With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that： the soil total porosi...With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that： the soil total porosity was the highest in the Casuarina equisetifolia forest （46.168%）, but the lowest in the Encalyptus robusta forest （39.46%）. The soil capillary porosity was the highest in the Acacia mangium forest （22.57%）, but the lowest in the secondary forest （18.95%）. The soil water content was the highest in the C. equisetifolia forest, with a mean value of 27.85%, but the lowest in the secondary forest, with a mean value of 4.34%. The soil pH values were in the range of 4.81-6.59, the soils in the A. mangium forest, C. equisetifolia forest and E. robusta forest were strongly acidic （pH 4.5-5.5）, and the soils in the secondary forest and C. nucifera forest were weakly acidic. The soils had organic matter contents in the range of 0.34-28.68 g/kg, and showed an order of A. mangium forest〉C. equisetifolia forest〉E. robusta forest〉secondary forest〉C. nucifera forest, with a decreasing trend with the soil depth increasing. The soil total N contents were in the range of 0.10-1.63 g/kg, the A. mangium forest showed the highest soil total N contents, while the C. nucifera forest exhibited the lowest soil total N contents; the soil total P contents were in the range of 0.21-1.74 g/kg, and the E. robusta forest had the highest soil total P contents; and the soil total K contents were in the range of 0.16-2.15 g/kg, and the A. mangium forest exhibited the highest soil total K contents. The soil available P contents were in the range of 0.98-132.46 mg/kg; and the secondary forests had the highest soil available P contents; and the soil rapidly available K contents were in the range of 3.03-27.35 mg/kg, and the C. nucifera forest exhibited the highest soil rapidly available K contents. The soil ammonium N contents were in the range of 1.38-5.15 mg/kg, and the nitrate N contents were in the range were in the range of 0.56 -3.51 mg/kg. The A. mangium forest showed the highest soil nitrate N contents （with a mean value of 2.29 mg/kg） and ammonium N contents （with a mean value of 3.93 mg/kg）. For the same forest type, with the increase of soil depth, the nitrate nitrogen and ammonium nitrogen content also showed a decreasing trend.展开更多
Rural poverty and poverty reduction are not only the focal issues that have attracted worldwide attention, but also the vital issues on people's livelihood that has attached great importance and aimed to be solved...Rural poverty and poverty reduction are not only the focal issues that have attracted worldwide attention, but also the vital issues on people's livelihood that has attached great importance and aimed to be solved by the central and local governments of China. Based on the survey data of 354 farming households, this paper, taking the national poverty county of Lingao County, Hainan Province for an example, examined the characteristics of rural poverty of the county. Moreover, this paper established the spatial lag model(SLM) from five dimensions, namely, status of the household head, household structure, health status, income composition and traffic accessibility, to analyze the main influencing factors of rural poverty according to the values of Moran's I and the diagnosis of spatial dependence of the OLS model. It is found that the poor farming households gathered mainly in five towns in the north and southwest of the county, and the rural poverty have the characteristics of low educational level of the heads, more minor children, high population of farming peasants, high incidence of disease and low proportion of household wage-equivalent income. The results also showed that the variables such as the number of minor children, the number of migrant worker, the number of farming peasants and the proportion of wage-equivalent income have significant effectiveness on rural poverty, while the status of the household head, health status and traffic accessibility have little influence. It is an important way to realize the goal of poverty alleviation by controlling the number of farmers' fertility, strengthening the vocational skills training of farmers, vigorously developing specialization and large-scale agriculture and increasing the employment opportunities of farmers.展开更多
为查明海南临高红牌—马袅沿岸海域造礁石珊瑚群落结构及其环境因子,于2023年3月18—23日对该区域开展造礁石珊瑚群落、底质类型、悬浮物沉降速率和水环境因子调查。结果显示:(1)本区域造礁石珊瑚共鉴定13科24属42种和7未定种,其覆盖率...为查明海南临高红牌—马袅沿岸海域造礁石珊瑚群落结构及其环境因子,于2023年3月18—23日对该区域开展造礁石珊瑚群落、底质类型、悬浮物沉降速率和水环境因子调查。结果显示:(1)本区域造礁石珊瑚共鉴定13科24属42种和7未定种,其覆盖率均值为(18.05±10.53)%,集中分布在水深1.0~2.5m;(2)造礁石珊瑚优势种以团块状或皮壳状生长型为主,死造礁石珊瑚覆盖率(>2年)与活造礁石珊瑚覆盖率、Shannon多样性指数呈显著负相关,而Shannon多样性指数与Simpson优势度指数和Pielou均匀度指数呈显著正相关,这表明伴随造礁石珊瑚的死亡,其覆盖率和物种多样性显著降低;(3)死造礁石珊瑚覆盖率与砂质底覆盖率呈显著正相关,而与pH呈显著负相关;Pielou均匀度指数与溶解氧和悬浮物沉积物速率呈显著负相关性;水体浊度与光合有效辐射漫衰减系数Kd-PAR(diffuse attenuation coefficient of the photosynthetically active radiation)呈显著正相关,且其均值(3.81±1.10)NTU(nephelometric turbidity unit)已超过影响造礁石珊瑚生长的胁迫阈值(3NTU)。这些结果表明,海底砂质覆盖率、悬浮物沉降速率、浊度、pH、溶解氧和Kd-PAR等是影响该海域造礁石珊瑚群落结构的重要环境因子。综上,临高红牌—马袅沿岸海域是造礁石珊瑚分布热点之一,具有较高物种多样性和覆盖率。然而,该区域造礁石珊瑚垂直分布范围较窄,且正面临多重环境因子胁迫,需要采取有效措施进行及时保护。展开更多
