China’s 13 th 5-year forestry plan explicitly requires the end of commercial harvesting and the improved management of natural forests by means of adjusting and optimizing forest structure and developing high-quality...China’s 13 th 5-year forestry plan explicitly requires the end of commercial harvesting and the improved management of natural forests by means of adjusting and optimizing forest structure and developing high-quality forest production.This requires the quantification of stand structure and species diversity.In this study,species distribution,association and size differentiation in a mixed broad-leaved/Korean pine(Pinus koraiensis Siebold&Zucc.)forest in Mudanfeng National Nature Reserve were analyzed using three spatial structure indices:uniform angle index,complete mingling index,and size differentiation index.The results show that the species were randomly distributed,with a moderate size differentiation and high mixed structure.Three dominant species exhibited different patterns in terms of the three indices and their bivariate distribution.Overall,Korean pine showed an opposite trend to Manchurian maple(Acer mandshuricum Maxim.),whereas the distribution pattern of Manchurian linden(Tilia mandshurica Rupr.&Maxim.)was similar to that of the entire stand.Our work contributes to further the knowledge of population structure in order to optimize the structure of secondary forests and plantations.展开更多
Atmospheric deposition(dry and wet deposition)is one of the primary sources of chemical inputs to terrestrial ecosystems and replenishes the nutrient pool in forest ecosystems.Precipitation often acts as a primary tra...Atmospheric deposition(dry and wet deposition)is one of the primary sources of chemical inputs to terrestrial ecosystems and replenishes the nutrient pool in forest ecosystems.Precipitation often acts as a primary transporting agent and solvent;thus,nutrient cycles in forests are closely linked to hydrological processes.We collected precipitation data during a growing season to explore variations in nutrient cycling and nutrient balances in the rainfall redistribution process(wet deposition)in a larch plantation in northeast China.We measured nutrient(NO_(3)^(-),PO_(4)^(3−),Cl^(−),K,Ca,Na,and Mg)inputs via bulk precipitation,throughfall and stemfl ow,and used a canopy budget model to estimate nutrient fl uxes via canopy exchange.Our results suggest that the average concentrations of the base cation(K,Ca,Na,and Mg)showed the following order:stemfl ow>throughfall>bulk precipitation.Throughfall and stemfl ow chemistry dramatically fl uctuated over the growing season when net fl uxes(throughfall+stemfl ow—bulk precipitation)of NO−3,PO3−4,SO2−4,Cl−,K,Ca,Na,and Mg were−6.676 kg·ha^(-1),−1.094 kg·ha^(-1),−2.371 kg·ha^(-1),1.975 kg·ha^(-1),0.470 kg·ha^(-1),−5.202 kg·ha^(-1),−0.336 kg·ha^(-1),and 1.397 kg·ha^(-1),respectively.These results suggest that NO−3,PO3−4,SO2−4,Ca,and Na were retained,while Cl−,K,and Mg were washed off by throughfall and stemfl ow.展开更多
A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a larg...A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a large watershed, northeast China. Cumulative forest cover increased by 22 %, leading to a significant decrease in estimated annual water yield. Reforestation increased ET （P = 0.0144）, resulting in a remarkable decrease （P = 0.0001） in estimated annual water yield according to the water balance model. Reforestation increased ET by 33 mm and decreased annual water yield by 38 mm per decade. The effect of reforestation on annual water yield can be quantified using a simplified water balance model in a large watershed, although our reforestation area was small （about 20 %） in relation to the total watershed area.展开更多
Several indices and simple empirical models and ratios of single band from pre-and post-fire Landsat images have been developed to estimate and/or map burn severity.However,these models and indices are usually site-,t...Several indices and simple empirical models and ratios of single band from pre-and post-fire Landsat images have been developed to estimate and/or map burn severity.However,these models and indices are usually site-,time-and vegetation-dependent and their applications are limited.The Daxing'an Mountains range has the largest forested area in China and is prone to wildfires.Whether or not the existing models can effectively characterize the burn severity over a large region is unclear.In this study,we used the orthogonal signal correction method based on partial least squares regression(PLSR)to select those variables that better interpret the variance of burn severity.A new index and other commonly used indices were used to construct a new,multivariate PLSR model which was compared with the popular single variable models,according to three assessment indices:relative root mean square error(RMSE%),relative bias(R E%)and Nash–Sutcliffe efficiency(NSE%).The results indicate that the multivariate PLSR model performed better than the other single variable models with higher NSE%(68.2%vs.67.8%)and less RE%(3.7%vs.-8.7%),while achieving almost the same R MSE%.We also discuss the spectral characteristics of the four selected variables for constructing the multivariate PLSR model and their correlation with the field burn severity data.The new model developed from this study should help to better understand the patterns of forest burn severity and assist in vegetation restoration efforts in the region.展开更多
By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing...By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.展开更多
基金financially supported by the National Key R&D Program of China(2018YFC0507302-2)the CFERN and BEIJING TECHNO SOLUTIONS Award Funds for excellent academic achievement
文摘China’s 13 th 5-year forestry plan explicitly requires the end of commercial harvesting and the improved management of natural forests by means of adjusting and optimizing forest structure and developing high-quality forest production.This requires the quantification of stand structure and species diversity.In this study,species distribution,association and size differentiation in a mixed broad-leaved/Korean pine(Pinus koraiensis Siebold&Zucc.)forest in Mudanfeng National Nature Reserve were analyzed using three spatial structure indices:uniform angle index,complete mingling index,and size differentiation index.The results show that the species were randomly distributed,with a moderate size differentiation and high mixed structure.Three dominant species exhibited different patterns in terms of the three indices and their bivariate distribution.Overall,Korean pine showed an opposite trend to Manchurian maple(Acer mandshuricum Maxim.),whereas the distribution pattern of Manchurian linden(Tilia mandshurica Rupr.&Maxim.)was similar to that of the entire stand.Our work contributes to further the knowledge of population structure in order to optimize the structure of secondary forests and plantations.
