Pollination systems in a warm temperate evergreen broad-leaved forest on Yaku Island

Animal pollination in a warm temperate evergreen broad-leaved forest was observed on Yaku-shima Island, south of Kyushu, Japan. Three groups of plants were categorized: canopy-flowering tree species, understory-flowering tree species, and climber and epiphyte species. Each of these formed different pollination systems. The canopy-flowering tree species had shallow, dish-shaped flowers and utilized various types of opportunistic pollinators. Most of the climber and epiphyte species had deep, tube-shaped flowers and specialized pollinators, although some climber species which bloomed in the canopy especially in winter, had opportunistic pollinators. The understory-flowering tree species had large dish- or funnel-shaped flowers and endothermic pollinators able to tolerate the dark and cold conditions under the canopy. The individual trees of canopy-flowering tree species produced large numbers of flowers simultaneously (mass-flowering) and had a well synchronized flowering period. Each canopy-flowering tree species segregated its flowering time from those of the anothers. Climber and epiphyte species and most of the understory-flowering tree species produced small numbers of flowers sequentially (extended flowering) and showed a long flowering period.     

广西猫儿山不同海拔常绿和落叶树种的营养再吸收模式

土壤养分供给性大小是否影响植物氮和磷再吸收效率仍存在争议。调查了广西猫儿山不同海拔常绿和落叶树种成熟和衰老叶片的氮和磷含量,探讨营养再吸收是否受到叶片习性和海拔的影响。所有树种氮和磷再吸收效率的平均值分别为56.5%和52.1%。常绿树种比落叶树种有显著较高的氮再吸收效率(P0.001)和磷再吸收效率(P0.01),这与前者有较低的衰老叶片氮和磷含量密切相关。随着海拔的上升,氮再吸收效率显著下降(P0.01),磷再吸收效率显著提高(P0.05)。氮再吸收效率与土壤氮:磷比(r=-0.41,P0.05)和成熟叶片氮:磷比(r=-0.37,P0.05)负相关,磷再吸收效率与土壤氮:磷比(r=0.44,P0.05)和成熟叶片氮:磷比(r=0.47,P0.01)正相关,表明了树种对低海拔氮限制的适应逐渐转变为对高海拔磷限制的适应。此外,氮再吸收效率与年均温正相关(r=0.43,P0.05)而磷再吸收效率与年均温负相关(r=-0.45,P0.01),这表明气温也是调节树木营养再吸收格局的重要影响因素。不同海拔树种氮和磷再吸收模式的差异可能是引起广西猫儿山常绿树种沿海拔形成双峰分布的原因之一。     

亚热带岩溶区典型常绿和落叶树种的蒸腾特征及其对环境因子的响应

植物蒸腾是水循环的重要组成部分,为了解亚热带岩溶区树木的蒸腾耗水情况,探究气候和水文地质条件对植物蒸腾的影响,运用Granier热耗散探针技术,对亚热带岩溶区次生林内的常绿树种女贞(L.lucidum)和落叶树种刺槐(R.pseudoacacia)的树干液流进行了连续监测,并同步监测了气象因子及土壤含水率(SMC),探讨在不同时间尺度下两种生活型树种的蒸腾特征及其对环境因子的响应。结果表明：(1)在季节尺度下,影响两树种整树蒸腾量(ET)的主要因子为太阳辐射强度(Rs)、气温(T)和水汽压亏缺(VPD);女贞蒸腾量(ET_L)表现为夏季(1.29 kg/h)>春季(0.57 kg/h)>冬季(0.15 kg/h)>秋季(0.13 kg/h),刺槐蒸腾量(ET_R)表现为夏季(0.90 kg/h)>春季(0.31 kg/h)>秋季(0.16 kg/h)>冬季(0.04 kg/h)。(2)在日尺度下,晴天两树种ET呈现出明显的单峰日变化,且主要影响因子均为T、VPD和Rs;但由于常绿和落叶树种的生理特征差异,降雨时...     

Structure and regeneration of canopy species in an old-growth evergreen broad-leaved forest in Aya district,southwestern Japan

The population structure and regeneration of canopy species were studied in a 4 ha plot in an old-growth evergreen broad-leaved forest in the Aya district of southwestern Japan. The 200 m × 200 m plot contained 50 tree species, including 22 canopy species, 3,904 trees (dbh5 cm) and a total basal area of 48.3 m²/ha. Forty one gaps occurred within the plot, and both the average gap size (67.3 m²) and the total area of gap to plot area (6.9%) were small. Species found in the canopy in the plot were divided into three groups (A, B, C) based on size and spatial distribution patterns, and density in each tree size. Group A (typical species: Distylium racemosum, Persea japonica) showed a high density, nearly random distribution and an inverse J-shaped size distribution. Species in group B (Quercus salicina, Quercus acuta, Quercus gilva) were distributed contagiously with conspicuous concentration of small trees (<5 cm dbh) around gaps. However, the species in this group included few trees likely to reach the canopy in the near future. Group C included fast-growing pioneer and shade intolerant species (e.g. Cornus controversa, Carpinus tschonoskii, Fagara ailanthoides), which formed large clumps. Most gaps were not characterized by successful regeneration of group B and C but did appear to accelerate the growth of group A. Group B species appear to require long-lived or large gaps while group C species require large, catastrophic disturbances, such as landslides, for regeneration.     

