Impacts of forest management on liana diversity and community structure in a tropical forest in Ghana: implications for conservation

We studied the impacts of liana cutting as a forest management tool on liana diversity(species richness,Shannon diversity index) and community structure(diameter distribution, basal area, species dominance) in the Asenanyo Forest Reserve, Ghana. Two types of silviculturally treated forests were studied: Logging treated(LT)and Tropical Shelterwood System(TSS) treated forests. An untreated primary forest was included as a control, resulting in three forest management systems. Lianas with diameter C2 cm were identified in ten 40 9 40 m2 plots within each management system. Liana cutting significantly reduced liana species richness, Shannon diversity index, and basal area in the LT forest after two decades.However, liana species richness and basal area werecomparable in the TSS treated and untreated forests, indicating significant recovery in the former after over six decades. S?rensen similarity index of liana species composition between the untreated forest and each of the treated forests was moderate. Our findings suggest that liana cutting most likely influenced the dominance of some liana species. In view of the adverse impact of blanket liana cutting on liana diversity, selective liana cutting is recommended as a means of controlling liana numbers while maintaining liana diversity.     

海南霸王岭天然次生林边缘效应下木质藤本的变化

选择海南岛霸王岭天然恢复60年的次生林样地中形成年限为17和13年的边缘,分别设置4条10m×100m的样带,研究边缘效应对木质藤本多度、丰富度、胸高断面积、径级结构和攀援方式的影响。结果表明:8条样带中,记录木质藤本植物89种3252株;2种边缘中,木质藤本多度都随距边缘距离的增加显著降低,木质藤本胸高断面积未产生显著变化,木质藤本丰富度只在17年边缘中随距离增加而降低;在13年边缘中,随距边缘距离的增加,胸径大于1cm的木质藤本个体比例有所增加,而17年边缘中藤本的径级结构相对稳定;距边缘不同距离间,不同攀援方式木质藤本的个体比例存在显著差异,2种边缘中主茎缠绕类藤本均占优势。边缘效应对木质藤本群落结构的影响随距边缘距离的增加而减弱,影响深度随边缘形成年限的增加而增加,在17年边缘中影响深度为40～50m,在13年边缘中约为10m。     

The influence of reproductive traits on liana abundance 10 years after conventional and reduced-impacts logging in the eastern Brazilian Amazon

Balancing timber production and conservation in tropical forests requires an understanding of the impacts of silvicultural manipulations on specific groups of organisms. Lianas are characteristic of many tropical forests, where they contribute to species diversity, ecosystem functioning, and biomass. However, lianas can also impede timber production by increasing logging damage and slowing tree growth. Cutting lianas prior to logging can mitigate the negative effects, but may adversely affect a forest's value for conservation. To evaluate the effects of forest management activities on lianas, this study assessed the impacts of logging, both with and without pre-logging liana cutting, on the relative abundance and population structure of five species of lianas that differed in primary reproductive strategies.Inventories of the five study species were conducted 10 years following logging in 4.4 ha plots in three adjacent treatment areas: (1) an old-growth forest reserve, (2) a selectively-logged forest that used conventional practices for the region, and (3) a forest that was logged using reduced-impact logging (RIL) techniques including complete liana cutting prior to logging. Liana species responses to logging varied according to their primary modes of reproduction. Croton ascendens, a pioneer species with a persistent seed bank, had a higher abundance in the two logging treatments relative to the old-growth forest, while Serjania caracasana, an early successional species lacking a persistent seed bank, showed abundant regeneration following conventional logging but negligible regeneration following RIL. In contrast, Acacia multipinnata, also an early successional species, showed abundant regeneration following RIL owing to the sprouting of persistent prostrate stems present on the forest floor prior to logging. In both logged areas, Bauhinia guianensis recruited abundant climbing stems from self-supporting seedlings that were present prior to logging, but it showed greatly reduced seedling density following RIL. By sprouting profusely from both fallen stems and stumps, Memora schomburgkii recruited abundant small-diameter climbing stems in both of the logging treatments. The results of this study demonstrate that there are interspecific differences in liana responses to different types of logging and that knowing species’ primary modes of reproduction is a valuable first step toward predicting those responses.     

