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This paper explores the significance of ecosystem functions in maintaining the health and balance of ecological systems, particularly in the context of planning, managing, and maintaining trees in landscape settings. It emphasises the multifaceted relationship between humans and trees, encompassing cultural, ecological, economic, and emotional connections, and underscores the value of traditional ecological knowledge alongside empirical science. By combining these two ways of knowing, along with social science insights into human health and well-being, future landscapes can be crafted to be sustainable, diverse, and functional. As urbanisation continues to shape landscapes globally, urban planners face the challenge of managing rapidly changing environments. Urban forestry and arboriculture have emerged to address these challenges, aiming to enhance environmental quality and human well-being. The concept of Nature-based Solutions (NbS) has gained traction, recognising the importance of integrating natural systems into urban planning to address environmental challenges while preserving functional ecosystems. This paper advocates for an enhanced understanding of tree and human ecology to navigate the complex relations between trees, people, and their environments. It calls for interdisciplinary collaboration, research, and education to inform policy, assess environmental impacts, and widen approaches to ecosystem management. By monitoring ecosystem health and collaborating across disciplines, arboriculturists and urban foresters can shape resilient practices for tree conservation and sustainable urban development. In conclusion, integrating tree ecology into urban planning and management practices is essential for ensuring the health, resilience, and sustainability of tree populations and the ecosystems they inhabit. By embracing a holistic understanding of trees and their environments, professionals can contribute to shaping future landscapes that support both human well-being and biodiversity. [ABSTRACT FROM AUTHOR]

Copyright of Arboriculture & Urban Forestry is the property of International Society of Arboriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tiempos Modernos is the property of Tiempos Modernos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Observations of tree canopy structure are routinely used as an indicator of tree condition for the purposes of monitoring tree health, assessing habitat characteristics or evaluating the potential risk of tree failure. Trees are assigned to broad categories of structural condition using largely subjective methods based upon ground-based, visual observations by a surveyor. Such approaches can suffer from a lack of consistency between surveyors; are qualitative in nature and have low precision. In this study, a technique is developed for acquiring, processing and analysing hemispherical images of sessile oak (Quercus petraea (Matt.) Liebl.) tree crowns. We demonstrate that by calculating the fractal dimensions of tree crown images it is possible to define a continuous measurement scale of structural condition and to be able to quantify intra-category variance of tree crown structure. This approach corresponds with traditional categorical methods; however, we recognize that further work is required to precisely define interspecies thresholds. Our study demonstrates that this approach has the potential to form the basis of a new, transferable and objective methodology that can support a wide range of uses in arboriculture, ecology and forest science. [ABSTRACT FROM AUTHOR]

One aim of the MIPP Project (http://www.lifemipp.eu) was to develop non-invasive monitoring methods for selected saproxylic beetles. In this paper, a method is proposed for monitoring the larvae of Osmoderma eremita in their natural habitat (i.e. hollow trees), using a conservation detection dog (CDD). Wood mould sampling (WMS), the standard method to detect hermit beetles and other saproxylic insects inside tree hollows, is time-consuming and exposes the target species and the whole saproxylic communities to some risks. In contrast, CDDs pose no risk to the species living inside trees while, at the same time, offer a powerful tool for surveying the insects. In this paper, the methods applied to train the dog are presented, together with the results for accuracy (the overall proportion of correct indications), sensitivity (the proportion of correct positive indications) and specificity (the proportion of correct negative indications) obtained once the CDD had been fully trained. Results are presented for nitrocellulose filters with the odour of the target species, for larvae living inside hollow trees, for frass and for the remains of adults. A comparison of the efficiency between CDD and WMS showed that employing the dog was much less time-consuming than WMS. The literature on training CDDs for nature conservation tasks, with particular reference to cases involving Coleoptera, was also reviewed. [ABSTRACT FROM AUTHOR]