Climate-growth relationships of deciduous and evergreen Nothofagus species in Southern Patagonia,Argentina

Differences in growth patterns between a deciduous species, Nothofagus pumilio, and an evergreen species, Nothofagus betuloides, were analyzed in Lago del Desierto, southern Patagonia, Argentina (49°01′ S – 72°52′ W). The relationships between the growth rate of these two species and variations in temperature, precipitation, and the Southern Annular Mode (SAM) were also evaluated. We processed and analyzed 54 samples of N. pumilio and 48 of N. betuloides and developed two tree-ring width chronologies covering the periods of 1754-2014 and 1650-2014, respectively. The results from N. betuloides are especially important due to the small number of studies about this species in the area. Results indicate similarities between the tree-ring growth patterns of the two species. However, N. betuloides grew with a slower rate and had shorter periods of growth below average. We suggest that the particular growth pattern of N. betuloides is determined by its higher tolerance to stress situations and evergreen physiological characteristics. Significant correlations were observed between N. pumilio tree-ring growth and temperature from August-October of the previous year, and with the SAM index from December-January of the current year. N. pumilio did not show significant correlations with precipitation. Significant correlations were found between N. betuloides growth and precipitation from December-January of the previous year. As evergreen species have a more conservative response to temperature changes, N. betuloides growth was not significantly affected by temperature or by the SAM index. These results are encouraging and further studies could help improve our understanding of the relationship between the environment and species with different seasonality of foliage growth. Our study provides the first chronologies of N. pumilio and N. betuloides in the area and increases knowledge about the relationships between tree-ring growth and climate.     

格氏栲自然保护区常绿阔叶林群落特征

在11000m²样地调查材料的基础上,分析了福建三明格氏栲自然保护区常绿阔叶林群落的种类组成、乔木种群的重要值、群落外貌、物种多样性、水平结构和垂直结构特征。该群落计有维管植物223种,隶属于80个科159属,其中单种属占总属数的80.5%,包括藤本在内的高位芽植物占总种数的85.2%。重要值高的乔木种群是格氏栲、木荷、米槠、马尾松、刮槠和山黄皮。主要乔木种群均服从聚集分布。群落垂直结构复杂,可分为乔木层、灌木层和草本层。生活型谱和物种多样性指数介于南亚热带季风常绿阔叶林和中亚热带常绿阔叶林之间。     

广西常绿阔叶林分类系统及特点

常绿阔叶林是广西分布最广泛、最为复杂多样的植被类型.遵循《中国植被》一书的植被分类原则,并参考宋永昌先生的《中国常绿阔叶林分类试行方案》.根据高级单位以生态外貌、中级单位以优势度类型、低级单位以特征种组的分类原则,将广西常绿阔叶林划分出5个植被亚型、11个群系组和102个群系.在5个植被亚型中,典型常绿阔叶林和季风常绿...     

Surface area of woody organs of an evergreen broadleaf forest tree in Japan and Southeast Asia

Architecture of evergreen broadleaf trees in evergreen warm-temperate and tropical forests was analyzed with a ratio (U/Ac) of total surface area of aboveground woody organs to leaf area (one-sided surface area) of each felled tree. The ratio,U/Ac, tended to decrease with the increasing ofdbh. There was little difference in a range of the ratio at eachdbh class between a warmtemperate forest and a tropical rainforest. The ratios of larger trees correlated with their relative growth rates ofdbh among similar sized trees. Canopy trees tended to stop their growth at some value of a ratio, a threshold value being about 1.5, irrespective of forest types. The threshold value showed the critical condition that annual respiration of woody organs of a tree consumed nearly all surplus production. On the basis of the pipe model, an ideal maximum tree height was considered with the ratio, and was estimated at 110 m and 70 m in a tropical rainforest and a warm-temperate forest, respectively.     

