addition significantly increased carbon gas emissions under freshwater conditions while slightly inhibiting carbon gas emissions from the oligohaline marsh. Our findings suggested that even under low salinity conditions, the effects of N loading on CH4 and CO2 emissions from freshwater and oligohaline tidal marshes can vary. We propose that the addition of N to estuarine tidal marshes has a significant effect on the carbon cycle and promotes soil carbon loss, phenomena which may be influenced by salinity.

From a river valley to a ria: Evolution of an incised valley (Ría de Ferrol, north‐west Spain) since the Last Glacial Maximum

AbstractThe evolution of incised valleys is an important area of research due to the invaluable data it provides on sea‐level variations and depositional environments. In this article the sedimentary evolution of the Ría de Ferrol (north‐west Spain) from the Last Glacial Maximum to the present is reconstructed using a multidisciplinary approach, combining seismic and sedimentary facies, and supported by radiocarbon data and geochemical proxies to distinguish the elements of sedimentary architecture within the ria infill. The main objectives are: (i) to analyse the ria environment as a type of incised valley to evaluate the response of the system to the different drivers; (ii) to investigate the major controlling factors; and (iii) to explore the differentiation between rias and estuaries. As a consequence of the sea‐level rise subsequent to the Last Glacial Maximum (ca 20 kyr bp), an extensive basin, drained by a braided palaeoriver, evolved into a tide‐dominated estuary and finally into a ria environment. Late Pleistocene and Holocene high‐frequency sea‐level variations were major factors that modulated the type of depositional environments and their evolution. Another major modulating factor was the antecedent morphology of the ria, with a rock‐incised narrow channel in the middle of the basin (the Ferrol Strait), which influenced the evolution of the ria as it became flooded during Holocene transgression. The strait acted as a rock‐bounded ‘tidal inlet’ enhancing the tidal erosion and deposition at both ends, i.e. with an ebb‐tidal delta in the outer sector and tidal sandbanks in the inner sector. The final step in the evolution of the incised valley into the modern‐defined ria system was driven by the last relative sea‐level rise (after 4 kyr bp) when the river mouths retreated landward and a single palaeoriver was converted into minor rivers and streams with scattered mouths in an extensive coastal area.

Carbon dioxide dynamics from sediment, sediment-water interface and overlying water in the aquaculture shrimp ponds in subtropical estuaries, southeast China

Aquaculture ponds can emit a large amount carbon dioxide (CO2), with the consequence of exacerbating global climate change. Many studies about CO2 dynamics across the water-air interface, but CO2 in sediment and overlying water received relative less attention. In this study, CO2 concentration in sediment porewater, the diffusive CO2 fluxes across the sediment-water interface (SWI), and the CO2 production rates in the overlying water (CO2_WP) were determined in the shrimp ponds in the Min River Estuary (MRE) and Jiulong River Estuary (JRE), southeast China, to analyze the dynamics of CO2 among different growth stages of shrimps. Our results showed large variations in porewater CO2 concentrations, CO2 diffusive fluxes and CO2_WP rates among different growth stages, with markedly larger values in the middle stage of shrimp growth. The temporal variation of CO2 in both estuarine ponds followed closely the seasonal change of temperature. The internal CO2 production (CO2_IP) in these ponds was dominated by sediments. A significantly larger mean porewater CO2 concentrations, diffusive fluxes and production rate were observed in the MRE ponds than those in the JRE ponds, which could be attributed to the lower water salinity and a larger source of carbon substrates in the former estuary. Considering a total surface area of 6.63 × 103 km2 across the mariculture ponds in subtropical estuaries, it is estimated conservatively that approximately 100 Gigagram (Gg) of dissolved organic carbon and 190 Gg of dissolved inorganic carbon were transported annually from the mariculture ponds into China's coastal areas. Because of the substantial supply of dissolved carbon, the adjacent coastal waters receiving effluent discharge from the mariculture ponds could become “hotspots” of CO2 emissions. Our results highlight the role of aquaculture pond as a major CO2 source in China's coastal areas, and effective actions are needed to alleviate the greenhouse gas (GHG) emissions from these ponds.

Plot-scale spatiotemporal variations of CO2 concentration and flux across water-air interfaces at aquaculture shrimp ponds in a subtropical estuary.

Human activities have increased anthropogenic CO2 emissions, which are believed to play important roles in global warming. The spatiotemporal variations of CO2 concentration and flux at fine spatial scales in aquaculture ponds remain unclear, particularly in China, the country with the largest aquaculture. In this study, the plot-scale spatiotemporal variations of water CO2 concentration and flux, both within and among ponds, were researched in shrimp ponds in Shanyutan Wetland, Min River Estuary, Southeast China. The average water CO2 concentration and flux across the water-air interface in the shrimp ponds over the shrimp farming period varied from 22.79 ± 0.54 to 186.66 ± 8.71μmolL-1 and from - 0.50 ± 0.04 to 2.87 ± 0.78molm-2day-1, respectively. There was no remarkable difference in CO2 concentration and flux within the ponds, but significantly spatiotemporal differences in CO2 flux were observed between shrimp ponds. Chlorophyll a, pH, salinity, air temperature, and morphometry were the important factors driving the spatiotemporal patterns of CO2 flux in the shrimp ponds. Our findings highlighted the importance and spatiotemporal variations of CO2 flux in the important coastal ecosystems.

