Background： The global search for new ways to sequester carbon has already reached agricultural lands. Such land constitutes a major potential carbon sink. The production of high value timber within agroforestry syst...Background： The global search for new ways to sequester carbon has already reached agricultural lands. Such land constitutes a major potential carbon sink. The production of high value timber within agroforestry systems can facilitate an in-situ carbon storage function. This is followed by a potential long term ex- situ carbon sinkwithin long lasting products such as veneer and furniture. For this purpose wild cherry （Prunus avium L.） is an interesting option for middle Europe, yielding high prices on the timber market. Methods： A total number of 39 wild cherry were sampled in 2012 and 2013 to assess the leafless above ground biomass. The complete trees including stem and branches were separated into 1 cm diameter classes. Wood and bark from sub-samples were analysed separately and nutrient content was derived. Models for biomass estimation were constructed for all tree compartments. Results： The smallest diameter classes possess the highest proportion of bark due to smaller cross sectional area. Tree boles with a greater amount of stem wood above 10 cm in diameter will have a more constant bark proportion. Total branch bark proportion also remains relatively constant above dl.Bm measurements of 8 cm. A balance is evident between the production of new branches with a low diameter and high bark proportion offset by the thickening and a relative reduction in bark proportion in larger branches. The results show that a single tree with an age of 17 and 18 years can store up to 85 kg of carbon within the aboveground biomass portion, an amount that will increase as the tree matures. Branches display greater nutrient content than stem sections per volume unit which can be attributed to a greater bark proportion. Conclusions： Using the derived models the carbon and the nutrient content of above-ground woody biomass of whole trees can be calculated. Suggested values for carbon with other major and minor nutrients held within relatively immature trees strongly supports the idea of the inclusion of wild cherry within agroforestry systems as an option for carbon sequestration.展开更多
以呼和浩特市赛罕区典型乔木林为研究对象,分别在小钻杨(Populus×xiaozhuanica)和旱柳(Salix matsudana)纯林内设置样地,调查小钻杨和旱柳的生长状况、不同器官的生物量,及林下草本植被的生物量,并测定不同器官的碳含量,以期为研...以呼和浩特市赛罕区典型乔木林为研究对象,分别在小钻杨(Populus×xiaozhuanica)和旱柳(Salix matsudana)纯林内设置样地,调查小钻杨和旱柳的生长状况、不同器官的生物量,及林下草本植被的生物量,并测定不同器官的碳含量,以期为研究区典型乔木林碳储量计算和评价提供参考。结果表明,小钻杨和旱柳的不同器官生物量变化趋势相同,均表现为干>根>枝>叶,小钻杨单株平均生物量为(29.66±2.14)kg,旱柳单株平均生物量为(16.68±1.36)kg。小钻杨林下草本层平均生物量为(14.45±1.58)g.m^(-2),旱柳林下草本层平均生物量为(15.89±2.36)g.m^(-2)。小钻杨各器官碳含量在45%~52%,旱柳各器官碳含量为44%~53%。赛罕区2011年营造的23.5 hm^(2)乔木林可产生的温室气体减排量约为999.99 t CO_(2)当量,其中小钻杨林为602.01 t CO_(2)当量,旱柳林为397.98 t CO_(2)当量。展开更多
Based on the data of the Jiaozhou Bay Ecosystem Dynamic Research, cell volume and sur face area of 87 common phytoplankton species in China sea waters were calculated with assignment of the similar geometric form. The...Based on the data of the Jiaozhou Bay Ecosystem Dynamic Research, cell volume and sur face area of 87 common phytoplankton species in China sea waters were calculated with assignment of the similar geometric form. The cell plasma volume, live weight, Carbon content and nitrogen content were also calculated with the methods of Mullin et al. (1966), Strathmann (1967), Eppley et al. (1970), and Taguchi (1976). After comparing these methods, we chase the method of Eppley et al. (1970) as the hot method for calculating phytoplankton carbon content in China sea waters.展开更多
