In sandy forest with a forest canopy gap for a period of over 30 years, the spruce（Picea mongolica） seedlings were monitored on two 5-m- wide transects from the center of a large gap into the surrounding forest. The...In sandy forest with a forest canopy gap for a period of over 30 years, the spruce（Picea mongolica） seedlings were monitored on two 5-m- wide transects from the center of a large gap into the surrounding forest. The farther they were to the far center, the taller grew the seedling and the more is the number of seedling. There were many seedlings under the canopy but almost all seedlings died before they grow up. Along the forest edge, growth of seedlings was temporarily enhanced by lateral penetration of light from the gap. The implications for natural forest regeneration dynamics are discussed. Our results prove that in P mongolica forest a gap disturbance creates a non-uniform environment for regeneration of the species, and determines that the forest was a non-even aged forest.展开更多
Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials （...Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials （cow-dung, poultry droppings, cocoa and kola pod husks） compared to NPK and control （no fertilizer） treatments was conducted on the growth performance of cashew seedlings at Ibadan, Nigeria. The fertilizers were applied to supply 15 g N seedlingl in 3 replications. Cashew seedling growth parameters and dry matter yield were determined. Fertilizers resulted to consistently general higher plant height, girth, number of leaves and leaf area compared to NPK and control. The differences in the mean values were however not significantly different for girth but it was significant （P 〈 0.5） for plant height, number of leaves and leaf area, while there was no particular regular trend for plant number of branches. Plant root lengths were significantly higher using the organic fertilizers than NPK and control. Similar trend was obtained in the dry weight values for plant leaf, stem, root and total dry matter yield. There was however no consistent significant effect on NPK usage over control for all the parameters. It was therefore deduced that optimal growth performance and better establishment of cashew seedlings could be obtained with the use of organic fertilizers rather than inorganic fertilizer. The use of cocoa pod husk followed by cow-dung and poultry droppings were outstanding in better growth and dry matter yield performance of cashew seedlings and were advised for this purpose.展开更多
基金Foundation project： The National Natural Science Foundation of China （No. 39900019, 30070129）
文摘In sandy forest with a forest canopy gap for a period of over 30 years, the spruce（Picea mongolica） seedlings were monitored on two 5-m- wide transects from the center of a large gap into the surrounding forest. The farther they were to the far center, the taller grew the seedling and the more is the number of seedling. There were many seedlings under the canopy but almost all seedlings died before they grow up. Along the forest edge, growth of seedlings was temporarily enhanced by lateral penetration of light from the gap. The implications for natural forest regeneration dynamics are discussed. Our results prove that in P mongolica forest a gap disturbance creates a non-uniform environment for regeneration of the species, and determines that the forest was a non-even aged forest.
文摘Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials （cow-dung, poultry droppings, cocoa and kola pod husks） compared to NPK and control （no fertilizer） treatments was conducted on the growth performance of cashew seedlings at Ibadan, Nigeria. The fertilizers were applied to supply 15 g N seedlingl in 3 replications. Cashew seedling growth parameters and dry matter yield were determined. Fertilizers resulted to consistently general higher plant height, girth, number of leaves and leaf area compared to NPK and control. The differences in the mean values were however not significantly different for girth but it was significant （P 〈 0.5） for plant height, number of leaves and leaf area, while there was no particular regular trend for plant number of branches. Plant root lengths were significantly higher using the organic fertilizers than NPK and control. Similar trend was obtained in the dry weight values for plant leaf, stem, root and total dry matter yield. There was however no consistent significant effect on NPK usage over control for all the parameters. It was therefore deduced that optimal growth performance and better establishment of cashew seedlings could be obtained with the use of organic fertilizers rather than inorganic fertilizer. The use of cocoa pod husk followed by cow-dung and poultry droppings were outstanding in better growth and dry matter yield performance of cashew seedlings and were advised for this purpose.