基于地理探测器的岷江中下游地区植被NPP时空格局演变及其驱动力研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于地理探测器的岷江中下游地区植被NPP时空格局演变及其驱动力研究 DOI: 10.5846/stxb201809131971 作者: 作者单位: 四川师范大学西南土地资源评价与监测教育部重点实验室,四川师范大学西南土地资源评价与监测教育部重点实验室,四川师范大学西南土地资源评价与监测教育部重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41371125）；教育部规划基金项目（18XJA630005）；四川省社科项目（SC18B095） The spatial and temporal pattern evolution of vegetation NPP and its driving forces in middle-lower areas of the Min river based on geographical detector analyses Author: Affiliation: Key Laboratory of Land Resources Evaluation and Monitoring in Southwest,Ministry of Education,Sichuan Normal University,Key Laboratory of Land Resources Evaluation and Monitoring in Southwest,Ministry of Education,Sichuan Normal University,Key Laboratory of Land Resources Evaluation and Monitoring in Southwest,Ministry of Education,Sichuan Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植被净初级生产力作为反映植被生态系统对气候变化响应的重要指标，是长期以来备受世界各国关注的焦点问题。论文以岷江中下游地区为研究区域，基于2000-2015年MODIS NPP数据，结合同年期海拔、气温、降水、土地利用类型等，运用地理探测器等模型方法，诊断植被NPP分布的主要驱动力，并揭示了不同时段的驱动力决定力的变化。结果表明：（1）2000-2015年岷江中下游植被NPP平均值为513.93gC/m2；植被年均NPP最大值出现在2000年石棉县北部硗碛藏族乡的林地分布区，为1876gC/m2，最小值出现在2005年五通桥区中部竹根镇的平原旱地分布区，最小值为26.98gC/m2；植被NPP具有较强的时空分异性，NPP总量变化除了受NPP强度影响外，植被覆盖总面积是其另外主要的影响因素。（2）影响植被NPP分布的主导因素包括气温、海拔、土地利用等，各因素对NPP分布的决定力存在明显差异。（3）不同时间植被NPP空间分布的驱动力存在明显差异，主要表现在其变化受人类扰动的影响越来越强烈。刻画岷江中下游植被NPP时空演变，并揭示其主要驱动力，可为研究区生态安全预警和生态补偿提供数据支撑和辅助决策。 Abstract:Vegetation net primary productivity (NPP) is considered a key factor of ecological responses to climate change, so it has long aroused attention from countries around the world. Using the middle-lower Area of the Min river as the study area, the Geodetector model was applied based on MODIS NPP products from 2000 to 2015, as well as annual altitude, temperature, precipitation, and land use date in the same period to diagnose the dominant factors of spatial distribution of vegetation NPP change and reveal the different time changes of driving forces determining vegetation NPP differentiation. The results showed that 1) The average annual NPP for the middle-lower Area of the Min river was 513.93 gC/m2 from 2000 to 2015. The maximum and minimum values (1876 gC/m2 and 26.98 gC/m) observed in 2000 in the Qiaoqi Tibetan township north of Shimian county and 2005 in the plain dryland distribution area of Zhugen Town in the middle of Wutongqiao showed a strong spatiotemporal variability in the middle-lower Area of the Min river. In addition to the NPP intensity, the total area covered by vegetation was the other major influencing factor. 2) The dominant factors affecting vegetation NPP spatial distribution included temperature, altitude, and land use, and their power determinant value to NPP incidence differentiation. 3) These factors affect the changes in vegetation NPP from different perspectives and their driving forces differ over the years. The changes in vegetation NPP mainly presented more and more concerned by human disturbances. On the contrary, it is weakened by natural factors. Spatiotemporal changes of NPP and its driving forces were revealed. The findings provided the data and assistant decision-making for the government to formulate policies regarding ecological security alarm and ecological compensation. 参考文献 相似文献 引证文献

闽江口互花米草淤积作用对其自身和短叶茳芏残体分解及硫养分释放的影响

闽江口互花米草淤积作用对其自身和短叶茳芏残体分解及硫养分释放的影响

闽江口芦苇与短叶茳芏湿地土壤无机硫形态分布特征及其影响因素

闽江口芦苇与短叶茳芏湿地土壤无机硫形态分布特征及其影响因素

Spatial priority conservation areas for vegetation habitat across the Upper Reaches of Min River located in Sichuan Province, China

Considered as a hotspot for biodiversity in the upstream of Yangtze River, many vegetation habitats have been seriously damaged in Upper Reaches of Min River located in Sichuan Province, China due to the continuous deterioration of ecosystems. This work aims to define important protected areas with higher vegetation habitat suitability index. Through integrating the spatial distribution of vegetation habitat suitability (HS) index into systematic conservation planning, this study constructed spatial priority conservation areas of vegetation habitat under different protection targets in the Upper Reaches of Min River, China. In this regard, effective information regarding vegetation HS and its priority conservation planning responded to conservation target level changes and boundary length effect provide useful support for diverse stakeholders in vegetation habitat planning, management and policies. The southeastern places played an important role in the priority conservation areas for vegetation habitat, and there were more conservation areas located in east of study site than west. As increasing of target levels (ranged 10%–90% percentages of summing amount for vegetation HS index at watershed scale), the spatial priority conservation areas for vegetation habitat gradually extended from the south to the north. The spatial structure of priority conservation areas for vegetation habitat with boundary length effect was more compact than that without boundary length effect. The total priority conservation areas with boundary length effect were approximate to those without boundary length effect, but the total boundary length of former was far less than that of latter. It suggested that integrating boundary length effect to systematic conservation planning of vegetation habitat could produce more aggregated conservation patches and increase connectivity among patches. The total priority conservation areas for vegetation habitat were traded off against total boundary length of reserve networks. It indicated that this tradeoff information could help stakeholder to reasonably allocate investment to maintain reserve network under different target levels. The proposed approach could provide useful information to assess the responses of priority conservation areas for vegetation habitat to different protected targets and boundary length effect, and also guarantee ecosystem sustainability across watershed.