Accurate assessment of site quality in coastal Casuarina equisetifolia(C.equisetifolia)plantations is essential for enhancing the protective function of shelterbelts and implementing site-specific afforestation strate...Accurate assessment of site quality in coastal Casuarina equisetifolia(C.equisetifolia)plantations is essential for enhancing the protective function of shelterbelts and implementing site-specific afforestation strategies.However,traditional ground-based surveys are limited in spatial coverage and efficiency,hindering effective forest management.To overcome these limitations,this study developed an integrated assessment framework that couples ground-based modeling with remote sensing inversion to achieve large-scale site quality mapping.Field investigations on Pingtan Island,Fujian Province,China,were used to establish a ground-based evaluation model.Soil fertility was quantified using Principal Component Analysis(PCA),and principal components were classified into discrete fertility grades through K-means clustering.These grades,together with topographic variables,were incorporated into a site quality classification model constructed using Quantification Theory I.The point-based model was subsequently extrapolated using Landsat 9 imagery to generate a spatially continuous site quality map.Spatial autocorrelation(Moran’s Ⅰ)and LISA clustering were further employed to interpret spatial patterns.Results indicate that coastal sandy soils in the study area are generally nutrient-poor,with tree growth primarily constrained by total nitrogen,organic matter,available phosphorus,and total phosphorus.The five most influential site factors,ranked by importance,are soil fertility,distance from the coastline,aspect,slope gradient,and elevation.Optimal conditions for C.equisetifolia growth include fertile soil,location>1000 m from the coastline,south-facing or semi-sunny slopes,slope gradients<15°,and elevations between 10-100 m.Only 11.94%of the area was classified as high-quality(Grade I),while 61.74%fell into moderate or poor grades(Grades Ⅲ and Ⅳ),indicating that most plantations are located on suboptimal sites.This study provides scientific support for improving the precision and sustainability of coastal shelterbelt planning and management,offering practical insights for afforestation strategies,forest restoration,and ecological forestry development in coastal zones.展开更多
Cyperus esculentus(C.esculentus),a desert-adapted plant species with both ecological and economic value,has been widely cultivated in northern China's sandy regions.However,limited studies have investigated the pe...Cyperus esculentus(C.esculentus),a desert-adapted plant species with both ecological and economic value,has been widely cultivated in northern China's sandy regions.However,limited studies have investigated the performance of composite shelterbelts that integrate C.esculentus.This study systematically evaluated five shelterbelt models—Populus euphratica(P.euphratica),P.euphratica–C.esculentus composite,P.euphratica–nylon net–C.esculentus composite,Tamarix chinensis(T.chinensis),and T.chinensis–C.esculentus composite—using wind tunnel experiments and field observations.Sediment flux was measured at a normalized downwind distance(x/h)of 5,where x refers to the distance from the front edge(upwind side)of the shelterbelt for upwind measurements,and the distance from the rear edge(downwind side)for downwind measurements,and h represents the canopy height.Wind velocity was measured at x/h of–2,–1,1,2,3,5,and 7,and sand flux was measured at x/h=5,under initial wind velocities of 8.0 and 12.0 m/s.The results indicated that the P.euphratica–nylon net–C.esculentus composite was the most effective in reducing wind velocity,followed by the P.euphratica–C.esculentus composite.In contrast,the P.euphratica and T.chinensis exhibited relatively weaker wind reduction capabilities.Regarding sand flux,under moderate wind velocity(8.0 m/s),both the P.euphratica–C.esculentus composite and P.euphratica–nylon net–C.esculentus composite demonstrated the lowest sand flux values.However,under high wind velocity(12.0 m/s),the P.euphratica–nylon net–C.esculentus composite significantly outperformed the other shelterbelt models in sand retention,highlighting its superior windbreak and sand fixation efficacy.Field observations further validated the windbreak and sand fixation effects of C.esculentus.Comparisons between the bare sand plot and C.esculentus plot within protective forests demonstrated that planting C.esculentus can provide substantial ecological benefits in windbreak and sand-fixation.These findings,reinforced by field observations,strengthen the wind tunnel experiment results and highlight the critical role of C.esculentus in enhancing the performance of composite shelterbelts for desert ecological restoration.展开更多
基金supported by University Key Lab for Geomatics Technology&Optimize Resources Utilization in Fujian Province(KJG20104A)Fujian Forestry Science and Technology project(2023FKJ15)Fuzhou Forestry Science and Technology Research Project(2130206).
