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81.
Radiographic evaluation of the pelvis in standing horses has been used to diagnose fractures of the pelvis, head and greater trochanter of the femur, and luxations of the coxofemoral joint. Coxofemoral luxation injuries are more common in smaller horse breeds and donkeys, but, due to their size, the standing ventrodorsal projection is not possible, as there is insufficient space to place the radiography equipment under the animal's abdomen. The objective of the study was to report the advantages and limitations of the use of an oblique radiographic projection to diagnose unilateral craniodorsal coxofemoral luxation in 3 ponies and a donkey performed with the animals standing under light sedation. All cases had severe unilateral hindlimb lameness and asymmetry of the gluteal region; 2 also had concurrent intermittent upward fixation of the patella. A standing dorsolateral 20–30° ventral oblique radiograph of the affected coxofemoral joint was performed in all cases to obtain a definitive diagnosis. Radiography of the coxofemoral joint in standing ponies and donkeys can be carried out to identify craniodorsal coxofemoral luxation avoiding the need for general anaesthesia. 相似文献
82.
晋西黄土丘陵沟壑区刺槐林适宜性评价 总被引:6,自引:0,他引:6
晋西黄土丘陵沟壑区水土流失严重,气候干旱,生态环境恶劣,适应性和抗逆性很强的刺槐是该区重要的优良造林树种。建国以来,该区营造了大面积的刺槐林,但由于各立地类型的光、热、水、气、肥等条件不尽一致,其生长状况相差悬殊,有的甚至形成"小老树"。为了研究刺槐林的生态适宜性,在对不同立地条件下刺槐林生长状况调查的基础上,应用Verhanlst生长预测模型和模糊最优局势决策法进行了分析,发现刺槐林的生长状况与各立地条件的土壤水分变化基本一致,不同立地条件下刺槐林生长差异显著,同时筛选出适宜于营造刺槐林的最佳立地条件类型是梁峁阴坡和阴沟坡。 相似文献
83.
Guo Renjian 《浙江林学院学报》1989,(2)
随机抽取50株马尾松解析木,经F检验,浙江省松立木二元材积表(二),适用于千岛湖封山育林地区。 相似文献
84.
Based on the diameter, height and biomass of different organs of Pseudosasa amabilis, an individual optimization model is established. The results showed that the relationships among diameter, height, and biomass of different organs followed the power function model, rather than exponential model, linear model, or polynomial model. The biomass proportion of large diameter grade increased apparently after culm harvesting, and diameter was mainly distributed from 4 to 5 cm diameter grade. The standing biomass of cultivated Pseudosasa amabilis was between 48.10 t·hm-2 and 53.10 t·hm-2, while standing biomass of non cultivated P. amabilis stand was between 66.90—70.40 t·hm-2, which is a suitable species for carbon sink. Bamboo individual biomass accounted for 70% of the above-ground biomass and grew multiply as the individual bamboo diameter increasing. The biomass of litter ranged from 8.32% to 18.10% in standing biomass while that of non cultivated bamboo stands was lower than that of cultivated bamboo. There existed a 1∶ 1 constant relationship between leaf biomass and branch biomass. 相似文献
85.
介绍了当盗伐、滥伐林木已被造林的立木材积测算方法。首选要测算包括原条材积、原木材积、锯材材积等已被造材的材积,再根据该材种的出材率换算成立木材积。 相似文献
86.
Yu-Hui Huang Yue-Lin LiYin Xiao Katherine O. WenigmannGuo-Yi Zhou De-Qiang ZhangMike Wenigmann Xu-Li TangJu-Xiu Liu 《Forest Ecology and Management》2011,261(7):1170-1177
Through the long-term measurement and development of a method for partitioning the products of decomposing litter, the impact of chemical components of forest debris on soil organic carbon (SOC) accumulation was studied in a forest succession series in South China. We quantified how litter quality is strongly correlated with the partitioning of respiration, dissolved organic carbon (DOC) and fragments of decomposing litter. In the succession sequence of 60-year-old pine forest (PF), to 80-year-old mixed pine and evergreen broadleaved forest (MF) to more than 400-year-old monsoon evergreen broadleaved forest (MEBF), the litter C/N ratios and lignin contents were gradually decreasing, which in turn were correlated with increasing litter decomposition constants (k-values), gradually shortening residence times of standing litter pool. And, 53.5%, 65.6% and 76.2% of the gravimetric litter mass losses were going belowground through both DOC and fragmentation. Correspondingly, the SOC accumulation rates in the top 20 cm of mineral soils for the three forests from 1978 to 2008 were 26 ± 4, 33 ± 5 and 67 ± 5 g C m−2 yr−1, respectively. Results of the study support the idea that in order to increase carbon sequestration in soils and long-term functional ability of forest ecosystems to act as carbon sinks, “Kyoto Forests” should be designed and reconstructed with a high diversity of broadleaved species, especially containing nitrogen-fixing trees. 相似文献
87.
山杨林病害与林分因子的关系及对立木材积的影响 总被引:1,自引:0,他引:1
根据山杨林的特征及其病虫害情况(山杨林的病害主要有混合干基腐朽和树干腐朽),论述了山杨林立木腐朽与林木年龄、林木组成、坡向的关系及对立木材积的影响。 相似文献
88.
Using quantification theory I, an analysis of the relation of soil water and qualitative factors, such as, slope degree, slope
aspect, slope position, and soil in Wangjiagou watershed area has been done. The study aims to quantify the factors influencing
soil water, the descending order of the factors being the slope aspect, soil, slope degree, and slope position, thereby scientifically
facilitating division of afforestation site types and afforestation site products digitally on geographical information system
(GIS).
__________
Translated from Journal of Northwest Forestry University, 2006, 21(3): 184–188 [译自: 西北林学院学报, 2006, 21(3): 184–188] 相似文献
89.
在湖北省崇阳县进行毛竹林丰产技术试验研究。结果表明,对毛竹林施行全垦施肥,刀抚全垦或刀抚除杂,均能收到提高毛竹产量和立竹质量的目的,其中全垦施肥和刀抚全垦有利于毛竹竹鞭孕笋,增产效果极为明显;刀抚除杂投资少,见效快,也有明显的增产效果,各地可因地制宜地采取适宜措施,改变竹林荒芜低产的状态,促使竹林复壮增产。 相似文献
90.
本文用兴安落叶松天然林19块标准地资料,分析了林分枯立木年龄结构;并用三参数Weibull函数拟合了林分枯立木的龄阶分布,经X~2-检验,结果表明拟合效果良好。同时研究了林分活立木年龄与枯立木年龄之间的关系以及天然林的抚育问题。 相似文献