基于LiDAR的亚热带次生林林窗对幼树更新影响分析

以湖南亚热带次生林为研究对象,利用多时相机载激光雷达(Light detection and ranging,Li DAR)和野外调查数据对林窗及幼树进行监测,分析比较林窗对幼树密度分布和树高生长变化的影响。结果表明,林窗大小和位置对幼树密度分布都有显著影响,喜光树种幼树主要集中在小林窗的中心区或大林窗的过渡区,在大林窗中密度最大(647株/hm2),耐荫树种幼树主要集中在林窗的边缘区,在中等林窗中密度最大(941株/hm~2)。林窗大小对幼树树高生长有显著影响,喜光树种和耐荫树种幼树分别在大林窗和中等林窗中树高生长量最大(69.3 cm/a、57.7 cm/a),喜光树种幼树在中心区的树高生长量明显大于其他位置,耐荫树种幼树的树高生长量在位置上的差异不显著。线性混合模型分析显示林窗大小是促进幼树树高生长的最主要因素,幼树树高生长变化在不同林窗中呈聚集性。从幼树密度树高生长情况来看,50~150 m~2林窗较适合促进亚热带次生林的群落演替。     

九峰科技植物资源现状与保护对策

经过查阅历史档案、询问当事人及外业核查、调查,结果表明:九峰地区现有39块试验现场,面积124.7hm^2;实施各类科技项目53项,项目规模面积140.25hm^2,涉及裸子、被子等植物73科,150属,194种(类),已形成科技植物群体;在九峰森林植物本底调查、林木种质资源收集与保存、林木品种遗传改良及繁殖技术等13个学科方向及近120个植物品种开发研究方面取得了重大突破和创新;鉴于九峰科技植物资源现状,本文提出了相应的保护对策与措施。     

Influencing in vitro clonal propagation of Chonemorpha fragrans(moon) Alston by culture media strength,plant growth regulators,carbon source and photo periodic incubation

Chonemorpha fragrans is an endangered medicinal woody climber,regarded among alternative plant sources of camptothecin.Camptothecin is a monoterpene indole anti-cancer alkaloid with annual trade value of over three billion U.S.dollars in the recent,and is used in the production of its analog drugs approved for the chemotherapy of cancer of varied types.Effects of plant growth regulators,culture media strength and photoperi-odic duration on the micropropagation ef ciency of C.fragrans from nodal segment explants were studied on Murashige and Skoog(MS)medium amended with Thidiazuron(TDZ),Benzylaminopurine(BAP)or Kinetin(Kin).Thidiazuron was more ef cient over BAP and Kin when half basal MS medium was used over full or quarter strength.Results of carbon source experiment showed sucrose as the most effective over glucose,fructose,and maltose in the clonal production.Studies on the photope-riodic incubation duration showed 12 h as the best light period and sub or supra-optimal resulted in the production of abnormal and albino micro shoots.Experimental results on the evaluation of physiological,biochemical parameters showed the role of pigment molecules and antioxidant systems in the production of albino micro shoots.     

Development of a linear mixed-effects individual-tree basal area increment model for masson pine in Hunan Province,South-central China

ABSTRACT

An individual-tree basal area increment model was developed for masson pine based on 26276 observations of 13,138 trees in 987 sample plots from the 7th (2004), 8th (2009), and 9th (2014) Chinese National Forest Inventory in Hunan Province, South-central China. The model was built using a linear mixed-effects approach with sample plots included as random effects since the data have a hierarchical stochastic structure and biased estimates of the standard error of parameter estimates could be a consequence of applying ordinary least square (OLS) for regression. In addition, within-plot heteroscedasticity and autocorrelation were also considered. The final mixed-effects model was determined according to the Akaike information criterion (AIC), Bayesian information criterion (BIC), log-likelihood (Loglik), and the likelihoodratio test (LRT). The results revealed that initial diameter (DBH), the sum of the basal area (m²/ha) in trees with DBHs larger than the DBH of the subject tree (BAL), number of trees per hectare (NT), and elevation (EL) had a significant impact on individual-tree basal area increment. The mixed-effects model performed much better than the basic model produced using OLS. Additionally, the variance structure of the model errors was successfully modeled using the power function. However, the autocorrelation structures were not defined because there was no autocorrelation amongst the data. It is believed that the final model will contribute to the scientific management of the masson pine.     