基金supported financially by the Natural Science Foundation of Heilongjiang Province of China(LH2020C032)the Fundamental Research Funds for the Central Universities(No.2572018BA10)。
文摘Atmospheric deposition(dry and wet deposition)is one of the primary sources of chemical inputs to terrestrial ecosystems and replenishes the nutrient pool in forest ecosystems.Precipitation often acts as a primary transporting agent and solvent;thus,nutrient cycles in forests are closely linked to hydrological processes.We collected precipitation data during a growing season to explore variations in nutrient cycling and nutrient balances in the rainfall redistribution process(wet deposition)in a larch plantation in northeast China.We measured nutrient(NO_(3)^(-),PO_(4)^(3−),Cl^(−),K,Ca,Na,and Mg)inputs via bulk precipitation,throughfall and stemfl ow,and used a canopy budget model to estimate nutrient fl uxes via canopy exchange.Our results suggest that the average concentrations of the base cation(K,Ca,Na,and Mg)showed the following order:stemfl ow>throughfall>bulk precipitation.Throughfall and stemfl ow chemistry dramatically fl uctuated over the growing season when net fl uxes(throughfall+stemfl ow—bulk precipitation)of NO−3,PO3−4,SO2−4,Cl−,K,Ca,Na,and Mg were−6.676 kg·ha^(-1),−1.094 kg·ha^(-1),−2.371 kg·ha^(-1),1.975 kg·ha^(-1),0.470 kg·ha^(-1),−5.202 kg·ha^(-1),−0.336 kg·ha^(-1),and 1.397 kg·ha^(-1),respectively.These results suggest that NO−3,PO3−4,SO2−4,Ca,and Na were retained,while Cl−,K,and Mg were washed off by throughfall and stemfl ow.
基金financially supported by the State Forestry Administration of China(201404201)the Guangxi Natural Science Foundation of China(2012GXNSFBA053140)+2 种基金the Fundamental Research Funds of Guangxi Academy of Sciences(13YJ22ZWS22)the Guangxi Institute of Botany(12001)CFERN&GENE Award Funds on Ecological Paper
文摘A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a large watershed, northeast China. Cumulative forest cover increased by 22 %, leading to a significant decrease in estimated annual water yield. Reforestation increased ET （P = 0.0144）, resulting in a remarkable decrease （P = 0.0001） in estimated annual water yield according to the water balance model. Reforestation increased ET by 33 mm and decreased annual water yield by 38 mm per decade. The effect of reforestation on annual water yield can be quantified using a simplified water balance model in a large watershed, although our reforestation area was small （about 20 %） in relation to the total watershed area.
基金partially supported by the Fundamental Research Funds for the Central Universities(DL12CA12,2572017PZ05)in part by the Research Foundation for Junior Teachers from the Ministry of Education of China(20110062120010)。
文摘Several indices and simple empirical models and ratios of single band from pre-and post-fire Landsat images have been developed to estimate and/or map burn severity.However,these models and indices are usually site-,time-and vegetation-dependent and their applications are limited.The Daxing'an Mountains range has the largest forested area in China and is prone to wildfires.Whether or not the existing models can effectively characterize the burn severity over a large region is unclear.In this study,we used the orthogonal signal correction method based on partial least squares regression(PLSR)to select those variables that better interpret the variance of burn severity.A new index and other commonly used indices were used to construct a new,multivariate PLSR model which was compared with the popular single variable models,according to three assessment indices:relative root mean square error(RMSE%),relative bias(R E%)and Nash–Sutcliffe efficiency(NSE%).The results indicate that the multivariate PLSR model performed better than the other single variable models with higher NSE%(68.2%vs.67.8%)and less RE%(3.7%vs.-8.7%),while achieving almost the same R MSE%.We also discuss the spectral characteristics of the four selected variables for constructing the multivariate PLSR model and their correlation with the field burn severity data.The new model developed from this study should help to better understand the patterns of forest burn severity and assist in vegetation restoration efforts in the region.
基金supported by the Fundamental Research Funds for the Central Universities(DL13BAX10)the Natural Science Foundation of Heilongjiang Province of China(QC2013C037)the assisted project by Heilongjiang Postdoctoral Funds for Scientific Research Initiation(LBH-Q13006)
文摘By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.
