Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly we...Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes.展开更多
Through one hundred years of adaptation in China, The Acer negundo Linn. (as hlea f maple), originally grown in North America, has developed morphological charact er istics to cope the severe situation of its habitats...Through one hundred years of adaptation in China, The Acer negundo Linn. (as hlea f maple), originally grown in North America, has developed morphological charact er istics to cope the severe situation of its habitats. Two ecotypes from different vegetation belts in the ecotone of eastern Inner Mongolia Autonomous Region wer e detected. Although there was no macroscopic difference, contrasting micro-ch a racteristics had been observed between the two sources. The leaves from more dro ught and warmer zone were found with more trichomes, more and smaller stomata, l arger subsidiary cells, thicker palisade and flatter epidermal wax than those of leaves from the more humid and colder zone. Microstructures of the leaves from xeric sources can more effectively reduce leaf temperature and conserving water than those of mesic sources. Intra-species difference of the two ecotypes is th e result of adaptation in different environments. This should be considered when characteristics of foliage are used as characters of species in taxonomy.展开更多
基金founded by Major Project of Chinese National Programs for Fundamental Research and Development (Grant No.2007CB416603)
文摘Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes.
文摘Through one hundred years of adaptation in China, The Acer negundo Linn. (as hlea f maple), originally grown in North America, has developed morphological charact er istics to cope the severe situation of its habitats. Two ecotypes from different vegetation belts in the ecotone of eastern Inner Mongolia Autonomous Region wer e detected. Although there was no macroscopic difference, contrasting micro-ch a racteristics had been observed between the two sources. The leaves from more dro ught and warmer zone were found with more trichomes, more and smaller stomata, l arger subsidiary cells, thicker palisade and flatter epidermal wax than those of leaves from the more humid and colder zone. Microstructures of the leaves from xeric sources can more effectively reduce leaf temperature and conserving water than those of mesic sources. Intra-species difference of the two ecotypes is th e result of adaptation in different environments. This should be considered when characteristics of foliage are used as characters of species in taxonomy.
