Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subniva...Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental stress.However,results indicate that some divergence in biomass allocation exists among organs.With increasing altitude,the mean fractions of total biomass allocated to aboveground parts decreased.The mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost constant.At 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,respectively.Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite trends.For all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher altitudes.Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained stable.It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots.In contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots.展开更多
Wastewater contains high concentration of nutrients,like nitrogen and phosphorus,which have been identified as the main reasons for water eutrophication and serious ecological issues.Therefore,cultivating a tolerant a...Wastewater contains high concentration of nutrients,like nitrogen and phosphorus,which have been identified as the main reasons for water eutrophication and serious ecological issues.Therefore,cultivating a tolerant and adaptive microalgae strain in wastewater is considered as a promising approach for sustainable biomass/lipid production.The potential usages of Desmodesmus sp.for biomass and lipid production within different artificial wastewater(AW)were investigated and the removal efficiencies of nutrient were compared.The maximum removal rate of chemical oxygen demand,ammonia nitrogen,nitrate nitrogen and phosphate were 272 mg/(L·d),14.021 mg/(L·d),7.774 mg/(L·d)and 3.347 mg/(L·d),respectively in AW2,AW3,AW5 and AW2.Maximum biomass(1.159 g/L)and lipid(280 mg/L)productions were observed in AW5,while the highest lipid content achieved was 37.42%in AW1.Fatty acid analysis showed that lipids extracted from AW-cultivated Desmodesmus sp.contained 59.57%-77.79%polyunsaturated fatty acids(30.6%-44.47%was linoleic acid).展开更多
基金supported by the National Science & Technology Pillar Program (Grant Nos. 2007BAD80B03 and 2007BAC06B01)a West Light Joint Scholar-ship from the Chinese Academy of Sciences in 2008the National Natural Science Foundation of China (Grant Nos. 40771074 and 30700080)
文摘Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental stress.However,results indicate that some divergence in biomass allocation exists among organs.With increasing altitude,the mean fractions of total biomass allocated to aboveground parts decreased.The mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost constant.At 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,respectively.Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite trends.For all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher altitudes.Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained stable.It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots.In contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots.
基金the National Key Technology R&D Program of China(Grant No.2012BAD47B03).
文摘Wastewater contains high concentration of nutrients,like nitrogen and phosphorus,which have been identified as the main reasons for water eutrophication and serious ecological issues.Therefore,cultivating a tolerant and adaptive microalgae strain in wastewater is considered as a promising approach for sustainable biomass/lipid production.The potential usages of Desmodesmus sp.for biomass and lipid production within different artificial wastewater(AW)were investigated and the removal efficiencies of nutrient were compared.The maximum removal rate of chemical oxygen demand,ammonia nitrogen,nitrate nitrogen and phosphate were 272 mg/(L·d),14.021 mg/(L·d),7.774 mg/(L·d)and 3.347 mg/(L·d),respectively in AW2,AW3,AW5 and AW2.Maximum biomass(1.159 g/L)and lipid(280 mg/L)productions were observed in AW5,while the highest lipid content achieved was 37.42%in AW1.Fatty acid analysis showed that lipids extracted from AW-cultivated Desmodesmus sp.contained 59.57%-77.79%polyunsaturated fatty acids(30.6%-44.47%was linoleic acid).