Molecular species delimitation methods recover most song‐delimited cicada species in the European Cicadetta montana complex

Molecular species delimitation is increasingly being used to discover and illuminate species level diversity, and a number of methods have been developed. Here, we compare the ability of two molecular species delimitation methods to recover song‐delimited species in the Cicadetta montana cryptic species complex throughout Europe. Recent bioacoustics studies of male calling songs (premating reproductive barriers) have revealed cryptic species diversity in this complex. Maximum likelihood and Bayesian phylogenetic analyses were used to analyse the mitochondrial genes COI and COII and the nuclear genes EF1α and period for thirteen European Cicadetta species as well as the closely related monotypic genus Euboeana. Two molecular species delimitation methods, general mixed Yule‐coalescent (GMYC) and Bayesian phylogenetics and phylogeography, identified the majority of song‐delimited species and were largely congruent with each other. None of the molecular delimitation methods were able to fully recover a recent radiation of four Greek species.     

常绿阔叶树种的耐低温特性及其生态学评价

选取在南京地区已露地引种的 2 4种常绿阔叶树种 ,其自然分布北界止于亚热带不同的纬度 ,运用生理生态方法 ,测定它们在模拟低温处理下的电导率 ,并结合寒冷指数和引种后其适应性表现 ,分析这些树种的耐低温能力。结果表明 ,以某一树种自然分布北界气象资料为依据的寒冷指数与其自然植被的水温条件关系更为密切 ,寒冷指数有时不能反映树种本身耐低温能力的高低。如乐东拟单性木兰 ,其自然分布于亚热带南部 2 6°N,引种到南京耐低温表现明显好于自然分布于亚热带北部的香樟。而采用低温循环仪自动降温程序模拟冰冻处理来测定离体叶片的相对电导率 ,计算出各常绿阔叶树种叶片的半致死温度 ,能定量地反映这些树种本身的耐低温能力高低。在测试中如借助已知耐低温能力的树种作对照 ,其数据结果可作为常绿园林阔叶树种能否向更高纬度引种的重要参考依据。在上述研究基础上选出 6种 ,以其离体叶片为试材 ,测定其可溶性糖和游离脯氨酸含量 ,结果显示 ,随处理温度的降低 ,可溶性糖和游离脯氨酸的含量呈增加趋势 ,然而只有在适宜的处理下才呈现规律性变化 ,这些研究结果可作为树种耐低温能力的定性补充证据。对常绿阔叶树种的耐低温能力评价及预测有重要的参考价值     

Role of evergreen foliage in the nitrogen economy during shoot growth ofTernstroemia gymnanthera,a warm-temperate broadleaf tree

Accumulation and redistribution of nitrogen were examined during the shoot growth ofTernstroemia gymnanthera, a warm-temperate evergreen broadleaf tree species. Measurements and analyses were confined to the shoot units comprising 2-year-old, 1-year-old and developing current shoots with the foliage of respective ages. Budbreak occurred in early May and nitrogen was rapidly translocated into curent shoots with the progress of their growth. In all of the old organs of the shoot unit, nitrogen concentrations decreased gradually from the time of budbreak to early July. During this period, those old organs supplied more than 60% of the amount of nitrogen needed for the developing current shoots within the same shoot unit. The rest was supplied from the basal organs outside the shoot units comprising branches older than 2 years, stem and roots, by redistribution and/or by absorption from soil. Old leaves, mainly 1-year-old ones, provided about 72% of the total nitrogen derived from the old organs in the shoot units. It was concluded that the evergreen broadleaves served as a large source of nitrogen for the early shoot growth.     

Leaf growth pattern in evergreen and deciduous species of the Central Himalaya,India

Leaf growth patterns were investigated in 11 evergreen (with leaf life-spans of just more than 1 year) and 15 deciduous species, occurring along an elevational gradient of 600–2200 m elevation in the Central Himalaya. Records were made of the leaf initiation period, leaf population dynamics, leaf expansion, leaf mass changes, leaf longevity and related parameters. Species of both groups produced leaves at similar rates during March to April, the driest period of the year. Species of both groups had approximately fully developed foliage during the warm, wet period (mid-June to mid-September) of the monsoon. However, significant differences were found at group level in other characters: shoot length (19.5 cm per shoot for deciduous and 11.7 cm for evergreen species); leaf population per 10 cm shoot length (4.7 vs 15.0); leaf area (107.9 vs 41.4 cm²/ leaf); specific leaf mass (106.9 vs 191.3 g/m²); and leaf mass loss after the monsoon period, being rapid and higher (31.6%) in deciduous species and slow and limited in the evergreens (26.2%). However, species of the two groups showed considerable overlaps in the values of above characters. The evergreen species of the Central Himalaya resembled the deciduous species of the region more than the multi-year leaves of clearly evergreen species. The evergreens bear leaves throughout the year, but like deciduous species bear the cost of annual replacement of old leaves by new leaves. They seem to outcompete deciduous species by producing annually a greater mass of leaves of low-carbon cost (per unit leaf mass), which is capable of conducting photosynthesis all year round. A situation of less marked contrast between favourable and nonfavourable periods, with respect to temperature, seems to favour the leaf characters of the evergreens.     