基金Supported by Special Fund for Technological Development and Research of Provincial Scientific Research Institutions(KYYS-2015-16)~~
文摘With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that： the soil total porosity was the highest in the Casuarina equisetifolia forest （46.168%）, but the lowest in the Encalyptus robusta forest （39.46%）. The soil capillary porosity was the highest in the Acacia mangium forest （22.57%）, but the lowest in the secondary forest （18.95%）. The soil water content was the highest in the C. equisetifolia forest, with a mean value of 27.85%, but the lowest in the secondary forest, with a mean value of 4.34%. The soil pH values were in the range of 4.81-6.59, the soils in the A. mangium forest, C. equisetifolia forest and E. robusta forest were strongly acidic （pH 4.5-5.5）, and the soils in the secondary forest and C. nucifera forest were weakly acidic. The soils had organic matter contents in the range of 0.34-28.68 g/kg, and showed an order of A. mangium forest〉C. equisetifolia forest〉E. robusta forest〉secondary forest〉C. nucifera forest, with a decreasing trend with the soil depth increasing. The soil total N contents were in the range of 0.10-1.63 g/kg, the A. mangium forest showed the highest soil total N contents, while the C. nucifera forest exhibited the lowest soil total N contents; the soil total P contents were in the range of 0.21-1.74 g/kg, and the E. robusta forest had the highest soil total P contents; and the soil total K contents were in the range of 0.16-2.15 g/kg, and the A. mangium forest exhibited the highest soil total K contents. The soil available P contents were in the range of 0.98-132.46 mg/kg; and the secondary forests had the highest soil available P contents; and the soil rapidly available K contents were in the range of 3.03-27.35 mg/kg, and the C. nucifera forest exhibited the highest soil rapidly available K contents. The soil ammonium N contents were in the range of 1.38-5.15 mg/kg, and the nitrate N contents were in the range were in the range of 0.56 -3.51 mg/kg. The A. mangium forest showed the highest soil nitrate N contents （with a mean value of 2.29 mg/kg） and ammonium N contents （with a mean value of 3.93 mg/kg）. For the same forest type, with the increase of soil depth, the nitrate nitrogen and ammonium nitrogen content also showed a decreasing trend.
基金Under the auspices of National Natural Science Foundation of China(No.41661028)Natural Science Foundation of Hainan(No.417099)Science and Technology Plan Project of Colleges and Universities of Shandong(No.J14LH04)
文摘Rural poverty and poverty reduction are not only the focal issues that have attracted worldwide attention, but also the vital issues on people's livelihood that has attached great importance and aimed to be solved by the central and local governments of China. Based on the survey data of 354 farming households, this paper, taking the national poverty county of Lingao County, Hainan Province for an example, examined the characteristics of rural poverty of the county. Moreover, this paper established the spatial lag model(SLM) from five dimensions, namely, status of the household head, household structure, health status, income composition and traffic accessibility, to analyze the main influencing factors of rural poverty according to the values of Moran's I and the diagnosis of spatial dependence of the OLS model. It is found that the poor farming households gathered mainly in five towns in the north and southwest of the county, and the rural poverty have the characteristics of low educational level of the heads, more minor children, high population of farming peasants, high incidence of disease and low proportion of household wage-equivalent income. The results also showed that the variables such as the number of minor children, the number of migrant worker, the number of farming peasants and the proportion of wage-equivalent income have significant effectiveness on rural poverty, while the status of the household head, health status and traffic accessibility have little influence. It is an important way to realize the goal of poverty alleviation by controlling the number of farmers' fertility, strengthening the vocational skills training of farmers, vigorously developing specialization and large-scale agriculture and increasing the employment opportunities of farmers.
文摘为查明海南临高红牌—马袅沿岸海域造礁石珊瑚群落结构及其环境因子,于2023年3月18—23日对该区域开展造礁石珊瑚群落、底质类型、悬浮物沉降速率和水环境因子调查。结果显示:(1)本区域造礁石珊瑚共鉴定13科24属42种和7未定种,其覆盖率均值为(18.05±10.53)%,集中分布在水深1.0~2.5m;(2)造礁石珊瑚优势种以团块状或皮壳状生长型为主,死造礁石珊瑚覆盖率(>2年)与活造礁石珊瑚覆盖率、Shannon多样性指数呈显著负相关,而Shannon多样性指数与Simpson优势度指数和Pielou均匀度指数呈显著正相关,这表明伴随造礁石珊瑚的死亡,其覆盖率和物种多样性显著降低;(3)死造礁石珊瑚覆盖率与砂质底覆盖率呈显著正相关,而与pH呈显著负相关;Pielou均匀度指数与溶解氧和悬浮物沉积物速率呈显著负相关性;水体浊度与光合有效辐射漫衰减系数Kd-PAR(diffuse attenuation coefficient of the photosynthetically active radiation)呈显著正相关,且其均值(3.81±1.10)NTU(nephelometric turbidity unit)已超过影响造礁石珊瑚生长的胁迫阈值(3NTU)。这些结果表明,海底砂质覆盖率、悬浮物沉降速率、浊度、pH、溶解氧和Kd-PAR等是影响该海域造礁石珊瑚群落结构的重要环境因子。综上,临高红牌—马袅沿岸海域是造礁石珊瑚分布热点之一,具有较高物种多样性和覆盖率。然而,该区域造礁石珊瑚垂直分布范围较窄,且正面临多重环境因子胁迫,需要采取有效措施进行及时保护。
