Effects of fragmentation on juvenile morphology of Acer saccharum Marsh. (sugar maple) in temperate forests of northeastern Ohio,USA

The influence of forest fragmentation on population and community dynamics of woody plants has been well established worldwide, but rarely at the level of an individual plant. We evaluated the influence of fragmentation on juvenile stem morphology of Acer saccharum Marsh. (sugar maple), while also examining light levels and considering possible confounding effects attributed to elevation gradients in temperate forests of northeastern Ohio, USA. At two sites, plant stem dimensions, canopy openness, and relative ground level elevation were measured using randomly positioned plots in forest edge and interior habitats that were within 25 and 60–100 m from a forest edge, respectively. Ratios of stem length to stem basal diameter were greater in forest interiors than near forest edges. These differences in stem morphology between habitats were likely a result of stem elongation in relation to a shade avoidance response in forest interiors that were consistently darker than forest edge areas across study sites. By contrast, such morphological differences were likely not related to variation in relative ground level elevation since a subtle elevation gradient was detected at only one site. We encourage experimentation to identify mechanisms that affect plant stem morphology of young individuals and its influence, in turn, on plant population dynamics in fragmented forests.     

Relationships between elm spanworm, Ennomos subsignaria, juvenile density and defoliation on mature sycamore maple in an urban environment

Using field surveys, we established sampling procedures for estimating defoliation resulting from elm spanworm, Ennomos subsignaria (Hübner) (Lepidoptera: Geometridae), feeding on mature sycamore maple, Acer pseudoplatanus L. (Aceraceae), in St. John's, Newfoundland and Labrador. We also determined whether densities of E. subsignaria eggs, egg masses, early- or late-instar larvae could predict the amount of defoliation at the end of the larval feeding period. Defoliation estimates acquired by sampling branches from only the lower, mid or upper crown explained ≥80% of the variation in tree-level defoliation, suggesting that density–defoliation relationships established using defoliation data from any crown level would also be useful for predicting tree-level defoliation. In linear regressions, egg and egg mass densities explained ≤20% of variation in defoliation and thus only provide a crude relative estimate of the amount of defoliation that will occur. Early- and late-instar larval density in the lower crown explained 53 and 29%, respectively, of the variation in defoliation in the lower crown, where defoliation levels were highest. Thus monitoring early-instar density in the lower crown should provide pest managers with reliable information for decisions regarding whether to apply suppression tactics while allowing enough time to implement these tactics, if necessary.     

美国红枫种胚愈伤组织诱导、增殖培养技术研究初报

对美国红枫种胚进行愈伤组织的诱导、增殖培养研究的结果表明：愈伤组织诱导最适培养基为1/2MS＋6-BA2＋IAA0.5,最适增殖培养基为1/2MS＋6-BA2＋NAA0.5,诱导和增殖培养基均附加1．5％葡萄糖、0．8％琼脂;无机盐含量低利于愈伤组织的诱导。     

皖北地区美国红枫高效繁育及栽培技术初探

美国红枫是重要的园林造景树种,目前引种繁育及栽培技术在皖北地区得到了一定的推广。通过实践中积累的经验,对该地区美国红枫的嫁接繁殖、扦插繁殖及栽培管理技术进行归纳总结,为进一步促进该地区美国红枫的推广及产业发展提供参考。     

