广西药用植物园秋色叶植物资源调查及景观分析

通过对广西药用植物园内秋色叶种质资源、习性、园林应用情况进行调查研究.结果表明:调查范围内常用秋色叶植物约13科41种,其中乔木36种,灌木5种,落叶植物38种,常绿3种.在园林上的应用以群植、片植居多.在叶色上黄色居多.在调查研究基础上提出了改善广西药用植物园秋色叶植物应用的建议.     

长沙市白蚁种类及危害情况调查

报道了长沙市区危害房屋及园林树木的白蚁种类及危害状况，经5年调查(2000年-2004年)结果表明：长沙市(不包括长、望、浏、宁四县)共有白蚁2科17种．主要危害房屋的为散白蚁及台湾乳白蚁，危害园林树木的是黑翅土白蚁及黄翅大白蚁．讨论了区系特点及近年危害新状况。     

论水生观赏植物的造景艺术

水生观赏植物是水体绿化、美化和净化不可缺少的材料,也是园林水景的主要构景要素.在园林水景中,利用水生观赏植物洒脱的姿形、优美的线条、绚丽的色彩及水生观赏植物的生态作用、水生观赏植物的意境美,通过艺术构图和造景手法,创作出一幅幅具有诗情画意、环境优雅的园林景观.从水生观赏植物造景概述、环境因子与水生植物的景观效果及水生观赏植物的造景艺术与手法,论述水生观赏植物的造景功能及其在园林中的应用.     

百色城市园林绿化树种调查研究

通过对百色城区园林树种的调查研究,分析当地园林绿化树种应用中存在的问题,并对树种的选择和配置提出了建议,为今后园林规划设计中合理选择、利用绿化树种提供参考.     

秋季羰基硫在植物与大气间的交换

利用静态箱法研究了秋季羰基硫(COS)在六种北京常见树种与大气间的交换．结果表明：法国梧桐、槐树、龙爪槐、玉兰、柳树对COS有吸收，油松没有吸收,树木与大气间COS的交换通量受树种、环境温度、光照、COS初始浓度等因素的影响．一般来说．温度高、光照强时，以上树种与大气间COS的交换强；空气中COS初始浓度高时，植物对COS的吸收通量高,植物对COS的吸收达到饱和较植物对CO2的吸收以及异戊二烯的排放持续时间长．     

城市园林公墓中林木的水土保持效益

城市园林公墓的生态建设是我国生态环境整治的重要环节,其核心是造林绿化和水土保持。松柏类乔木是目前我国公墓绿化主要树种,但对它们控制水土流失的生态功能却不十分清楚。本文探讨了园林公幕绿化树木绿蚀控制机制和潜能。研究发现,林木具有缓冲高强 度降雨对土壤的滴溅侵蚀和减少有效降雨的能力,使林下土壤溅蚀量减少了约２０％,土壤流失量降低了４３．２０％,同时,树通过其根系的牵引效应根据际土层的抗滑动能力提高了３     

论园林树木栽培学(各论)的精讲教学法

园林树木栽培学是一门实践性很强的有关园林绿化领域的专业课、必修课.1995年以来,本人在园林树木栽培学各论教学中尝试重点讲解、课堂点评的教学方法,取得了较好的教学效果.     