面向老龄化社会的户外环境植物景观与健康效益评价模型建构

为了促进国内基于健康视角下户外植物景观可量化评价机制的形成与完善,归纳总结了健康景观以及普通植物景观中广泛存在的对人身心健康有促进作用的因素——植物的健康效益。从植物景观对人身心健康的影响机制手,分析户外景观环境中健康性要素构成,深入探究植物景观与老年人身心健康的作用机理,并初步构建了基于植物健康效益的适老性户外植物景观评价指标体系。     

中国再生稻种植的影响因素及可持续性研究进展

再生稻作为一种特殊的水稻耕作模式,种一茬可收获两次,对增加粮食产量、保障国家粮食安全和提高稻田综合效益有重大意义。综述了中国再生稻的发展趋势,分析了再生稻种植的关键影响因子,阐释了再生稻高产栽培技术,提出在种好头季稻的前提下,适当高留桩,在头季稻齐穗后15 d施用尿素150 kg·hm^-2作为促芽肥,头季稻收割后3 d施用尿素150 kg·hm^-2作为发苗肥,同时配施磷钾肥,可在保证土壤养分平衡的基础上使再生稻获得高产,最后讨论了当前存在的问题及今后发展的方向,认为未来的研究需重点关注再生稻产业化、土壤养分管理、高产栽培技术、稻米品质、温室气体和水体质量,以促进再生稻的发展并为国内同行的研究提供参考与借鉴。     

Inhibiting soil loss and runoff from small plots induced by an individual freeze-thaw cycle using three rangeland species

This study investigated the role of three rangeland species viz. Agropyron trichophorum, Medicago sativa, and Lolium prenne on mitigating of effects of a freeze-thaw (FT) cycle on runoff generation and soil loss from small experimental plots. Small plots (0.5 × 0.5m) were prepared in three replicates for control (i.e., under a FT cycle only) and treatments (i.e., individually planted with the study species and subject to a FT cycle). The treated plots were then placed at a slope of 20% and subjected to simulated rainfall with intensity of 70 mm h⁻¹ and 30 min duration. The results of the study showed a significant effect (P < 0.05) of the plants on controlling runoff and soil loss after a FT cycle. Also, the detrimental effects of the FT cycle due to performance of ice lenses and formation of an active melting layer in the soil surface were ameliorated by the presence of litter on the soil and root-binding effect of the plants. Time to runoff increased by 54, 111 and 10%, runoff volume decreased by 27, 68 and 0.4% and soil loss changed by −34, −62, and +6.5% in the plots planted with A. trichophorum, L. prenne and M. sativa, respectively. The results of the current study indicated that L. prenne had the maximum benefit on reducing runoff and soil loss from the plots undergoing a FT cycle.     

薰衣草茎段再生体系的建立

以薰衣草带芽茎段为外植体,探讨不同激素种类与水平等因素对其愈伤诱导、不定芽分化、增殖与不定根形成的影响,并筛选了薰衣草试管苗过渡移栽的适宜基质等。试验结果表明:不定芽启动培养以MS+BA1.0~2.0mg/L+蔗糖30g/L+琼脂6.5g/L为宜;继代增殖以MS+BA1.0~2.0mg/L+IBA0.25mg/L+GA1.0mg/L+蔗糖30g/L+琼脂6.5g/L为宜;不定根分化以White+IBA0.4mg/L+蔗糖20g/L+琼脂6.5g/L或White+NAA0.8mg/L+蔗糖20g/L+琼脂6.5 g/L为宜。     

植物组织培养快速繁殖类型综述

应用植物组织培养方法进行快速繁殖,具有繁殖速度快、能保持植株的优良性状等优点。其繁殖类型有无菌扦插、器官发生、器官直接转变型、胚状体发生和原球茎等类型。指出了组织培养快速繁殖技术目前存在的主要问题。     

东北过伐林椴树生长过程与生长模型的研究

利用吉林省汪清县金沟岭林场收集的38株过伐林椴树解析木资料,研究椴树年龄与树高、胸径、材积之间的相关关系,分别拟合椴树最优树高-年龄、胸径-年龄、材积-年龄的生长方程,经检验达到精度要求,为预测该地区椴树树高、胸径、蓄积的生长提供理论依据。