Patterns of liana diversity in tropical evergreen forests of peninsular India

The quantitative liana inventories made in five peninsular Indian independent forest sites, distributed in the Western Ghats, Eastern Ghats and on the Coromandel coast, were examined particularly with reference to site altitude and forest stature. Liana diversity totaled 148 species in 101 genera of 47 families, in a total sample of 47 ha. The coefficient of variability in species distribution among the five sites was used to identify an oligarchy in liana species by taking 55 abundant species from the species pool. Ordination analysis, based on presence–absence as well as relative density of liana species indicated a geographical differentiation among the five sites in both the ordinations with respect to site altitude. Liana density (stems>1.6 cm diameter) decreased with increasing altitude, whereas richness was highest at intermediate elevations. The mean liana density across the forest sites showed a weak negative correlation with forest stature. The lianas encountered in the five study sites fell under six climber types, of which twining was the chief climbing mechanism, both in terms of species diversity and density, and tendril climbers were more abundant in dry evergreen forests than in the wet evergreen forests. In liana diaspore dispersal modes, the majority of evergreen forest species possessed animal dispersal guilds, whereas wind-dispersal was prevalent in semi-evergreen and dry evergreen forests.     

海南霸王岭山地原始林与伐后林中木质藤本与支持木的多样性及其相互关系

研究海南霸王岭热带山地雨林原始林与伐后林的物种多样性及木质藤本与支持木的关系。结果表明:原始林中树木的物种丰富度和多度低于伐后林(P<0.05),而木质藤本的物种丰富度和多度在原始林与伐后林间无显著差异;原始林中树木的平均附藤率和平均每木附藤数均高于伐后林(P<0.05),而平均每藤攀附支持木个体数表现为伐后林高于原始林(P<0.05);在原始林中树木胸径与平均每木藤本数间呈显著的三次函数关系,伐后林中树木胸径与平均每木藤本数间呈显著的幂函数关系;树木高度与平均每木藤本数在2林型中均呈显著的三次函数关系。     

Liana species richness,abundance and relationship with trees in the Bobiri forest reserve,Ghana: Impact of management systems

Forest management practices which may represent various forms of disturbance regimes could influence liana species richness, abundance and relationship with their hosts. The study sought to determine the impacts of three management systems, namely, the Selection, Tropical Shelterwood and Post Exploitation Systems (SS, TSS and PES respectively) on liana species richness, abundance and relationship with trees in the Bobiri forest reserve, Ghana. Lianas with dbh ≥ 2 cm found on trees with dbh ≥ 10 cm were enumerated in 1 ha plot each in the SS, TSS and PES. All trees (dbh ≥ 10 cm) within the plots that did not carry lianas were also enumerated. A total of 640 liana individuals belonging to 27 species, 22 genera and 13 families were identified in the management systems. Griffonia simplicifolia (Vahl ex DC.) Baill., Motandra guineensis (Thonn.) A.DC. and Calycobolus africanus (G.Don) Heine were the abundant species in all the management systems. Unlike in SS, lianas in the TSS and PES were dominated by a few species. Larger diameter lianas were more abundant in the PES (32%) compared with the SS (18.3%) and the PES (13.1%). Liana diversity (H′) (species richness and abundance) was quantitatively higher in the SS (2.8) than the TSS (2.2) and the PES (2.0). The numbers of lianas carried by tree species differed significantly in the management systems (p < 0.001 each). Liana infestation in the forest was high. The level of liana infestation did not reflect the extent of liana load per tree in the management systems. Larger trees carried significantly more liana individuals than smaller trees in the PES (p = 0.019, r² = 0.15). There was a positive significant relationship between host dbh and liana dbh in the PES (p < 0.001, r² = 0.23) and TSS (p = 0.024, r² = 0.11). Tree diversity appeared to have influenced liana species richness and abundance.     

