警惕椰子织蛾Opisina arenosella Walker （鳞翅目：织蛾科）传入中国

【背景】椰子织蛾是棕榈植物上的主要害虫。该害虫在印度和斯里兰卡危害严重,现已入侵泰国。【方法】在收集、整理椰子织蛾原产地或已知入侵地的生物学、生态学、地理学等信息的基础上,介绍了椰子织蛾的主要形态特征、寄主、分布、生物特性,并对该有害生物入侵我国的风险及后果进行综合分析。【结果】椰子织蛾幼虫通常为5龄,大多在棕榈植物叶背面为害。卵期约为5 d,幼虫期约为42 d,蛹期约为12 d,成虫产卵约为137粒。从适生性风险角度看,目前椰子织蛾在南亚和东南亚棕榈植物分布区危害严重,我国南方棕榈植物产区具有相似的生物气候,是椰子织蛾潜在的地理分布区;从传入扩散风险角度看,椰子织蛾成虫能够飞翔,且我国与该害虫发生国家特别是东盟国家的贸易日益频繁,加大了该害虫传入我国的可能性;从经济与生态风险角度看,椰子织蛾入侵我国后将危害椰子等棕榈植物,给相关产业带来损失,影响从业人员收入,同时影响本地生态环境,可能导致生态灾害。【结论与意义】椰子织蛾有入侵我国的可能,有效的检疫管理措施是防范其入侵的主要手段。生物防治是治理该害虫的重要措施之一。     

四种灌木状与四种乔木状棕榈植物热值的月变化

对 4种灌木状棕榈植物 (香棕、袖珍椰子、棕竹、江边刺葵 )与 4种乔木状棕榈植物 (假槟榔、董棕、国王椰子、大王椰子 )叶的热值和灰分含量的月变化进行了研究。结果表明 :( 1 ) 8种植物叶的灰分含量存在差异且具有不同的月变化 ;从灰分含量的比较看 ,乔木类的 4种植物叶平均灰分含量分别为 :假槟榔 1 3.64%± 2 .94%、董棕 9.74%± 1 .90 %、国王椰子 9.1 2 %± 1 .1 8%、大王椰子 8.69%± 3.5 5 % ;灌木类的 4种植物叶平均灰分含量分别为 :棕竹 8.73%± 2 .5 2 %、袖珍椰子 8.67%± 1 .1 9%、香棕 8.63%± 1 .2 0 %、江边刺葵 7.60 %± 0 .98% ,乔木类植物 (除大王椰子外 )叶平均灰分含量高于灌木类的植物 ;( 2 )从干重热值的月变化来看 ,分 3种类型 :江边刺葵与棕竹有相反的变化趋势 ;假槟榔、董棕、袖珍椰子的月变化趋势相同 ;国王椰子、香棕、大王椰子具有各自的变化趋势 ;在 8种棕榈植物中 ,除香棕外 ,灌木类的植物平均干重热值大于乔木类 ;灌木类中 ,茎单生的江边刺葵干重热值高于茎丛生的棕竹、香棕和袖珍椰子 ;( 3)假槟榔、袖珍椰子、大王椰子的干重热值与灰分含量具有极显著的线性相关 ( P<0 .0 1 ) ,棕竹的干重热值与灰分含量有显著的线性相关 ( P<0 .0 5 ) ;而香棕、董棕、江边刺葵、国王椰     

五种丛生状棕榈植物叶热值的月变化研究

对5种丛生状棕榈植物一欧洲棕、细叶棕竹、小箬棕、玲珑椰子、缨络椰子的叶片热值和灰分含量的月变化进行了研究,结果表明,5种植物具有较高的灰分含量,但灰分含量的月变化趋势各不相同;欧洲棕、细叶棕竹、小箬棕3种植物干重热值的月变化趋势有些差异,同属的缨络椰子、玲珑椰子干重热值的月变化趋势基本相似;缨络椰子、小箬棕的干重热值与灰分含量具有显著的线性相关(P<0．05),而其余3种植物的干重热值与灰分含量相关性不显著(P>0．05);从去灰分热值的月变化来看,细叶棕竹与小箬棕,缨络椰子与玲珑椰子的月变化趋势相似。     