特大降雪灾害对淮南市园林绿化树木损害的特征

2018年1月初发生特大降雪后,对淮南市4种类型的城市绿地中树木雪灾受损情况进行了调查。将受损树木分为6个受损类型,确定所有胸径(地径)高于6 cm受损树木的受损等级;分析不同生长型(常绿/落叶)树种的受损特征,利用Pearson相关分析,分析胸径(地径)、树高以及树冠重叠度与树木受损之间的关系;计算不同树种受损指数,并利用单因素方差分析判断不同树种受损指数之间的差异。结果表明,调查范围内树木受损较严重,有23种5 181株树木存在不同程度的受损,轻度受损、中度受损和重度受损个体占总受损个体比例分别为36.15%、44.53%和19.32%;生长型(常绿/落叶)是影响树木受损的重要因素,常绿树种在各个受损等级均高于落叶树种;随着胸径的增加,树木受损的比例先减小后增大,胸径(地径)与断枝少个体的比例呈极显著正相关(P0.01),与严重断枝或断梢和折断个体的比例呈极显著负相关(P0.01);树木的损伤比例随树高增大而降低,但断枝多、断梢等损伤程度高的比例有增加的趋势。矮树主要为压弯和折断,中、高树主要为断枝;树冠重叠度与树木中度受损呈显著正相关(r=0.824,P0.01),重叠度低的树木易发生压弯、折断和倒伏,重叠度高的易发生断枝。受损比例高于40%的6个树种间的受损指数差异显著(P0.05),香樟(Cinnamomum camphora)的受损指数最高(ID=0.42),与其他5个树种之间均存在显著差异。该研究对绿化树种的选择及突发暴雪灾害中树种的管理和保护具有一定参考意义。     

太原市空气的SO2污染及树木的吸收净化

研究了太原市空气中SO2浓度的年际、月份和垂直变化规律．实验结果表明，夏季和秋季SO2浓度低，污染较轻，春季和冬季的SO2浓度大，污染重，沿垂直方向在1m高处的SO2浓度最大，7m高的位置SO2浓度明显降低，20m处更低．测试了银杏、白蜡和国槐3种绿化树种的枝条韧皮部和叶片的含硫量，其逐月变化规律说明这些树种对城市空气中的SO2具有很强的吸收能力，是城市绿化和净化污染的优良树种．结合树木的叶片容量和含硫量的关系，评价了它们净化污染的效益，结合SO2垂直变化规律提出立体绿化配置．图2表3参7     

衡阳市区主要园林树木害虫的种类与危害研究

在调查、采集和饲养的基础上,共鉴定出衡阳市主要园林树木害虫84种.并分析了衡阳市区主要园林树木害虫的发生危害特点,提出了相应的防治策略.     

天津市区景观生态及物种多样性

天津市区的景观生态系统,由于受地域、气候等因素的限制,品种比较单一,春、夏、秋三季缺乏彩色,冬季缺乏绿色。为了改变这种现状,可以结合春季干旱、夏季炎热、冬季寒冷、降水量少且不均匀的气候特点,根据乔灌草混合立体栽种的绿化美化原则,因地制宜地引进一些适合本地环境和气候条件的具有"彩色"、"长绿"和"香味"特点的美化绿化树种,和本地的传统树种搭配种植,达到优化城市生态系统、丰富植物种群和提高观赏效果的目的。根据各种植物对光的补偿点不同的原理,最大限度地创造绿量,让城市生态环境向良性循环的方向发展。     

A multi-scale examination of stopover habitat use by birds

Most of our understanding of habitat use by migrating land birds comes from studies conducted at single, small spatial scales, which may overemphasize the importance of intrinsic habitat factors, such as food availability, in shaping migrant distributions. We believe that a multi-scale approach is essential to assess the influence of factors that control en route habitat use. We determined the relative importance of eight variables, each operating at a habitat-patch, landscape, or regional spatial scale, in explaining the differential use of hardwood forests by Nearctic-Neotropical land birds during migration. We estimated bird densities through transect surveys at sites near the Mississippi coast during spring and autumn migration within landscapes with variable amounts of hardwood forest cover. At a regional scale, migrant density increased with proximity to the coast, which was of moderate importance in explaining bird densities, probably due to constraints imposed on migrants when negotiating the Gulf of Mexico. The amount of hardwood forest cover at a landscape scale was positively correlated with arthropod abundance and had the greatest importance in explaining densities of all migrants, as a group, during spring, and of insectivorous migrants during autumn. Among landscape scales ranging from 500 m to 10 km radius, the densities of migrants were, on average, most strongly and positively related to the amount of hardwood forest cover within a 5 km radius. We suggest that hardwood forest cover at this scale may be an indicator of habitat quality that migrants use as a cue when landing at the end of a migratory flight. At the patch scale, direct measures of arthropod abundance and plant community composition were also important in explaining migrant densities, whereas habitat structure was of little importance. The relative amount of fleshy-fruited trees was positively related and was the most important variable explaining frugivorous migrant density during autumn. Although constraints extrinsic to habitat had a moderate role in explaining migrant distributions, our results are consistent with the view that food availability is the ultimate factor shaping the distributions of birds during stopover.     

