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991.
992.
武夷山风景名胜区景观空间格局研究 总被引:24,自引:0,他引:24
景观结构又称景观空间格局 ,是大小和形状不一的景观嵌块体在景观空间上的排列 (伍业钢等 ,1992 )。景观结构决定着景观功能 ,而功能的改变最终将从结构的变化中反映出来 ,因此 ,景观空间格局研究是景观生态学三大核心问题的核心 (贾宝全等 ,2 0 0 1)。景观异质性是景观最重要的属性之一 (Formanetal .,1986 ;Risseretal.,1984 ;Turner,1987) ,而景观空间格局既是景观异质性的具体体现者 ,同时又是多种生态过程在不同尺度上作用的最终结果 (贾宝全等 ,2 0 0 1)。景观空间格局及其变化和发展是自然、生物和社会要素相互作用的结果 ,影响着… 相似文献
993.
油茶林生物量与养分生物循环的研究 总被引:12,自引:0,他引:12
对不同发育期油茶林生物量与养分的生物循环进行了研究。结果表明,从幼龄期至盛果期油茶林生物量逐步积累,盛果期生物量达到16.139t/hm2,其中经济生物量为1.798t/hm2;不同发育期油茶林分的生产力不同,盛果期油茶林太阳能利用率最高,为0.2%;不同发育期油茶林光合产物在各器官的分配比例不同;不同发育期油茶林系统大量元素(N、P、K、Ca、Mg)的吸收量、存留量、归还量及输出量不同。并提出了油茶林系统施肥的监界量。 相似文献
994.
995.
Bin He Wuming Qin Qingbiao Wu Jun Dai Yong Huang Feng Liu 《Frontiers of Forestry in China》2007,2(4):443-447
For this paper, we studied the water-holding capacity of canopy, vegetation layer under canopy and litter layer, the water-holding
capacity and permeability of soil as well as their changes with growth of stands in Acacia mangium plantations of three different age classes (four-, seven-and 11-year-old). Results show that total water-holding above ground
in the order of 11-year stand age (52.86 t/hm2)>seven-year stand age (41.90 t/hm2)>seven-year stand age (25.78 t/hm2), the increment tendency increased with stand age. Similar sequence also obtained on the water-holding capacity and permeation
capacity of soil (0–40 cm). The total water-storage capacity both above ground and soil in four-year-old, seven-year-old and
11-year-old of A. mangium plantations were 2,023.0, 2,158.4 and 2,260.4 t/hm2, respectively, and the all value of water conservation were 1,372.70, 1,474.42 and 1,549.91 yuan (RMB)/hm2, respectively. Therefore, A. mangium plantation had a good ability to modify soil structure and good water conservation function.
__________
Translated from Journal of Soil and Water Conservation, 2006, 20(5): 5–8, 27 [译自: 水土保持学报] 相似文献
996.
以安楚高速公路某一立交匝道测设数据为例 ,给出坐标计算公式及编程思路 ,节省了坐标计算的时间及提高了计算数据的精度 ,为立交匝道放样提供了方便 相似文献
997.
Post-fire habitat restoration of sables during winter season in northern slope of the Great Xing'an Mountains 总被引:1,自引:0,他引:1
XIE Fu-ju LI Xiu-zhen XIAO Du-ning Hong S. He 《林业研究》2006,17(3):231-237
Habitat loss and fragmentation have been associated with the decline of endangered species. In 1987, a catastrophic fire in the northern Great Hing'an Mountains of China, where the main habitat of sables (Martes zibellina) is located, aggravated the loss and fragmentation of the forest landscape. Due to restricted distribution and low population density, sables were listed in the national first-grade protected species in China. The objective of this paper was to identify to what extent the habitat of sables had been restored 13 years after the fire. Based on the behavioral data, which came from field survey information by radio-tracking, GPS (Global Positioning System) and forest inventory data, suitability habitat maps were derived using the Ecological Niche Suitability Model (ENSM). In addition, the habitat structure was analyzed with selected landscape indices. Although forest cover mostly had been restored by 2000, the results indicated that, compared to the pre-fire situation, the areas of suitable habitat had been reduced significantly, especially those of less suitable, marginally suitable and moderately suitable designation. Fragmentation was aggravated, and suitable patches were found to be further isolated with the exception of those in most suitable areas. The ratio of the patch perimeter to area in unsuitable, moderately suitable and suitable areas decreased, while the ratios within other suitability types increased. Moreover, the percentage of soft boundaries decreased slightly, which can influence the redistribution of sables. The results above indicated that the suitable habitat had deteriorated, and the restoration of the sables' habitat remained to be done. 相似文献
998.
Chunjie Tian Xingyuan He Yang Zhong Jiakuan Chen 《Forest Ecology and Management》2002,170(1-3):307-312
Through biological inoculation technology, the joint symbiosis of Tibetan seabuckthorn (Hippophae tibetana) in pure culture was identified and the effects of dual inoculation with Frankia and mycorrhizal fungi on the host plants in pot cultures were investigated. The results obtained from the comparative study showed that H. tibetana could form nodules and VA mycorrhiza both in pot and pure cultures. VA mycorrhizae and Frankia can stimulate the growth and the nitrogen fixation ability of host plants, respectively, yet the stimulation of the dual inoculation on the growth and nitrogen fixation ability of the host plants was more significant (p<0.05): stronger nitrogen-fixing ability, higher VA mycorrhizal development and better growth of seedlings in VAH and HR16 dual inoculation. 相似文献
999.
以北方盆栽蓝莓美登和北蓝为研究对象,通过人为温度控制,促使盆栽蓝莓提前开花。研究表明,盆栽美登(Blomidon)在需冷量达到1200h,盆栽北蓝(Northern blue)在需冷量达到1000h情况下,可以通过温度调控,打破盆栽蓝莓休眠期,达到提前开花的目的。 相似文献
1000.
龙烟7号是黑龙江省农科院牡丹江分院以密叶香为母本、牡晒84-1-5为父本杂交选育而成的晒烟新品种。2014年3月通过黑龙江省农作物品种审定委员会审定并定名推广。该品种植株为橄榄形,株型收敛、茎叶角度小,叶形宽椭圆,大田生育期84天,属中熟品种。幼苗及大田生长势强、整齐,烟叶成熟较集中。原烟外观质量优良,色泽红黄,油份较足,弹性好。高抗赤星病和普通花叶病。据多年多点试验结果,平均产量为2994kg/hm2,产值32963.9元/hm2,均价11.01元/㎏,中上等烟比例76.57%,分别比对照龙烟二号提高11.1%、15.9%、4.3%、5.5%。 相似文献