椰子木蛾在中国的适生区预测

【目的】椰子木蛾Opisina arenosella Walker是2013年在海南、广东和广西等地新发现的棕榈植物的危险性入侵害虫,其入侵范围有不断扩大的趋势。【方法】应用CLIMEX软件对椰子木蛾在中国的潜在适生区进行了分析。【结果】结果表明椰子木蛾在中国适生范围广,长江以南广大地区均是其高度适生区。【结论】这些区域是我国棕榈植物的主要分布区,建议加强检疫和监测措施,防止其进一步扩散。     

海南发现椰子织蛾的重要天敌褐带卷蛾茧蜂

椰子织蛾是棕榈植物的重要入侵害虫,在印度和斯里兰卡严重危害椰子树。2013年在海南省万宁市首次发现椰子织蛾。目前,该虫已在海南多个市县及广东和广西危害,对我国棕榈科植物的安全生产构成严重威胁。2014年11月,作者等人在万宁兴隆和三亚海棠湾镇调查椰子织蛾危害时,发现其重要天敌昆虫——褐带卷蛾茧蜂。为了进一步了解褐带卷蛾茧蜂,本文对其形态特征、分布、寄主和生物学习性进行了报道,以便更好地用于椰子织蛾的生物防治。     

菊花近缘种属植物幼苗耐阴特性分析及其评价指标的确定

以龙脑菊、菊花脑、野菊等15个菊花近缘种属植物幼苗为材料,对其进行不同梯度遮荫处理(全光照,遮光率60%,遮光率78%,遮光率95%),从形态和生理等方面的22个指标进行测定,以各项指标的耐阴系数作为衡量耐阴性的指标,利用主成分分析、回归分析和聚类分析法对其耐阴性进行综合评价。结果表明:遮光率78%时的植物茎粗(X2)、叶片厚度(X10)、叶绿素含量(X16),遮光率60%时的植物叶绿素含量(X15),以及遮光率95%时的植物叶面积(X13)、相对含水量(X14)和胞间二氧化碳浓度(X21)8个指标可作为菊花近缘种属植物耐阴性评价指标,建立菊花近缘种属植物耐阴性评价的数学模型:Y=82.876-0.153X2+0.094X10+0.741X13+0.084X14+0.054X15-0.087X16-0.472X2,(R2=0.998),预测精度大于0.97。13份材料的耐阴性极强,矶菊的耐阴性较差,即多数菊花近缘种属植物具有较好的耐阴能力。     

新入侵害虫椰子织蛾的3种本地寄生蜂

【目的】椰子织蛾是近期入侵中国的棕榈植物重要害虫,研究其天敌寄生蜂,能为椰子织蛾的进一步防控提供科学依据。【方法】在海南岛收集鉴定了椰子织蛾天敌寄生蜂,观察记录寄生蜂发育历期、雌雄性比、成虫寿命等基础生物学特性。【结果】经形态及分子鉴定,收集到的椰子织蛾寄生蜂有幼虫期寄生蜂麦蛾柔茧蜂、蛹期寄生蜂金刚钻大腿小蜂和周氏啮小蜂。在温度(26±2)℃、湿度(75±10)%RH、以椰子织蛾为寄主条件下,麦蛾柔茧蜂、金刚钻大腿小蜂和周氏啮小蜂发育历期分别为11.8、19.6和20.6 d;每头寄主的出蜂量分别为10.1、1.0和81.5头;雌蜂占比分别为26.6%、40.6%和89.8%;每种寄生蜂雌蜂寿命均长于雄蜂。【结论】保护和利用椰子织蛾的3种本地寄生蜂,将有助于椰子织蛾的防控。     

椰子织蛾传入中国及其海南省的风险性分析

【背景】椰子织蛾原产于印度和斯里兰卡,现主要分布于南亚和东南亚,是椰子、中东海枣、蒲葵等多种棕榈科植物的重要害虫。我国目前尚无椰子织蛾发生为害的报道;但从适生性的角度看,该虫的地理分布区与我国南方棕榈植物分布区具有相似的生物气候,理论上我国热带、亚热带的广大区域是椰子织蛾的潜在地理分布区。鉴于其危害严重性,一旦入侵,其危险程度将超过已在我国发生的重要入侵害虫椰心叶甲。【方法】根据国际植物检疫措施标准（ISPM）规定的有害生物风险性分析（PRA）程序,利用相关风险性分析模型,从国内外分布状况、潜在的危害性、受害寄主的经济重要性、传播扩散的可能性及危险性管理难度5个方面,对椰子织蛾在中国及其海南省的风险性进行定性、定量分析。【结果】椰子织蛾在中国及其海南省的风险值（R）分别为2．20和2．30,在我国属于高度危险性有害生物。【结论与意义】本研究可为制定椰子织蛾的检疫管理对策提供依据。     