3种改造方式对深圳龙岗区生态风景林植物多样性影响

通过样方调查,对深圳市龙岗区生态风景林中的未改造低效林、天然次生林及3种改造林分（林下套种林、皆伐林、疏伐林）的植物多样性进行对比分析,了解不同改造措施对林分植物多样性的影响.结果表明：各类型林分的物种丰富度排序为林下套种林＞皆伐林=天然林＞疏伐林＞未改造林;经过3种方式改造后林分乔木层的Shannon-Wiener指数、Simpson指数、Pielou指数皆高于未改造低效林和天然次生林,其中Shannon-Wiener指数和Pielou指数均以林下套种林最高,其次是皆伐林,Simpson指数以皆伐林最高,林下套种林次之;改造后林分灌草层的物种多样性指数均高于未改造林,其中皆伐林物种多样性指数均高于天然次生林.综合比较疏伐、皆伐和林下套种3种改造方式对生态风景林群落植物多样性的影响,疏伐是较适宜本地区生态风景林改造的措施.     

Liana habitat and host preferences in northern temperate forests

Lianas and other climbers are important ecological and structural components of forest communities. Like other plants, their abundance in a given habitat depends on a variety of factors, such as light, soil moisture and nutrients. However, since lianas require external support, host tree characteristics also influence their distribution. Lianas are conspicuous life forms in tropical regions, but in temperate areas, where they are less prominent, little is known about factors that control their distributions in these forests. We surveyed the climbing plant species in 20 mature (100 years and greater) forested habitats in the Midwest USA at a variety of levels from simple presence/absence, to ground layer abundances, to those species that had ascended trees. We also examined attributes of the tree species with climbers attached to them. Using cluster analysis, we distinguished five different tree communities in our survey locations. We determined that 25% of the trees we surveyed had one or more lianas attached to it, with Parthenocissus quinquefolia (Virginia creeper) the most common climbing species encountered. Canopy cover and soil attributes both influenced climber species presence/absence and ground layer climber abundance. The proportion of liana species of a given climbing type (roots, stem twiner, tendril climber) was significantly related to the DBH of the host tree, with more root climbers and fewer stem and tendril climbers on large trees. In general, the DBH of climbing lianas had a significant positive relationship to the DBH of the host tree; however this varied by the identity of the liana and the tree species. The greater the DBH of the host tree, the higher the probability that it was colonized by one or more lianas, with tree species such as Pinus banksiana (jack pine) and Quercus alba (white oak) being more susceptible to liana colonization than others. Finally, some liana species such as Celastrus scandens (American bittersweet) showed a preference for certain tree species (i.e., P. banksiana) as hosts. The information obtained about the relationship between the tree and climber community in this study provides insight into some of the factors that influence liana distributions in understudied temperate forest habitats and how lianas contribute to the structure of these mature forests. In addition, these data can provide a point of comparison to other liana communities in both temperate and tropical regions.     

Factors controlling the abundance of lianas along an altitudinal transect of tropical forests in Ecuador

In the light of putatively increasing liana abundances in present-day tropical forests and a persistent lack of understanding of liana abundance patterns and the responsible factors, we attempt to identify the key factors controlling liana abundance along an altitudinal transect in NE Ecuador. At four elevational levels (500, 1000, 1500, and 2000 m), each represented by 10 plots of 400 m², the abundance and diameters of all lianas (dbh ≥ 1 cm) and trees (dbh ≥ 10 cm) were recorded in old-growth forest stands in the Sumaco Biosphere Reserve (SBR). Results were analysed with available data on soil chemical properties and canopy structure.     

哀牢山湿性常绿阔叶林木质藤本植物的物种多样性及其与支柱木的关系

分别在哀牢山湿性常绿阔叶林沟谷和坡面调查了10个20m×50m的样地,研究哀牢山湿性常绿阔叶林木质藤本植物的物种多样性及其与支柱木的关系。结果表明:研究区共记录到DBH≥1cm的木质藤本植物402株(隶属于23种21属16科)和DBH≥10cm的林木1522株(隶属于47种30属15科);与其他亚热带森林比较,该森林中木质藤本植物物种较为丰富但多度较低;藤本植物的物种丰富度、密度和基面积在沟谷显著高于坡面,而林木的差异性不显著;木质藤本植物在支柱木上呈集群分布,并且不同种支柱木被藤本植物攀援的百分比间存在显著的差异(P0.001),说明藤本植物的攀援对支柱木具有选择性;云南越桔、薄叶马银花和景东冬青等树种因其树皮光滑而不易被藤本植物攀援,而腾冲栲、七裂槭、山矾和多花山矾等则易于被藤本植物攀援;大径级支柱木被藤本植物攀援的比率高于小径级支柱木;茎缠绕和钩刺攀援藤本的胸径与支柱木胸径极显著相关(P0.001),根攀援和卷须攀援藤本的胸径与支柱木胸径相关性不显著(P0.05)。     