A Landscape Approach to Biodiversity Conservation of Sacred Groves in the Western Ghats of India

Abstract:  Although sacred groves are important for conservation in India, the landscape that surrounds them has a vital influence on biodiversity within them. Research has focused on tree diversity inside these forest patches. In a coffee-growing region of the Western Ghats, however, landscape outside sacred groves is also tree covered because planters have retained native trees to provide shade for coffee plants. We examined the diversity of trees, birds, and macrofungi at 58 sites—10 forest-reserve sites, 25 sacred groves, and 23 coffee plantations— in Kodagu district. We measured landscape composition and configuration around each site with a geographic information system. To identify factors associated with diversity we constructed multivariate models by using a decision-tree technique. The conventional measures of landscape fragmentation such as patch size did not influence species richness. Distance of sacred groves from the forest reserve had a weak influence. The measures of landscape structure (e.g., tree cover in the surroundings) and stand structure (e.g., variability in canopy height) contributed to the variation in species richness explained by multivariate models. We suggest that biodiversity present within sacred groves has been influenced by native tree cover in the surrounding landscape. To conserve this biodiversity the integrity of the tree-covered landscape matrix will need to be conserved.     

Host plant quality and local adaptation determine the distribution of a gall-forming herbivore

Herein we report results of transplant experiments that link variation in host plant quality to herbivore fitness at the local scale (among adjacent plants) with the process of local (demic) adaptation at the landscape scale to explain the observed distribution of the specialist gall former Belonocnema treatae (Hymenoptera: Cynipidae) within populations of its host plant, Quercus fusiformis. Field surveys show that leaf gall densities vary by orders of magnitude among adjacent trees and that high-gall-density trees are both rare (< 5%) and patchily distributed. B. treatae from each of five high-gall-density trees were reared on (1) the four nearest low-gall-density trees, (2) the four alternative high-gall-density trees, and (3) their natal trees (control). Each treatment (source X rearing site) was replicated three times. Nine components of performance that sequentially contribute to fitness were evaluated with over 21000 galls censused across the 25 experimental trees. When reared on their natal trees and compared with low-gall-density neighbors, transplanted gall formers had higher gall initiation success (P < 0.05), produced more (P < 0.001) and larger galls (P < 0.001), and produced a higher proportion of galls that exceeded the threshold size for natural enemy avoidance (P < 0.05). Comparison of gall-former performance on natal vs. alternative high-gall-density trees demonstrated significant (P < 0.001) differences in six performance measures with five differing in the direction predicted by the hypothesis of local adaptation. Overall, these linked experiments document direct and indirect effects of host plant variation on gall-former performance and demonstrate convincingly that (1) high-gall-density trees equate to high-quality trees that are surrounded by trees of relatively lower quality to the herbivore and (2) gall-former populations have become locally adapted to individual trees.     

Defining patch mosaic functional types to predict invasion patterns in a forest landscape.