文摘Accurate assessment of site quality in coastal Casuarina equisetifolia(C.equisetifolia)plantations is essential for enhancing the protective function of shelterbelts and implementing site-specific afforestation strategies.However,traditional ground-based surveys are limited in spatial coverage and efficiency,hindering effective forest management.To overcome these limitations,this study developed an integrated assessment framework that couples ground-based modeling with remote sensing inversion to achieve large-scale site quality mapping.Field investigations on Pingtan Island,Fujian Province,China,were used to establish a ground-based evaluation model.Soil fertility was quantified using Principal Component Analysis(PCA),and principal components were classified into discrete fertility grades through K-means clustering.These grades,together with topographic variables,were incorporated into a site quality classification model constructed using Quantification Theory I.The point-based model was subsequently extrapolated using Landsat 9 imagery to generate a spatially continuous site quality map.Spatial autocorrelation(Moran’s Ⅰ)and LISA clustering were further employed to interpret spatial patterns.Results indicate that coastal sandy soils in the study area are generally nutrient-poor,with tree growth primarily constrained by total nitrogen,organic matter,available phosphorus,and total phosphorus.The five most influential site factors,ranked by importance,are soil fertility,distance from the coastline,aspect,slope gradient,and elevation.Optimal conditions for C.equisetifolia growth include fertile soil,location>1000 m from the coastline,south-facing or semi-sunny slopes,slope gradients<15°,and elevations between 10-100 m.Only 11.94%of the area was classified as high-quality(Grade I),while 61.74%fell into moderate or poor grades(Grades Ⅲ and Ⅳ),indicating that most plantations are located on suboptimal sites.This study provides scientific support for improving the precision and sustainability of coastal shelterbelt planning and management,offering practical insights for afforestation strategies,forest restoration,and ecological forestry development in coastal zones.
基金supported by the Xinjiang Key Research and Development Programme Project(2022B02040-2)the Tianshan Yingcai Program of Xinjiang Uygur Autonomous Region(2024TSYCLJ0028).
文摘Cyperus esculentus(C.esculentus),a desert-adapted plant species with both ecological and economic value,has been widely cultivated in northern China's sandy regions.However,limited studies have investigated the performance of composite shelterbelts that integrate C.esculentus.This study systematically evaluated five shelterbelt models—Populus euphratica(P.euphratica),P.euphratica–C.esculentus composite,P.euphratica–nylon net–C.esculentus composite,Tamarix chinensis(T.chinensis),and T.chinensis–C.esculentus composite—using wind tunnel experiments and field observations.Sediment flux was measured at a normalized downwind distance(x/h)of 5,where x refers to the distance from the front edge(upwind side)of the shelterbelt for upwind measurements,and the distance from the rear edge(downwind side)for downwind measurements,and h represents the canopy height.Wind velocity was measured at x/h of–2,–1,1,2,3,5,and 7,and sand flux was measured at x/h=5,under initial wind velocities of 8.0 and 12.0 m/s.The results indicated that the P.euphratica–nylon net–C.esculentus composite was the most effective in reducing wind velocity,followed by the P.euphratica–C.esculentus composite.In contrast,the P.euphratica and T.chinensis exhibited relatively weaker wind reduction capabilities.Regarding sand flux,under moderate wind velocity(8.0 m/s),both the P.euphratica–C.esculentus composite and P.euphratica–nylon net–C.esculentus composite demonstrated the lowest sand flux values.However,under high wind velocity(12.0 m/s),the P.euphratica–nylon net–C.esculentus composite significantly outperformed the other shelterbelt models in sand retention,highlighting its superior windbreak and sand fixation efficacy.Field observations further validated the windbreak and sand fixation effects of C.esculentus.Comparisons between the bare sand plot and C.esculentus plot within protective forests demonstrated that planting C.esculentus can provide substantial ecological benefits in windbreak and sand-fixation.These findings,reinforced by field observations,strengthen the wind tunnel experiment results and highlight the critical role of C.esculentus in enhancing the performance of composite shelterbelts for desert ecological restoration.