辽东枫叶变色气象条件分析和气象指数研究

为了研究气象要素对枫叶变红时间、程度的影响并对赏枫的天气适宜度做出准确预报，本文利用2014—2017年辽东本溪、本溪县、桓仁3个国家级气象站9—10月的气象资料和关门山公园、老边沟景区、中华枫叶之路、枫林谷等16个监测区域65个监测样点枫叶物候观测资料，分析影响枫叶变色的气象条件及最佳观赏期特点，确定枫红气象指数的计算方法和等级划分。结果表明:（1）辽东山区进入初红状态平均时间是9月26日，进入正红状态平均时间是10月8日；枫叶进入初红状态的时间较初霜日有明显提前，进入斑红状态的时间和初霜日对应较好，有70%以上的样点在初霜日前1天到后1天之间进入斑红状态。（2）气温对枫叶变色的影响显著，在枫叶开始变色阶段，日平均温度、日最高气温和日最低气温越低，枫叶变色率越高；降水对枫叶变色也有一定的影响，7—9月降雨较多的年份，枫叶进入最佳观赏状态时间较晚，但枫叶观赏期较长。（3）每年9月16日之后，日平均气温在12~18℃时，枫叶进入初红状态；日平均气温在5~15℃时，枫叶进入正红状态；日最低气温低于10℃，并累积超过3天，进入初红状态；日最低气温低于6℃，并累积超过3天进入正红状态；气温日较差大于15℃，并积累超过3天，开始进入初红状态。（4）枫叶变色前都会经历一次明显的降温，初红状态出现在降温后的第1天或第2天，斑红状态出现在降温后的第3天或第4天。（5）根据分析结果建立枫红气象指数，划分为4级标准，分别为一级适宜、二级较适宜、三级不太适宜、四级不适宜，分级表征枫红的观赏适宜度，为游客赏枫提供参考。     

牛背梁自然保护区血雉种群数量与分布

2009年1月～2010年12月,采用路线调查与访问调查相结合的方法,对牛背梁保护区血雉种群数量与分布情况进行了调查。调查结果显示,血雉仅分布于牛背梁保护区境内秦岭主脊以南海拔1 725～2 615m的地带,而以光头山、小甘沟、牛背梁与花门楼地区海拔2 115～2 387m的分布最为集中。血雉在区内的分布面积为41.7km2。根据调查数据计算,牛背梁保护区境内血雉的间接数量为1 902只,在整个保护区内的平均分布密度为11.288只/km2。     

元宝枫种仁蛋白强化面包加工技术的研究

对元宝枫种仁蛋白强化面包的加工方法和工艺参数进行了研究。结果表明:加工出的面包蛋白质含量比对照鲜重提高了49.3%,干重提高了73.9%;其感官指标和理化指标均优于我国面包质量。     

The use of ultrapurified bovine hemoglobin solution in the treatment of two cases of presumed red maple toxicosis in a miniature horse and a pony

Objective: To report the use of ultrapurified bovine hemoglobin (PBHg) in the treatment of red maple toxicosis in horses. Summary: The use of PBHg in a miniature horse and a pony with clinical signs of red maple toxicosis is described. Initial treatment of the horses included blood transfusion in Case 1, and intravenous crystalloid fluids, nasogastrically administered mineral oil, and activated charcoal in both cases. Both cases received PBHg (16 and 11 ml/kg, respectively) when the hematocrit dropped below 10%. Clinical stabilization of the horses (reflected by improved vital signs and mucous membrane color, increase in P_vO₂, and increase in plasma hemoglobin) was temporary, lasting 12 and 42 hours, respectively. A whole blood transfusion was given 16 hours after the infusion of PBHg in Case 1 and 42 hours after the infusion of PBHg in Case 2. The horses were discharged on days 15 and 17, respectively. Both were stable on discharge and were reported to be doing well 1 month after discharge. New information provided: Ultrapurified bovine hemoglobin is shown to be safe in the treatment of red maple toxicosis. Ultrapurified bovine hemoglobin infusion resulted in temporary improvement in oxygen (O₂) delivery as assessed by clinical and laboratory parameters. The use of PBHg may provide an ‘oxygen bridge’ in an acute hemolytic crisis in the horse. It may allow additional time in the treatment of red maple toxicity for the acute hemolysis to subside and for metabolism of the toxin to occur, thus providing a more optimal environment for an effective whole blood transfusion.     

蔗糖和不同外源激素处理对美国红枫色叶的影响

针对美国红枫色叶率不足与色叶期较短的实际情况,进行蔗糖和不同外源激素处理试验。色叶率试验采用蔗糖8%、4%、2%三个处理;色叶期采用20mg/kg防落素、2000mg/kg比久、10mg/kg萘乙酸三种方案;均以清水喷施叶片为对照。试验结果表明：8%蔗糖对提高美国红枫色叶率效果最好,提高率高达122.9%;20mg/kg防落素对延长美国红枫色叶期效果最好,提高率达73.2%。