Although afforestation of farmlands has been proposed as an effective method of carbon(C) sequestration, there remain uncertainties that deter us from developing a clear picture of C stocks in plantation ecosystems.Th...Although afforestation of farmlands has been proposed as an effective method of carbon(C) sequestration, there remain uncertainties that deter us from developing a clear picture of C stocks in plantation ecosystems.This study investigated the dynamics of stand structure and plant diversity, and C and nitrogen(N) pools in trees,herbs, litter, and soil(0–100 cm depth) in black locust plantations aged 9, 17, 30, and 37 years, and in newly abandoned farmlands as pre-afforestation sites, on the Loess Plateau, China. Stand density decreased significantly, while tree diameter at breast height and height increased during stand development. The dominant species of the herb layer differed with age. Afforestation resulted in slight increases in tree C and N storage in plantations from 9 to 30 years of age, and then significantly increased from 30 to 37 years. Compared to pre-afforestation, C and N storage in soil decreased to minimum values in stands aged 17 and 9 years, respectively. The soil re-accumulated C and N during stand development, attaining equilibrium levels similar to those in pre-afforestation when stands reached about 30 years of age. Soil C and N storage in 37-year stands were 29 and 16% higher, respectively, than in pre-afforestation levels. However, C and N concentrations in the subsoil(20–40 cm) were still less than the preafforestation levels for stands of all ages(from 9 to 37 years). The relative contribution to the total ecosystem C and N pools increased in trees and decreased in soil during the observed period. Our results indicate that afforestation reduced soil C and N storage during the early stages of stand development. We conclude that the growing phase of an afforested stand over its initial 30 years is important for C and N sequestration by black locust due to the C and N storage that result from recovered soil quality and an increase in tree biomass.展开更多
Heilongjiang province is the largest forest zone in China and the forest coverage rate is 46%. Forests of Heilongjiang province play an important role in the forest ecosystem of China. In this study we investi- gated ...Heilongjiang province is the largest forest zone in China and the forest coverage rate is 46%. Forests of Heilongjiang province play an important role in the forest ecosystem of China. In this study we investi- gated the spatial distribution of forest carbon storage in Heilongjiang province using 3083 plots sampled in 2010. We attempted to fit two global models, ordinary least squares model （OLS）, linear mixed model （LMM）, and a local model, geographically weighted regression model （GWR）, to the relationship between forest carbon content and stand, environment, and climate factors. Five predictors significantly affected forest carbon storage and spatial distribution, viz. average diameter of stand （DBH）, number of trees per hectare （TPH）, elevation （Elev）, slope （Slope） and the product of precipitation and temperature （Rain Temp）. The GWR model outperformed the two global models in both model fitting and prediction because it successfully reduced both spatial auto- correlation and heterogeneity in model residuals. More importantly, the GWR model provided localized model coefficients for each location in the study area, which allowed us to evaluate the influences of local stand conditions and topographic features on tree and stand growth, and forest carbon stock. It also helped us to better understand the impacts of silvi- cultural and management activities on the amount and changes of forest carbon storage across the province. The detailed information can be readily incorporated with the mapping ability of GIS software to provide excellent tools for assessing the distribution and dynamics of the for- est-carbon stock in the next few years.展开更多
