Taking Yunnan section of Yunnan-Vietnam railway as the research object, and the construction of greenway network is taken as the goal. The differences of the source level and retention status of the remaining stations are taken into account. Firstly, the station is taken as the ′source′ and the weighted Voronoi model is used to carry out the spatial division of resource point. Reuse MCR extension model to build the greenway network and realize effective combination of Voronoi and MCR. The selection of elevation, slope, relief degree, land use and other factors, on the weight assignment, integration along the important natural humanities resources, using ArcGIS technology platform for weighted superposition, the railway section on the greenway construction suitability analysis and the greenway network. The results showed that the Yunnan-Vietnam Railway greenway network has circular nature. It connects 8 cities including the urban area of Kunming City, Yiliang County, Mile County, urban concentration area of Mile City, Kaiyuan City, Mengzi City, Jianshui County, and Shiping County, as well as 200 important natural and cultural resources. The construction of Yunnan-Vietnam railway greenway network has a strong positive effect on integrating spatial resources, promoting the coordinated development of central Yunnan, and making full use of industrial heritage.
1-MCP was used to promote the latex regeneration of tapping panel dryness（TPD） trees in this study. The bark structure and latex physiological parameters, such as latex yield, inorganic phosphorus, thiol,sucrose contents and lutoid bursting index, were measured during TPD tree recovery. The results showed that the bark structures of TPD trees had an obvious change during TPD tree recovery. The number of effective laticifers increased in yellow skin, and the areas of stone cells and swelling laticifers decreased in the barks. From the changes of latex physiological parameters, the latex yield showed a significant increase trend during TPD tree recovery. The latex yield of TPD trees from the control was 19.89 mL, and the yield significantly rose to the maximum of 151.17 mL when the TPD trees recovered the latex flow. The thiol and inorganic phosphorus both firstly decreased and then increased. The contents of thiol and inorganic phosphorus were 0.64 mmol/L and 11.26 mmol/L before treatments, respectively. Their contents both significantly rose to the maximum of 1.19 mmol/L and 14.56mmol/L when the TPD trees recovered the latex flow, respectively. The sucrose content had an obvious rise trend,which is consistent with the change of latex yield. However, the lutoid bursting index significantly dropped to the minimum of 13.47% when the TPD trees recovered the latex flow. Overall, the changes of the thiol, inorganic phosphorus and sucrose contents were positive correlations with the latex yield, and the change of the lutoid bursting index was negative correlation with the latex yield during TPD tree recovery.
蜡状芽孢杆菌BS16 是从松墨天牛肠道筛选获得的 1 株具有纤维素酶活性的细菌,为了解BS16 的菌株基因组特性及其纤维素降解功能,采用扫描电镜、基因组学分析、DNS法探究BS16 的形态特征、纤维素酶解基因、纤维素酶活.结果表明:BS16 的细胞为胶囊状,长为 3～4 μm,直径为 0.5～1.2 μm;蜡状芽孢杆菌 BS16 基因组全长 5 347 914 bp,包含 5 494 个基因,其中包括5 338 个蛋白质编码基因、11 个rRNA基因、102 个tRNA基因和 17 个sRNA基因;BS16 基因组中主要由GH4、GH5、GH8、GH13 家族编码纤维素酶;蜡状芽孢杆菌BS16 具有完整的纤维素酶系,在其分泌的纤维素酶中内切葡聚糖酶活性最高为(2.186±0.081)U/mL,其内切葡聚糖酶的酶活性最适pH值为 5.0、最适温度为 40℃.
以奈曼沙漠化研究站内立地条件基本一致的小叶杨与樟子松混交林作为实验样地,运用空间结构参数的一元分布及三元分布分析小叶杨-樟子松混交林的空间结构特征,运用Ripley's K函数分析小叶杨与樟子松混交林的空间分布格局与种间关联性.结果表明:樟子松的株数主要集中在12 cm径级,小叶杨的株数主要集中在 6cm径级.小叶杨-樟子松混交林的角尺度 2/3 为随机分布,1/3 为聚集分布;大小比数分布频率较为均匀,主要为中庸分布;混交度较小,主要为弱度混交与中度混交之间.当M和U保持不变时,随着W的增加,小叶杨-樟子松混交林的相对频率以W=0.5 为中轴呈现正态分布;当W和M保持不变时,小叶杨-樟子松混交林的U分布状况在范围[0,0.25]>[0.75,1].在 0～25 m空间尺度上,小叶杨、樟子松种群主要为随机分布和聚集分布,其中随机分布的情况占大多数,小叶杨和樟子松间主要为不相关性.小叶杨-樟子松混交林是一种人工和天然相结合的混交林,水平分布格局为随机分布,大小比数为中庸分布,混交程度为中度混交,且小叶杨与樟子松的种间关联性相互竞争较弱,所以合理地调整与优化林分的空间结构可以使演替朝着理想的方向发展.
以 1 年生云南松苗木为材料,采用随机区组设计,对春季、夏季、秋季平茬后云南松苗木的萌蘖增长数量、萌蘖累计数量、萌条长度进行测定与分析,筛选出能提高云南松苗木萌蘖能力合理的平茬季节,并探讨云南松苗木萌蘖能力对平茬季节的响应规律.结果表明:在不同季节平茬后,云南松苗木的萌蘖增长数量随着苗木生长时间的推移呈现先增长后下降的趋势;不同平茬季节萌蘖累计量差异显著,春季平茬显著高于夏季平茬且显著低于秋季平茬,平茬后第 90 天春季、夏季和秋季的萌蘖累计数量分别为 11.6、11.4、13.6 条;不同萌条长度等级的比率有差异性变化,从萌条等级比率来看,不同季节萌条长度差异显著,春季平茬萌条长度显著高于夏季平茬和秋季平茬.因此,云南松萌蘖能力对不同季节平茬的响应是不同的,春季对云南松进行平茬可以促进萌蘖的出生以及萌条的生长,同时提高萌条质量,可以获得较为优质的萌条.