萼距花

萼距花(Cuphea)属千屈菜科,是生长在墨西哥和中南美洲的野生植物,其种子富含中链甘油三酸酯。1984年9月,美国许多农业学家、遗传学家和经济学家云集俄勒冈州,讨论萼距花的研究利用和发展趋势。他们预言20年后萼距花会成为美国油化学工业的新资源,它可以象椰子和棕榈一样提供月桂酸和癸酸,以生产表面活化剂。萼距花种子含多种类型的脂肪酸,如从C_8到C_(13),这在植物王国中是独一无二的。目     

薇甘菊提取物对椰子坚蚜的生物活性

【背景】薇甘菊为危险性入侵植物;同时椰子坚蚜为椰子上的重要害虫,对其防治方面的研究较少。研究薇甘菊次生物质对椰子坚蚜的生物活性可为薇甘菊的综合利用及椰子坚蚜的防治提供参考。【方法】采用室内生物测定的方法研究了薇甘菊4种溶剂提取物对椰子坚蚜的胃毒和触杀活性。【结果】供试的4种提取物中,正丁醇提取物和丙酮提取物对椰子坚蚜的胃毒水平较高,LC50分别为12.93和12.48 mg·m L-1,显著高于环己烷提取物和石油醚提取物。而4种提取物对椰子坚蚜的触杀毒力差异不显著,环己烷提取物、正丁醇提取物、丙酮提取物和石油醚提取物对椰子坚蚜的LC50分别为15.28、12.28、11.40和16.62 mg·m L-1。【结论与意义】薇甘菊提取物在椰子坚蚜防控中具有一定的应用潜力。     

Inter- and intraspecific relationships between shade tolerance and shade avoidance in temperate trees

Patterns of physiological and architectural adaptation and acclimation to decreasing light availability were investigated along a light gradient for saplings of 12 common species of temperate deciduous trees in southeastern Ontario, Canada. Physiological adaptation and acclimation (shade tolerance physiology) were quantified at the leaf level by measuring leaf mass per unit area (LMA), dark respiration per unit leaf nitrogen, chlorophyll per unit leaf nitrogen and the chlorophyll a:b ratio for the newest fully expanded leaf on the leader. Architectural adaptation and acclimation (shade avoidance) were quantified by measuring branching intensity and side shoot:main shoot length ratios for the most recent three years of growth on the leader and selected side branches. Within species, increases in LMA, chlorophyll a:b ratio and respiration per unit nitrogen and decreases in chlorophyll per unit nitrogen indicated that shade tolerance physiology generally increased with decreasing canopy openness. Increases in the branching intensity and side shoot:main shoot ratios of the leader and side branches indicated that shade avoidance also increased with decreasing canopy openness for the majority of species; however, in some species, stem bending under deep shade resulted in lateral growth. Interspecific variation in shade tolerance physiology was minimal when species were compared under equal amounts of canopy openness. In contrast, interspecific variation in shade avoidance variables was relatively high under equal canopy openness, with saplings of shade tolerant canopy species exhibiting higher shade avoidance than saplings of shade tolerant understory species.     

Hydraulics and life history of tropical dry forest tree species: coordination of species' drought and shade tolerance

Plant hydraulic architecture has been studied extensively, yet we know little about how hydraulic properties relate to species' life history strategies, such as drought and shade tolerance. The prevailing theories seem contradictory. We measured the sapwood (K(s) ) and leaf (K(l) ) hydraulic conductivities of 40 coexisting tree species in a Bolivian dry forest, and examined associations with functional stem and leaf traits and indices of species' drought (dry-season leaf water potential) and shade (juvenile crown exposure) tolerance. Hydraulic properties varied across species and between life-history groups (pioneers vs shade-tolerant, and deciduous vs evergreen species). In addition to the expected negative correlation of K(l) with drought tolerance, we found a strong, negative correlation between K(l) and species' shade tolerance. Across species, K(s) and K(l) were negatively correlated with wood density and positively with maximum vessel length. Consequently, drought and shade tolerance scaled similarly with hydraulic properties, wood density and leaf dry matter content. We found that deciduous species also had traits conferring efficient water transport relative to evergreen species. Hydraulic properties varied across species, corresponding to the classical trade-off between hydraulic efficiency and safety, which for these dry forest trees resulted in coordinated drought and shade tolerance across species rather than the frequently hypothesized trade-off.     