Alien plant invasions contribute significantly to global changes by often affecting biodiversity and ecosystem processes. Operational methods for identifying landscape attributes that promote or constrain plant invasions are urgently needed to predict their future spread and manage them efficiently. We combined landscape and functional ecology concepts to define patch mosaic functional types (PMFTs) as groups of cells showing the same response to a plant invasion in a heterogeneous forest landscape. The invasion of a European temperate forest by the American black cherry (Prunus serotina) has been chosen as a case study. A set of variables was collected, mapped using a Geographic Information System, and analyzed with multivariate analyses to correlate landscape traits with Prunus serotina abundance in each cell of a grid overlaid on the forest. A risk index was derived and mapped for three invasion levels: seedling colonization, tree establishment, and ecosystem invasion. Five PMFTs were identified and characterized by a set of traits related to soil properties, land use, disturbance, and invasion history. Scots pine plantations on podzols were the most invasible, while cells dominated by hydromorphic or calcareous soils were the most resistant. Most colonized patch mosaics provided suitable conditions for future establishment and invasion. Being strongly spatially connected, suitable patches provide corridors for Prunus serotina to colonize new parts of the forest. Conversely, the most resistant PMFTs were spatially agglomerated in the south of the forest and could act as a barrier. Colonization, establishment, and invasion risk maps were finally obtained by combining partial risks associated with each landscape trait at the cell scale. Within a heterogeneous landscape, we defined and organized PMFTs into a hierarchy, according to their associated risk for colonization, establishment, or invasion by a given invasive species. Each hierarchical level should be associated with a management strategy aiming at reducing one or more partial risk. Monitoring safe areas, extending cutting rotations, harvesting recently colonized stands tree by tree, promoting a multilayered understory vegetation, cutting down reproducing alien trees, favoring shade-tolerant, fast-growing, native tree species, removing alien trees at the leading edge, and proposing soil enrichment or irrigation in heavily invaded areas are recommended.     

Rain forest fragmentation and the proliferation of successional trees

The effects of habitat fragmentation on diverse tropical tree communities are poorly understood. Over a 20-year period we monitored the density of 52 tree species in nine predominantly successional genera (Annona, Bellucia, Cecropia, Croton, Goupia, Jacaranda, Miconia, Pourouma, Vismia) in fragmented and continuous Amazonian forests. We also evaluated the relative importance of soil, topographic, forest dynamic, and landscape variables in explaining the abundance and species composition of successional trees. Data were collected within 66 permanent 1-ha plots within a large (approximately 1000 km2) experimental landscape, with forest fragments ranging from 1 to 100 ha in area. Prior to forest fragmentation, successional trees were uncommon, typically comprising 2-3% of all trees (> or =10 cm diameter at breast height [1.3 m above the ground surface]) in each plot. Following fragmentation, the density and basal area of successional trees increased rapidly. By 13-17 years after fragmentation, successional trees had tripled in abundance in fragment and edge plots and constituted more than a quarter of all trees in some plots. Fragment age had strong, positive effects on the density and basal area of successional trees, with no indication of a plateau in these variables, suggesting that successional species could become even more abundant in fragments over time. Nonetheless, the 52 species differed greatly in their responses to fragmentation and forest edges. Some disturbance-favoring pioneers (e.g., Cecropia sciadophylla, Vismia guianensis, V. amazonica, V. bemerguii, Miconia cf. crassinervia) increased by >1000% in density on edge plots, whereas over a third (19 of 52) of all species remained constant or declined in numbers. Species responses to fragmentation were effectively predicted by their median growth rate in nearby intact forest, suggesting that faster-growing species have a strong advantage in forest fragments. An ordination analysis revealed three main gradients in successional-species composition across our study area. Species gradients were most strongly influenced by the standlevel rate of tree mortality on each plot and by the number of nearby forest edges. Species-composition also varied significantly among different cattle ranches, which differed in their surrounding matrices and disturbance histories. These same variables were also the best predictors of total successional-tree abundance and species richness. Successional-tree assemblages in fragment interior plots (>150 m from edge), which are subjected to fragment area effects but not edge effects, did not differ significantly from those in intact forest, indicating that area effects per se had little influence on successional trees. Soils and topography also had little discernable effect on these species. Collectively, our results indicate that successional-tree species proliferate rapidly in fragmented Amazonian forests, largely as a result of chronically elevated tree mortality near forest edges and possibly an increased seed rain from successional plants growing in nearby degraded habitats. The proliferation of fast-growing successional trees and correlated decline of old-growth trees will have important effects on species composition, forest dynamics, carbon storage, and nutrient cycling in fragmented forests.     