Leaf longevity in evergreen shrubs: variation within and among European species

Summary Leaf longevities were determined for 16 species of evergreen shurbs (Ericaceae and Empetraceae) at different habitats at three latitudes (c. 47°, 55–58° and 68°N) in central and north Europe to determine whether any general trends exist in variation in leaf longevity within and among species. Among these species and sites, mean leaf longevity varied between 1.4 and 3.8 seasons, which is similar to the values reported for other evergreen shrubs, but shorter than for many evergreen conifers. Consistent differences in leaf longevity were found when comparing latitudes (ignoring altitude and habitat type): longevities were longer at 68°N than at the two lower latitudes. No consistent trends were found among species within altitudes.     

Site‐to‐site variability and temporal trends of DOC concentrations and fluxes in temperate forest soils

Here, we report site‐to‐site variability and 12–14 year trends of dissolved organic carbon (DOC) from organic layers and mineral soils of 22 forests in Bavaria, Germany. DOC concentrations in the organic layer were negatively correlated with mean annual precipitation and elevation whereas air temperature had a positive effect on DOC concentrations. DOC fluxes in subsoils increased by 3 kg ha^?1 yr^?1 per 100 mm precipitation or per 100 m elevation. The highest DOC concentrations were found under pine stands with mor humus. Average DOC concentrations in organic layer leachates followed the order: pine>oak>spruce>beech. However, the order was different for mean DOC fluxes (spruce>pine>oak>beech) because of varying precipitation regimes among the forest types. In 12 of 22 sites, DOC concentrations of organic layer leachates significantly increased by 0.5 to 3.1 mg C L^?1 yr^?1 during the sampling period. The increase in DOC concentration coincided with decreasing sulfate concentration, indicating that sulfate concentration is an important driver of DOC solubility in the organic layer of these forest sites. In contrast to the organic layer, DOC concentrations below 60 cm mineral soil depth decreased by <0.1–0.4 mg C L^?1 yr^?1 at eight sites. The negative DOC trends were attributed to (i) increasing adsorption of DOC by mineral surfaces resulting from desorption of sulfate and (ii) increasing decay of DOC resulting from decreasing stabilization of DOC by organo‐Al complexes. Trends of DOC fluxes from organic layers were consistent with those of DOC concentrations although trends were only significant at seven sites. DOC fluxes in the subsoil were with few exceptions small and trends were generally not significant. Our results suggest that enhanced mobilization of DOC in forest floors contributed to the increase of DOC in surface waters while mineral horizons did not contribute to increasing DOC export of forest soils.     

浙江天童国家森林公园常绿阔叶林种间相关的研究

应用Ｘ２检验、联结系数ＡＣ、点相关系数ＰＣＣ和Ｐｅａｒｓｏｎ相关系数ｒ正公式研究了浙江天童国家森林公园常绿阔叶林植物的种间相关,将所测定的乔木层和灌木层植物分别划分为２个种组,即乔木层木荷＋苦槠组和青冈＋红楠组;灌木层木荷幼树＋　木组和红楠幼树＋长果桂幼树组．     

季风常绿阔叶林不同恢复阶段藤本植物的物种多样性比较

藤本植物是森林生态系统的重要组成部分,影响群落的恢复与演替。通过对云南普洱地区不同恢复阶段(恢复15a、恢复30a和原始林群落)季风常绿阔叶林群落的野外调查,分析了不同恢复阶段藤本植物的物种丰富度、密度、多度、径级分布、多样性指数及攀援方式,并探讨藤本植物与支持木的关系。结果表明:在0.81hm²的调查样地中,共发现DBH≥0.1cm的藤本植物1292株(分属34科51属64种)。原始林群落的藤本物种丰富度、密度(DBH＜1cm)、胸高断面积和平均胸高断面积都显著高于恢复阶段,原始林和恢复15a群落的密度(DBH≥1cm)、平均胸径和平均长度之间无显著差异,但都显著高于恢复30a。3种群落类型中藤本植物的物种组成和径级分布有显著差异,原始林中藤本植物物种更多,而且大径级(DBH≥10cm)的藤本植物仅出现在原始林及恢复30a的群落。单株藤本攀援的支持木在3种群落类型中均占多数,藤本植物与支持木的胸径存在显著的正相关(P＜0.001),原始林群落中DBH≥15cm的支持木更易被攀援,而恢复阶段则相反。茎缠绕藤本植物对原始林的负面影响要显著少于恢复15a及30a群落,而卷须类藤本植物也反映出原始林正处于一个动态变化的阶段,同时根攀缘和搭靠类藤本植物物种组成和多度变化可以反映出干扰后季风常绿阔叶林的恢复程度。森林砍伐是影响不同恢复阶段藤本植物的物种组成和分布的主要因素。