【目的】研究秸秆配施化肥对暗棕壤团聚体组成、团聚体碳氮含量、土壤微生物量特征及小麦产量的影响,揭示长期秸秆配施化肥下土壤肥力和生产力的协同提升机制。【方法】依托长期定位40年施肥试验,选取4个处理:单施化肥(NP)、秸秆配施化...【目的】研究秸秆配施化肥对暗棕壤团聚体组成、团聚体碳氮含量、土壤微生物量特征及小麦产量的影响,揭示长期秸秆配施化肥下土壤肥力和生产力的协同提升机制。【方法】依托长期定位40年施肥试验,选取4个处理:单施化肥(NP)、秸秆配施化肥(S+NP)、秸秆配施1/2化肥(S+1/2NP)、秸秆配施1/4化肥(S+1/4NP),其中秸秆为麦秸隔年还田,用量为3000 kg·hm^(-2),氮磷化肥用量为150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)。采集0—20 cm土层土样,利用湿筛法得到不同粒级的水稳性团聚体,测定团聚体中有机碳(SOC)、氮含量及土壤微生物量碳(SMBC)、微生物量氮(SMBN)含量。【结果】(1)长期秸秆配施化肥显著降低土壤容重并提高了团聚体稳定性,和NP相比,S+NP处理土壤容重降低4.7%,>2 mm团聚体含量、平均重量直径(MWD)和几何重量直径(GWD)分别提升254.4%、76.5%和91.3%。(2)S+NP、S+1/2NP处理>2 mm团聚体百分含量、MWD和GWD显著高于S+1/4NP,分别增加了49.1%—52.4%,19.43%—22.4%和24.2%—33.3%。(3)S+NP、S+1/2NP、S+1/4NP和NP相比增加了>2 mm和>0.25 mm团聚体对土壤有机碳、全氮贡献率,并显著提高全土SOC、SMBC和SMBN含量;其中,SOC含量在S+NP中最高,比S+1/2NP、S+1/4NP高6.3%和12.6%。(4)产量表现为S+NP>NP>S+1/2NP>S+1/4NP处理,S+NP比减施化肥处理提高小麦产量28.6%—47.5%。(5)土壤团聚体稳定性、SOC含量及小麦产量之间有较好的相关性,>2 mm和>0.25 mm团聚体含量、MWD和GWD分别与全土SOC含量及小麦产量呈显著或极显著正相关。【结论】暗棕壤地区在长期秸秆还田条件下,配施化肥量150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)时能提高土壤团聚体稳定性、有机碳含量、微生物生物量和小麦产量,最大化实现土壤结构改良、肥力提升和作物增产的协同效应。展开更多
基金supported by the EU FP7 project StarTree(Grant Agreement Number 311919)the Federal Ministry of Education and Research(BMBF) within the AGROCOP project (support code 033L051B)the German Federal Ministry of Food and Agriculture(BMEL) within the project Agro-Wertholz(support code 22031112)
文摘Background： The global search for new ways to sequester carbon has already reached agricultural lands. Such land constitutes a major potential carbon sink. The production of high value timber within agroforestry systems can facilitate an in-situ carbon storage function. This is followed by a potential long term ex- situ carbon sinkwithin long lasting products such as veneer and furniture. For this purpose wild cherry （Prunus avium L.） is an interesting option for middle Europe, yielding high prices on the timber market. Methods： A total number of 39 wild cherry were sampled in 2012 and 2013 to assess the leafless above ground biomass. The complete trees including stem and branches were separated into 1 cm diameter classes. Wood and bark from sub-samples were analysed separately and nutrient content was derived. Models for biomass estimation were constructed for all tree compartments. Results： The smallest diameter classes possess the highest proportion of bark due to smaller cross sectional area. Tree boles with a greater amount of stem wood above 10 cm in diameter will have a more constant bark proportion. Total branch bark proportion also remains relatively constant above dl.Bm measurements of 8 cm. A balance is evident between the production of new branches with a low diameter and high bark proportion offset by the thickening and a relative reduction in bark proportion in larger branches. The results show that a single tree with an age of 17 and 18 years can store up to 85 kg of carbon within the aboveground biomass portion, an amount that will increase as the tree matures. Branches display greater nutrient content than stem sections per volume unit which can be attributed to a greater bark proportion. Conclusions： Using the derived models the carbon and the nutrient content of above-ground woody biomass of whole trees can be calculated. Suggested values for carbon with other major and minor nutrients held within relatively immature trees strongly supports the idea of the inclusion of wild cherry within agroforestry systems as an option for carbon sequestration.
文摘以呼和浩特市赛罕区典型乔木林为研究对象,分别在小钻杨(Populus×xiaozhuanica)和旱柳(Salix matsudana)纯林内设置样地,调查小钻杨和旱柳的生长状况、不同器官的生物量,及林下草本植被的生物量,并测定不同器官的碳含量,以期为研究区典型乔木林碳储量计算和评价提供参考。结果表明,小钻杨和旱柳的不同器官生物量变化趋势相同,均表现为干>根>枝>叶,小钻杨单株平均生物量为(29.66±2.14)kg,旱柳单株平均生物量为(16.68±1.36)kg。小钻杨林下草本层平均生物量为(14.45±1.58)g.m^(-2),旱柳林下草本层平均生物量为(15.89±2.36)g.m^(-2)。小钻杨各器官碳含量在45%~52%,旱柳各器官碳含量为44%~53%。赛罕区2011年营造的23.5 hm^(2)乔木林可产生的温室气体减排量约为999.99 t CO_(2)当量,其中小钻杨林为602.01 t CO_(2)当量,旱柳林为397.98 t CO_(2)当量。
文摘Based on the data of the Jiaozhou Bay Ecosystem Dynamic Research, cell volume and sur face area of 87 common phytoplankton species in China sea waters were calculated with assignment of the similar geometric form. The cell plasma volume, live weight, Carbon content and nitrogen content were also calculated with the methods of Mullin et al. (1966), Strathmann (1967), Eppley et al. (1970), and Taguchi (1976). After comparing these methods, we chase the method of Eppley et al. (1970) as the hot method for calculating phytoplankton carbon content in China sea waters.