Global meta-analysis shows that relationships of leaf mass per area with species shade tolerance depend on leaf habit and ontogeny

It was predicted that relationships of leaf mass per area (LMA) with juvenile shade tolerance will depend on leaf habit, and on whether species are compared at a common age as young seedlings, or at a common size as saplings. A meta-analysis of 47 comparative studies (372 species) was used to test predictions, and the effect of light environment on this relationship. The LMA of evergreens was positively correlated with shade tolerance, irrespective of ontogeny or light environment. The LMA of young seedlings (相似文献   

Convergent Evolution towards High Net Carbon Gain Efficiency Contributes to the Shade Tolerance of Palms (Arecaceae)

Most palm species occur in the shaded lower strata of tropical rain forests, but how their traits relate to shade adaptation is poorly understood. We hypothesized that palms are adapted to the shade of their native habitats by convergent evolution towards high net carbon gain efficiency (CGE_n), which is given by the maximum photosynthetic rate to dark respiration rate ratio. Leaf mass per area, maximum photosynthetic rate, dark respiration and N and P concentrations were measured in 80 palm species grown in a common garden, and combined with data of 30 palm species growing in their native habitats. Compared to other species from the global leaf economics data, dicotyledonous broad-leaved trees in tropical rainforest or other monocots in the global leaf economics data, palms possessed consistently higher CGE_n, achieved by lowered dark respiration and fairly high foliar P concentration. Combined phylogenetic analyses of evolutionary signal and trait evolution revealed convergent evolution towards high CGE_n in palms. We conclude that high CGE_n is an evolutionary strategy that enables palms to better adapt to shady environments than coexisting dicot tree species, and may convey advantages in competing with them in the tropical forest understory. These findings provide important insights for understanding the evolution and ecology of palms, and for understanding plant shade adaptations of lower rainforest strata. Moreover, given the dominant role of palms in tropical forests, these findings are important for modelling carbon and nutrient cycling in tropical forest ecosystems.     

LEAF OPTICAL PROPERTIES ALONG A VERTICAL GRADIENT IN A TROPICAL RAIN FOREST CANOPY IN COSTA RICA

Leaf optical properties (400–1,100 nm) were compared for four species of rain forest trees with crowns in understory, mid-canopy, and canopy positions to test whether optical properties change with light environment. The species tested represent a spectrum of regeneration patterns ranging from shade tolerant to light demanding. Overall, leaf optical properties of the four species were similar. Differences in absorptance were small, but statistically significant among the species and positions along the canopy gradient. Species absorptance differences corresponded somewhat to shade tolerance; two of the shade species showed higher absorptance in lower light environments, while the sun species showed the reverse pattern. Specific leaf mass (leaf weight per unit area) and chlorophyll content per unit leaf weight also changed along the canopy gradient. Specific leaf mass was positively correlated and chlorophyll per unit leaf weight was negatively correlated with increasing light environment. Consequently, the efficiency of absorption, as represented by the absorptance per unit leaf weight, increased as light level decreased, largely due to changes in specific leaf mass. In contrast, efficiency of absorption per unit leaf chlorophyll was relatively constant with light environment for the two species measured for chlorophyll.     

鼎湖山南亚热带常绿阔叶林不同树种存活对邻体组成的响应差异

理解群落结构和动态的主导机制是生态学研究的基本目标之一。群落内树种的存活受到其邻近树木的显著影响。为探究不同树种的存活对邻体组成的响应差异, 本研究基于鼎湖山南亚热带阔叶林20 ha森林动态监测样地中常见的90个树种的存活监测数据和功能性状数据, 建立了一系列关于邻体效应的树种存活模型。结果表明: 约58%的树种存活对邻体组成有敏感的响应, 共存树种间的功能性状差异影响着50%的树种存活动态。不同树种对邻体组成的响应差异与其耐阴性相关, 耐阴能力较弱的树种更倾向于表现出对邻体的敏感性。低比叶面积、高叶干物质含量、木材密度和最大胸径意味着较强的耐阴能力, 与光资源利用策略有关的生态位分化可能是邻域尺度上物种共存的原因。本研究为量化邻体间的相互作用和解释局域群落的物种共存提供了新的视角。     