Impact of logging on tree,liana and herb assemblages in a Bornean forest

In the present study, the impact of logging was assessed on the forest structure, richness, and composition of trees, lianas, and ground herbs in Indonesian Borneo. There were no significant differences in tree height, diameter, basal area, or abundance between unlogged and logged forest. Liana abundance was higher in logged than unlogged forest, but the difference was marginally nonsignificant. There was also no significant difference in the percentage cover of ground herbs. Tree species richness was similar between unlogged and logged forest, while liana species richness was higher in logged forest and herb species richness between unlogged forest. Tree and liana compositions differed significantly between unlogged and logged forest, but logging explained only a small part (<7%) of the variance in composition. In contrast to trees and lianas, ground herb composition did not differ significantly between unlogged and logged forest. Our findings indicate that the modest extraction intensity practiced did not have a severely adverse impact on forest structure or plant composition. This highlights the important role that logged forests may play in conserving biodiversity and the need to protect these forests from further disturbance.     

昆明地区野生藤蔓植物资源调查

依据野外调查和有关文献资料,对昆明地区的野生藤蔓植物资源进行了调查.结果表明,该区野生藤蔓植物共有64科180属394种,生活习性以木本稍占优势.其中攀援植物群共305种,匍匐植物群共89种.攀援植物群中缠绕类有171种,卷攀类有85种,吸附类有19种,棘刺类有28种,依附类有2种.观赏习性按花色以白色花系最多,按果色以红色果实最多.对昆明地区的野生藤蔓植物资源开发利用提出了4点建议.     

Effects of human disturbances and plant invasion on liana community structure and relationship with trees in the Tinte Bepo forest reserve,Ghana

There are conflicting reports on the role of disturbances in maintaining liana community structure, and in determining their relationship with trees. The effects of plant invasion on these attributes of lianas are not known. The study investigated the effects of human disturbances and plant invasion on liana community structure and relationship with trees in the Tinte Bepo forest reserve, Ghana, in three distinct forest types to reflect both human disturbances and invasion: Undisturbed, Disturbed-Invaded and Disturbed Forests (UF, DIF and DF respectively). Trees ≥10 cm dbh were identified and their dbh measured in two 0.25 ha plots in each forest type. The trees were examined for the presence of lianas (≥2 cm dbh) and their dbh measured. A total of 380 lianas ≥2 cm dbh belonging to 20 genera and 12 families were identified in the 1.5 ha forest. Twelve liana species were unique to the DIF suggesting the probable positive influence of plant invasion on their colonisation. Liana density differed significantly across the forest types (df = 2, p = 0.043) with the UF recording the greatest number. The mean liana stem diameter and basal area were greater in the DF. Large diameter lianas were absent in the UF. Tree density and number of trees hosting lianas were greater in the UF followed by the DIF and DF. Liana infestation was generally high with 90% in the DF, 88.2% in the UF, and 85.7% in the DIF. Both liana load per tree species and mean liana load per infested tree were highest in the UF followed by the DIF and then the DF. Liana density was highly dependent on tree density in all the forest types (df = 1, r² = 0.50, p = 0.007; df = 1, r² = 0.99, p = 0.000 and df = 1, r² = 0.72, p = 0.000 in the UF, DIF and DF respectively). There was a significant positive relationship between liana dbh and host dbh in the UF (df = 1, r² = 0.096, p = 0.000), DIF (df = 1, r² = 0.11, p = 0.000) and DF (df = 1, r² = 0.16, p = 0.008). There was no significant relationship between host dbh and liana loads in all the forest types.     