Ecological Trap for Desert Lizards Caused by Anthropogenic Changes in Habitat Structure that Favor Predator Activity

Abstract: Anthropogenic habitat perturbation is a major cause of population decline. A standard practice managers use to protect populations is to leave portions of natural habitat intact. We describe a case study in which, despite the use of this practice, the critically endangered lizard Acanthodactylus beershebensis was locally extirpated from both manipulated and natural patches within a mosaic landscape of an afforestation project. We hypothesized that increased structural complexity in planted patches favors avian predator activity and makes these patches less suitable for lizards due to a heightened risk of predation. Spatial rarity of natural perches (e.g., trees) in arid scrublands may hinder the ability of desert lizards to associate perches with low‐quality habitat, turning planted patches into ecological traps for such species. We erected artificial trees in a structurally simple arid habitat (similar to the way trees were planted in the afforestation project) and compared lizard population dynamics in plots with these structures and without. Survival of lizards in the plots with artificial trees was lower than survival in plots without artificial trees. Hatchlings dispersed into plots with artificial trees in a manner that indicated they perceived the quality of these plots as similar to the surrounding, unmanipulated landscape. Our results showed that local anthropogenic changes in habitat structure that seem relatively harmless may have a considerable negative effect beyond the immediate area of the perturbation because the disturbed habitat may become an ecological trap.     

Cover Caption

Cover: Tropical pastures present multiple barriers to tree regeneration, but canopies of relict trees can serve as repositories of viable seeds deposited when the forest was intact. When mats of arboreal soil fall to the pasture floor, their seedbank can contribute to forest regeneration, their seeds serving as "time capsules" from the primary forest. The lush epiphytic ferns ( Polypodium spp. ) and accompanying arboreal soil on this mature live oak are viewed from above in a subtropical landscape of Florida. Photo by John T. Longino. See pages 1117–1126.     

Regionale Klimatrends mit Hilfe der phänologischen Uhr, dargestellt am Beispiel Rheinland-Pfalz

Aims and Scope

Over recent decades, the climate has changed. Up to now this statement has been made predominantly for the global and/or continental area. What, however, is the situation regarding the climatic trend at the regional scale? Is it already possible to show effects of a climate change in small-scale landscape structures? These questions were addressed looking at the example of the situation in the federal state of Rhineland-Palatinate (Germany).

Methods

Phenological data of plants of the last 50 years from a total of 386 stations of the German Weather Service (DWD) were evaluated. The timing of the different plant phases, beginning of the foliation and plant senescence in autumn, flowering and the first ripening of the fruits had to be registered for different agricultural crops, wild plants, ornamental woods as well as fruit trees. The analysed data material was used to develop the threefold phenological clock (DPU).

Results

Summarising the findings of the DPU for the 15 evaluated nature districts of Rhineland-Palatinate according to individual seasons, which were defined in generic terms as spring, summer, autumn and winter, a tendency of a prematuring of the spring, a prolongation of the autumn as well as a shortening of the winter is evident. From a regional point of view, on the other hand, in individual nature districts such as the ‘Westerwald’ and the ‘Bergisch-Sauerländische Gebirge’, winter seasons are getting longer. Thus the effects of a climate change can differ considerably from region to region.

Outlook

The regionally quite different changes of the climatic situation in Rhineland-Palatinate will not remain without an effect on the ecosystems of this federal state. The currently existing biocoenosis will therefore change. The consequences for forestry, agriculture and nature conservation are of special interest in this context.