Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to furthe...Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.展开更多
Soil moisture and its spatial pattern are important for understanding various hydrological,pedological,ecological and agricultural processes.In this study,data of rainfall and soil moisture contents at different depth...Soil moisture and its spatial pattern are important for understanding various hydrological,pedological,ecological and agricultural processes.In this study,data of rainfall and soil moisture contents at different depths(10 cm,20 cm,40 cm and 60 cm) in forestland and vegetable plot in the Taihu Lake Basin,China were monitored and analyzed for characteristics of soil moisture variation and its response to several typical rainfall events.The following results were observed.First,great temporal variation of soil moisture was observed in the surface layer than in deeper layer in vegetable plot.In contrast,in forestland,soil moisture had similar variation pattern at different depths.Second,initial soil moisture was an important factor influencing the vertical movement of soil water during rainfall events.In vegetable plot,simultaneous response of soil moisture to rainfall was observed at 10-and 20-cm depths due to fast infiltration when initial soil was relatively dry.However,traditional downward response order occurred when initial soil was relatively wet.Third,critical soil horizon interface was an active zone of soil water accumulation and lateral movement.A less permeable W-B soil horizon interface(40-cm depth) in vegetable plot can create perched water table above it and elevate the soil water content at the corresponding depth.Fourth,the land cover was an effective control factor of soil moisture during small and moderate rainfall events.In the forestland,moderate and small rainfall events had tiny influences on soil moisture due to canopy and surface O horizon interception.Fifth,preferential flow and lateral subsurface interflow were important paths of soil water movement.During large and long duration rainfall events,lateral subsurface flow and preferential flow through surface crack or soil pipe occurred,which recharged the deep soil.However,in more concentrated large storm,surface crack or soil pipe connected by soil macropores was the main contributor to the occurrence of preferential flow.Findings of this study provide a theoretical foundation for sustainable water and fertilizer management and land use planning in the Taihu Lake Basin.展开更多
A. chilensis （Elaeocarpaceae） is commonly known as maqui, a species widely distributed in Chile. The plant participates in the structure of the Chilean temperate rainforest, currently being found mainly as fragmente...A. chilensis （Elaeocarpaceae） is commonly known as maqui, a species widely distributed in Chile. The plant participates in the structure of the Chilean temperate rainforest, currently being found mainly as fragmented forest. Maqui has been listed as the plant with the highest content of phenols when compared with other berries. Multiplication by both, seeds and vegetative has been obtained, opening the possibility to cultivate the plant. Leaves ofmaqui have been traditionally used in the native herbal medicine to treat diverse ailments. Studies indicate the presence of indolic alkaloids, flavonoids, cyaniding glucosides, delfidine, malvidine, petunidine, cumarines and triterpenes. Recent studies support therapeutic properties of maqui leaves, concluding that extracts obtained with polar solvents showed stabilizing capacity of free radicals and antioxidant capacity of plasma in humans. Other works show that fruits could be useful as antioxidant and cardioprotective source. The high contents of anthocyanins and polyglycosylated derivatives make berries of maqui an interesting p｜ant for food and pharmaceutical uses. A. chilensis polyphenols molecular mechanism of action and toxicity can be attributed to functional perturbation of cell membrane lipid bilayers. This review summarizes the research up to date, from propagation methods to chemical properties, indicating weak and lacking aspects.展开更多
文摘Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.
基金Under the auspices of National Natural Science Foundation of China(No.41271109,41030745)Key '135' Project of Chinese Academy of Sciences(No.NIGLAS2012135005)China Postdoctoral Science Foundation(No.2013M540470)
文摘Soil moisture and its spatial pattern are important for understanding various hydrological,pedological,ecological and agricultural processes.In this study,data of rainfall and soil moisture contents at different depths(10 cm,20 cm,40 cm and 60 cm) in forestland and vegetable plot in the Taihu Lake Basin,China were monitored and analyzed for characteristics of soil moisture variation and its response to several typical rainfall events.The following results were observed.First,great temporal variation of soil moisture was observed in the surface layer than in deeper layer in vegetable plot.In contrast,in forestland,soil moisture had similar variation pattern at different depths.Second,initial soil moisture was an important factor influencing the vertical movement of soil water during rainfall events.In vegetable plot,simultaneous response of soil moisture to rainfall was observed at 10-and 20-cm depths due to fast infiltration when initial soil was relatively dry.However,traditional downward response order occurred when initial soil was relatively wet.Third,critical soil horizon interface was an active zone of soil water accumulation and lateral movement.A less permeable W-B soil horizon interface(40-cm depth) in vegetable plot can create perched water table above it and elevate the soil water content at the corresponding depth.Fourth,the land cover was an effective control factor of soil moisture during small and moderate rainfall events.In the forestland,moderate and small rainfall events had tiny influences on soil moisture due to canopy and surface O horizon interception.Fifth,preferential flow and lateral subsurface interflow were important paths of soil water movement.During large and long duration rainfall events,lateral subsurface flow and preferential flow through surface crack or soil pipe occurred,which recharged the deep soil.However,in more concentrated large storm,surface crack or soil pipe connected by soil macropores was the main contributor to the occurrence of preferential flow.Findings of this study provide a theoretical foundation for sustainable water and fertilizer management and land use planning in the Taihu Lake Basin.
文摘A. chilensis （Elaeocarpaceae） is commonly known as maqui, a species widely distributed in Chile. The plant participates in the structure of the Chilean temperate rainforest, currently being found mainly as fragmented forest. Maqui has been listed as the plant with the highest content of phenols when compared with other berries. Multiplication by both, seeds and vegetative has been obtained, opening the possibility to cultivate the plant. Leaves ofmaqui have been traditionally used in the native herbal medicine to treat diverse ailments. Studies indicate the presence of indolic alkaloids, flavonoids, cyaniding glucosides, delfidine, malvidine, petunidine, cumarines and triterpenes. Recent studies support therapeutic properties of maqui leaves, concluding that extracts obtained with polar solvents showed stabilizing capacity of free radicals and antioxidant capacity of plasma in humans. Other works show that fruits could be useful as antioxidant and cardioprotective source. The high contents of anthocyanins and polyglycosylated derivatives make berries of maqui an interesting p｜ant for food and pharmaceutical uses. A. chilensis polyphenols molecular mechanism of action and toxicity can be attributed to functional perturbation of cell membrane lipid bilayers. This review summarizes the research up to date, from propagation methods to chemical properties, indicating weak and lacking aspects.