不同强度间伐对长白山天然林林下植物多样性的影响

对吉林森工集团松江河林业局辖区内的阔叶红松林、杂木林和杨桦林采取30%～40%（T1）、20%（T2）株数强度的均匀间伐处理,以不间伐处理为对照（CK）,对间伐2 a后林下植物木本、草本植物进行调查,采用Simpson、Shannon-Wiener多样性指数和Pielou均匀度指数进行植物多样性分析,探讨不同强度间伐对3个林型林下植物多样性的影响。研究结果表明：T1间伐后3个林型的物种丰富度均有增加（杂木林木本植物例外）,T2间伐后杨桦林木本植物丰富度降低,草本植物丰富度增加。两种间伐处理均增加阔叶红松林木本植物多样性,T1处理尤为明显。T1处理增加杂木林和杨桦林木本植物多样性,而T2间伐处理有较弱的降低作用。两种间伐处理均降低阔叶红松林和杂木林草本植物多样性,与强度无明显关系。随着间伐强度的增加杨桦林草本植物多样性增大。在长白山天然林中,较大间伐强度T1（30%～40%）能够有效提高植物多样性。     

Liana abundance in a Puerto Rican forest

Liana (woody vine) abundance varies among tropical forests and is often high in disturbed forests. In two areas of subtropical wet forest in Puerto Rico, El Verde and Bisley, we recorded the density of liana stems ≥1 cm dbh, and the percent of tree crowns (trees ≥10 cm dbh) that lianas infested. Both study areas have been disturbed by hurricanes several times in the past century; however, sample plots in each area were divided between plots that were less disturbed and those that were more disturbed, by both hurricanes and humans. The mean density and basal area of liana stems at El Verde were significantly higher in the less disturbed plots than in the more disturbed plots. The percent tree crown infested by lianas was higher on certain tree species and on larger trees, both of which characterized the less disturbed forest. Results at Bisley were similar to those at El Verde. Liana density and tree crown infestation in these Puerto Rican forests were low compared with most other tropical forests, contrasting especially with high values in other disturbed forests. Liana abundance varies among forests for complex reasons, including differences in disturbance, biogeography, seasonality, and tree host features.     

Assessing rates of forest change and fragmentation in Alabama,USA, using the vegetation change tracker model

Forest change is of great concern for land use decision makers and conservation communities. Quantitative and spatial forest change information is critical for addressing many pressing issues, including global climate change, carbon budgets, and sustainability. In this study, our analysis focuses on the differences in geospatial patterns and their changes between federal forests and nonfederal forests in Alabama over the time period 1987–2005, by interpreting 163 Landsat Thematic Mapper (TM) scenes using a vegetation change tracker (VCT) model. Our analysis revealed that for the most part of 1990 s and between 2000 and 2005, Alabama lost about 2% of its forest on an annual basis due to disturbances, but much of the losses were balanced by forest regeneration from previous disturbances. The disturbance maps revealed that federal forests were reasonably well protected, with the fragmentation remaining relatively stable over time. In contrast, nonfederal forests, which are predominant in area share (about 95%), were heavily disturbed, clearly demonstrating decreasing levels of fragmentation during the time period 1987–1993 giving way to a subsequent accelerating fragmentation during the time period 1994–2005. Additionally, the identification of the statistical relationships between forest fragmentation status and forest loss rate and forest net change rate in relation to land ownership implied the distinct differences in forest cutting rate and cutting patterns between federal forests and nonfederal forests. The forest spatial change information derived from the model has provided valuable insights regarding regional forest management practices and disturbance regimes, which are closely associated with regional economics and environmental concerns.     