两种大吴风草的耐荫特性研究

本文通过田间试验和叶绿素分析对上海地区两个品种大吴风草的耐荫性进行初步研究,结果表明大吴风草是喜半荫,耐荫的植物。大吴风草在遮光率达86.4%环境中生长良好,因此在完全郁闭度的树林或灌木丛下作地被具有良好的景观效果。     

Plasticity in seedling morphology,biomass allocation and physiology among ten temperate tree species in response to shade is related to shade tolerance and not leaf habit

• Mechanisms of shade tolerance in tree seedlings, and thus growth in shade, may differ by leaf habit and vary with ontogeny following seed germination. To examine early responses of seedlings to shade in relation to morphological, physiological and biomass allocation traits, we compared seedlings of 10 temperate species, varying in their leaf habit (broadleaved versus needle‐leaved) and observed tolerance to shade, when growing in two contrasting light treatments – open (about 20% of full sunlight) and shade (about 5% of full sunlight).
• We analyzed biomass allocation and its response to shade using allometric relationships. We also measured leaf gas exchange rates and leaf N in the two light treatments.
• Compared to the open treatment, shading significantly increased traits typically associated with high relative growth rate (RGR) – leaf area ratio (LAR), specific leaf area (SLA), and allocation of biomass into leaves, and reduced seedling mass and allocation to roots, and net assimilation rate (NAR). Interestingly, RGR was not affected by light treatment, likely because of morphological and physiological adjustments in shaded plants that offset reductions of in situ net assimilation of carbon in shade. Leaf area‐based rates of light‐saturated leaf gas exchange differed among species groups, but not between light treatments, as leaf N concentration increased in concert with increased SLA in shade.
• We found little evidence to support the hypothesis of a increased plasticity of broadleaved species compared to needle‐leaved conifers in response to shade. However, an expectation of higher plasticity in shade‐intolerant species than in shade‐tolerant ones, and in leaf and plant morphology than in biomass allocation was supported across species of contrasting leaf habit.

     

Continuous and Fluctuating Leaf Phenology of Adults and Seedlings of a Shade‐tolerant Emergent Tree,Dipterocarpus sublamellatus,in Malaysia

Continuous leaf phenology, with sequential production of metamers, is usually found in pioneer species, but is rare in shade‐tolerant species. Because of the nature of ‘continuous’ growth, continuous phenology has seldom been related to meteorological factors. We studied the leaf demography of seedlings and tall trees of a shade‐tolerant emergent species, Dipterocarpus sublamellatus (Dipterocarpaceae), in Malaysia. Although leaf phenology of D. sublamellatus was classified as continuous, the rates of leaf production and leaf fall were not constant and greatly fluctuated during the census period. Seasonal patterns of leaf production and fall were not synchronized across tall trees in most combinations or between seedlings and tall trees. Mean number of leaves produced per month and its seasonal fluctuation were greater in tall trees than in seedlings. Moreover, relationships between leaf phenology and meteorological factors (monthly rainfall, net radiation, maximum and minimum temperature, and minimum relative humidity) differed among trees. This suggests that endogenous rhythms, i.e., differences in allocation of resources to growth and storage among trees, are important to fluctuations in leaf phenology. These patterns are in contrast to patterns found in various pioneer species with continuous phenology, in which rates of leaf production and fall are generally constant. Different patterns might be caused by differences in allocation to growth and storage between pioneer and shade‐tolerant species, and might be related to their regeneration strategies.     

Does shade improve light interception efficiency? A comparison among seedlings from shade-tolerant and -intolerant temperate deciduous tree species

Here, we tested two hypotheses: shading increases light interception efficiency (LIE) of broadleaved tree seedlings, and shade-tolerant species exhibit larger LIEs than do shade-intolerant ones. The impact of seedling size was taken into account to detect potential size-independent effects on LIE. LIE was defined as the ratio of mean light intercepted by leaves to light intercepted by a horizontal surface of equal area. Seedlings from five species differing in shade tolerance (Acer saccharum, Betula alleghaniensis, A. pseudoplatanus, B. pendula, Fagus sylvatica) were grown under neutral shading nets providing 36, 16 and 4% of external irradiance. Seedlings (1- and 2-year-old) were three-dimensionally digitized, allowing calculation of LIE. Shading induced dramatic reduction in total leaf area, which was lowest in shade-tolerant species in all irradiance regimes. Irradiance reduced LIE through increasing leaf overlap with increasing leaf area. There was very little evidence of significant size-independent plasticity of LIE. No relationship was found between the known shade tolerance of species and LIE at equivalent size and irradiance.