基金supported by the National Nature Science Foundation of China(Nos.41201088,41371506 and 41601058)
文摘Although afforestation of farmlands has been proposed as an effective method of carbon(C) sequestration, there remain uncertainties that deter us from developing a clear picture of C stocks in plantation ecosystems.This study investigated the dynamics of stand structure and plant diversity, and C and nitrogen(N) pools in trees,herbs, litter, and soil(0–100 cm depth) in black locust plantations aged 9, 17, 30, and 37 years, and in newly abandoned farmlands as pre-afforestation sites, on the Loess Plateau, China. Stand density decreased significantly, while tree diameter at breast height and height increased during stand development. The dominant species of the herb layer differed with age. Afforestation resulted in slight increases in tree C and N storage in plantations from 9 to 30 years of age, and then significantly increased from 30 to 37 years. Compared to pre-afforestation, C and N storage in soil decreased to minimum values in stands aged 17 and 9 years, respectively. The soil re-accumulated C and N during stand development, attaining equilibrium levels similar to those in pre-afforestation when stands reached about 30 years of age. Soil C and N storage in 37-year stands were 29 and 16% higher, respectively, than in pre-afforestation levels. However, C and N concentrations in the subsoil(20–40 cm) were still less than the preafforestation levels for stands of all ages(from 9 to 37 years). The relative contribution to the total ecosystem C and N pools increased in trees and decreased in soil during the observed period. Our results indicate that afforestation reduced soil C and N storage during the early stages of stand development. We conclude that the growing phase of an afforested stand over its initial 30 years is important for C and N sequestration by black locust due to the C and N storage that result from recovered soil quality and an increase in tree biomass.
基金financially supported by the Scientific Research Funds for Forestry Public Welfare of China(Granted No.201004026)the Program for Changjiang Scholars and Innovative Research Team in University(IRT1054)
文摘Heilongjiang province is the largest forest zone in China and the forest coverage rate is 46%. Forests of Heilongjiang province play an important role in the forest ecosystem of China. In this study we investi- gated the spatial distribution of forest carbon storage in Heilongjiang province using 3083 plots sampled in 2010. We attempted to fit two global models, ordinary least squares model （OLS）, linear mixed model （LMM）, and a local model, geographically weighted regression model （GWR）, to the relationship between forest carbon content and stand, environment, and climate factors. Five predictors significantly affected forest carbon storage and spatial distribution, viz. average diameter of stand （DBH）, number of trees per hectare （TPH）, elevation （Elev）, slope （Slope） and the product of precipitation and temperature （Rain Temp）. The GWR model outperformed the two global models in both model fitting and prediction because it successfully reduced both spatial auto- correlation and heterogeneity in model residuals. More importantly, the GWR model provided localized model coefficients for each location in the study area, which allowed us to evaluate the influences of local stand conditions and topographic features on tree and stand growth, and forest carbon stock. It also helped us to better understand the impacts of silvi- cultural and management activities on the amount and changes of forest carbon storage across the province. The detailed information can be readily incorporated with the mapping ability of GIS software to provide excellent tools for assessing the distribution and dynamics of the for- est-carbon stock in the next few years.
文摘【目的】研究秸秆配施化肥对暗棕壤团聚体组成、团聚体碳氮含量、土壤微生物量特征及小麦产量的影响,揭示长期秸秆配施化肥下土壤肥力和生产力的协同提升机制。【方法】依托长期定位40年施肥试验,选取4个处理:单施化肥(NP)、秸秆配施化肥(S+NP)、秸秆配施1/2化肥(S+1/2NP)、秸秆配施1/4化肥(S+1/4NP),其中秸秆为麦秸隔年还田,用量为3000 kg·hm^(-2),氮磷化肥用量为150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)。采集0—20 cm土层土样,利用湿筛法得到不同粒级的水稳性团聚体,测定团聚体中有机碳(SOC)、氮含量及土壤微生物量碳(SMBC)、微生物量氮(SMBN)含量。【结果】(1)长期秸秆配施化肥显著降低土壤容重并提高了团聚体稳定性,和NP相比,S+NP处理土壤容重降低4.7%,>2 mm团聚体含量、平均重量直径(MWD)和几何重量直径(GWD)分别提升254.4%、76.5%和91.3%。(2)S+NP、S+1/2NP处理>2 mm团聚体百分含量、MWD和GWD显著高于S+1/4NP,分别增加了49.1%—52.4%,19.43%—22.4%和24.2%—33.3%。(3)S+NP、S+1/2NP、S+1/4NP和NP相比增加了>2 mm和>0.25 mm团聚体对土壤有机碳、全氮贡献率,并显著提高全土SOC、SMBC和SMBN含量;其中,SOC含量在S+NP中最高,比S+1/2NP、S+1/4NP高6.3%和12.6%。(4)产量表现为S+NP>NP>S+1/2NP>S+1/4NP处理,S+NP比减施化肥处理提高小麦产量28.6%—47.5%。(5)土壤团聚体稳定性、SOC含量及小麦产量之间有较好的相关性,>2 mm和>0.25 mm团聚体含量、MWD和GWD分别与全土SOC含量及小麦产量呈显著或极显著正相关。【结论】暗棕壤地区在长期秸秆还田条件下,配施化肥量150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)时能提高土壤团聚体稳定性、有机碳含量、微生物生物量和小麦产量,最大化实现土壤结构改良、肥力提升和作物增产的协同效应。
