Decreasing the forest ecosystem leaf-area index error(LAIe)helps accurately estimate the growth and light energy utilization of aboveground foliage.Analyzing light transmission in forest ecosystems can effectively det...Decreasing the forest ecosystem leaf-area index error(LAIe)helps accurately estimate the growth and light energy utilization of aboveground foliage.Analyzing light transmission in forest ecosystems can effectively determine LAIe.The LAI-2200 plant canopy analyzer(PCA)is used extensively for rapid field-effective LAI(LAIe)measurements and primarily to measure forest canopy LAIe values.However,sometimes this parameter must also be measured in forests with small clearings.In this study,we used the LAI-2200 PCA to obtain one A-value and four B-values each for the canopy,herbaceous layer,and forest ecosystem LAIe.Field measurements showed that the three LAIe types were obviously different.In certain quadrats,the average herbaceous layer(Dicranopteris dichotoma Bernh.)LAIe apparently exceeded that of the Pinus massoniana forest ecosystem.The sources of this error were measuring and recording A-value readings for small canopies and underestimating the ecosystem LAIe.We obtained similar coefficients of determination for both the pre-recomputation and post-recomputation of the canopy and forest ecosystem LAIe(R^2C 0.96 and R^2C 0.99,respectively);thus,the error was decreased.Measuring field LAIe with the LAI-2200 PCA and recomputation should compensate for LAIe underestimation in complex forest ecosystems.展开更多
In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Ma...In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Malian daylily. According to the results, late-maturing daylily eultivar Jinlei No. 1 exhibited good agro- nomic traits and strong resistance, The first day of harvest of Jinlei No. 1 was more than 10 d later compared with Malian daylily and Xian daylily ; harvest duration of Jinlei No. 1 was 4 d longer than Malian daylily and 5 d than Xian daylily; the yield of Jinlei No. 1 was improved by 3.41% and 5.16% compared with Malian daylily and Xian daylily, respectively. The cultivation of late-maturing daylily cuhivar Jinlei No. 1 can effectively avoid heavy economic losses caused by overlap period of early harvest of daylily and critical busy summer farming in Qingyang City.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41401385 and 31770760)the Foundation of College of Forestry,Fujian Agricultural and Forest University(Grant No.61201400833)
文摘Decreasing the forest ecosystem leaf-area index error(LAIe)helps accurately estimate the growth and light energy utilization of aboveground foliage.Analyzing light transmission in forest ecosystems can effectively determine LAIe.The LAI-2200 plant canopy analyzer(PCA)is used extensively for rapid field-effective LAI(LAIe)measurements and primarily to measure forest canopy LAIe values.However,sometimes this parameter must also be measured in forests with small clearings.In this study,we used the LAI-2200 PCA to obtain one A-value and four B-values each for the canopy,herbaceous layer,and forest ecosystem LAIe.Field measurements showed that the three LAIe types were obviously different.In certain quadrats,the average herbaceous layer(Dicranopteris dichotoma Bernh.)LAIe apparently exceeded that of the Pinus massoniana forest ecosystem.The sources of this error were measuring and recording A-value readings for small canopies and underestimating the ecosystem LAIe.We obtained similar coefficients of determination for both the pre-recomputation and post-recomputation of the canopy and forest ecosystem LAIe(R^2C 0.96 and R^2C 0.99,respectively);thus,the error was decreased.Measuring field LAIe with the LAI-2200 PCA and recomputation should compensate for LAIe underestimation in complex forest ecosystems.
基金Supported by National Spark Project of China(2012GA860011)Spark Project of Gansu Provincial Science and Technology Department(S2012G100009)
文摘In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Malian daylily. According to the results, late-maturing daylily eultivar Jinlei No. 1 exhibited good agro- nomic traits and strong resistance, The first day of harvest of Jinlei No. 1 was more than 10 d later compared with Malian daylily and Xian daylily ; harvest duration of Jinlei No. 1 was 4 d longer than Malian daylily and 5 d than Xian daylily; the yield of Jinlei No. 1 was improved by 3.41% and 5.16% compared with Malian daylily and Xian daylily, respectively. The cultivation of late-maturing daylily cuhivar Jinlei No. 1 can effectively avoid heavy economic losses caused by overlap period of early harvest of daylily and critical busy summer farming in Qingyang City.