粤西次生针阔混交群落的林下植被物种组成与多样性研究

季风常绿阔叶林是南亚热带的地带性植被类型,经采伐干扰和人工造林后形成大面积的次生林。参照CTFS样地建设技术规范,于2006年在广东粤西马尾松针阔次生林建立2 hm2固定监测样地。在对样地进行调查的基础上,分析了林下植被的物种组成与多样性。结果表明：（1）样地共有维管束植物207种,隶属于79科144属,数量优势科为茜草科、大戟科、樟科、番荔枝科、紫金牛科、禾本科和蔷薇科;单种属植物较多（101属）,占总属数的70.14%。林下植物泛热带和热带亚洲成分占绝对优势,具有南亚热带向中亚热带过渡的特征。（2）物种的丰富度指数表现出乔木幼苗〉灌木层〉藤本层〉草本层;Shannon-Wiener指数表现出乔木幼苗〉藤本层〉灌木层〉草本层;Simpson指数则为乔木幼苗〉藤本层〉草本层〉灌木层;均匀度指数为乔木幼苗〉藤本层〉灌木层〉草本层。     

Effects of fire disturbance on bird communities and species of mountain Serrano forest in central Argentina

In central Argentina, Serrano forest has a long history of fire disturbance; however, the impact of fire on avifauna remains unknown. We compared the avian–habitat relationships in forest patches with low, moderate, and high fire regimes using a community-level (species richness, abundance, ordination and guilds) and species-level (indicator species analysis) approach. In patches under each fire condition, we recorded bird community composition, richness and abundance, and different vegetation structure variables. The site under high-severity fire regime was structurally poor and had been converted from original forest to dense grassland. There, diversity of bird community was low, retaining approximately 30 % of the species present in the least impacted site. Avian assemblage was dominated by generalist and open area birds. Guilds were underrepresented, showing an important reduction of foliage granivorous, nectarivorous, omnivores, and foliage and bark insectivorous, and absence of fly-catchers. Moreover, low abundance of forest understory, midstory, and canopy species and of birds belonging to open and closed nesting guilds was detected. By contrast, under low and moderate-severity fire regimes highest bird diversity as well as highest representativeness of most guilds was observed. Forest bird species were strongly associated with low fire disturbance, whereas moderate fire disturbance was characterized by the presence of forest and generalist species. Given the critical conservation status of Serrano forest in Córdoba, Argentina, habitat restoration and protection of forest relicts could be suitable measures to promote avifauna preservation.     

兴安落叶松林分空间分布格局的研究

通过样地调查,对内蒙古大兴安岭北部兴安落叶松3种森林类型(原始林、渐伐林、皆伐更新林)的林分空间分布格局进行了研究。结果表明:3种林分的分布格局均为聚集分布,但聚集程度存在差异,聚集强度依次为皆伐更新林>原始林>渐伐林。并提出了兴安落叶松合理经营管理的建议。     

Impacts of temperate lianas on tree growth in young deciduous forests

Lianas are often overlooked in temperate ecological studies even though they are important components of forest communities. While lianas have been shown to damage tropical canopy trees and reduce the growth of juvenile trees, the impact of lianas on canopy tree growth in temperate systems is largely unknown. Growth of trees ≥8 cm dbh was examined over a 9-year period within 50-year old post-agricultural secondary forests in the Piedmont region of New Jersey, USA. Five lianas, Celastrus orbiculatus, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis species, occurred throughout the forest. Total liana basal area, number of stems, and percent cover within host trees were evaluated to assess liana burdens on 606 previously censused trees. These data were related to tree growth to assess liana impacts. Forest trees were separated based on their dominance in the canopy to determine whether lianas had the potential to influence forest composition. In general, lianas in the forests were fairly abundant, with 68% of the trees having at least one liana present. On average, each tree supported 9.7 cm² of liana basal area and 23% of the canopy was covered by lianas. Most of the variation in tree growth was related to the dominance of trees within the canopy, with canopy dominant and co-dominant trees growing 2.5× more than suppressed trees. Liana basal area and number of lianas stems were not related to tree growth, but liana canopy cover decreased tree growth. However, not all trees were equally affected as canopy cover of lianas only reduced growth in dominant and co-dominant trees. Lianas were most influential on host tree growth in unsuppressed trees when occupying a majority of the canopy, only a minority of forest trees. This suppression was not related to differential liana colonization of canopy trees as all canopy classes supported equivalent liana burdens. Though lianas impacted only a minority of the trees in this system, some liana species, C. orbiculatus and Vitis spp., are still increasing and may pose future risks to forest growth and development.