Leaf aging is a fundamental driver of changes in leaf traits, thereby regulating ecosystem processes and remotely sensed canopy dynamics., We explore leaf reflectance as a tool to monitor leaf age and develop a spectra-based partial least squares regression ( PLSR) model to predict age using data from a phenological study of 1099 leaves from 12 lowland Amazonian canopy trees in southern Peru., Results demonstrated monotonic decreases in leaf water (LWC) and phosphorus (Pmass) contents and an increase in leaf mass per unit area (LMA) with age across trees; leaf nitrogen (Nmass) and carbon (Cmass) contents showed monotonic but tree-specific age responses. We observed large age-related variation in leaf spectra across trees. A spectra-based model was more accurate in predicting leaf age ( R2 = 0.86; percent root mean square error (% RMSE) = 33) compared with trait-based models using single ( R2 = 0.07-0.73; % RMSE = 7-38) and multiple ( R2 = 0.76; % RMSE = 28) predictors. Spectra- and trait-based models established a physiochemical basis for the spectral age model. Vegetation indices ( VIs) including the normalized difference vegetation index (NDVI), enhanced vegetation index 2 (EVI2), normalized difference water index (NDWI) and photosynthetic reflectance index (PRI) were all age-dependent., This study highlights the importance of leaf age as a mediator of leaf traits, provides evidence of age-related leaf reflectance changes that have important impacts on VIs used to monitor canopy dynamics and productivity and proposes a new approach to predicting and monitoring leaf age with important implications for remote sensing. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Given a collection of phylogenetic trees on the same leaf label-set, the Maximum Agreement Forest problem ( Maf) asks for a largest common subforest of these trees. The Maf problem on two binary phylogenetic trees has been studied extensively. In this paper, we are focused on the Maf problem on multiple (i.e., two or more) binary phylogenetic trees and present two polynomial-time approximation algorithms, one for the Maf problem on multiple rooted trees, and the other for the Maf problem on multiple unrooted trees. The ratio of our algorithm for the Maf problem on multiple rooted trees is 3, which is an improvement over the previous best ratio 8 for the problem. Our approximation algorithm of ratio 4 for the Maf problem on multiple unrooted trees is the first constant ratio approximation algorithm for the problem. [ABSTRACT FROM AUTHOR]

This paper describes a research project exploring future urban forests. This study uses a Delphi approach to develop a set of key indicators for healthy, resilient urban forests. Two groups of experts participated in the Delphi survey: International academics and local practitioners. The results of the Delphi indicate that "urban tree diversity" and "physical access to nature" are indicators of high importance. "Tree risk" and "energy conservation" were rated as indicators of relatively low importance. Results revealed some differences between academics and practitioners in terms of their rating of the indicators. The research shows that some indicators rated as high importance are not necessarily the ones measured or promoted by many municipal urban forestry programs. In particular, social indicators of human health and well-being were rated highly by participants, but not routinely measured by urban forestry programs. [ABSTRACT FROM AUTHOR]

Society has placed greater focus on the ecological service of urban forests; however, more information is required on the variation of carbon (C) in trees and soils in different functional forest types, administrative districts, and urban-rural gradients. To address this issue, we measured various tree and soil parameters by sampling 219 plots in the urban forest of the Harbin city region. Averaged tree and soil C stock density (C stocks per unit tree cover) for Harbin city were 7.71 (±7.69) kg C⋅m-2 and 5.48 (±2.86) kg C⋅m-2, respectively. They were higher than those of other Chinese cities (Shenyang and Changchun), but were much lower than local natural forests. The tree C stock densities varied 2.3- to 3.2-fold among forest types, administrative districts, and ring road-based urban-rural gradients. In comparison, soil organic C (SOC) densities varied by much less (1.4-1.5-fold). We found these to be urbanization-dependent processes, which were closely related to the urban-rural gradient data based on ring-roads and settlement history patterns. We estimated that SOC accumulation during the 100-year urbanization of Harbin was very large (5 to 14 thousand tons), accounting for over one quarter of the stored C in trees. Our results provide new insights into the dynamics of above- and below-ground C (especially in soil) during the urbanization process, and that a city's ability to provide C-related ecosystem services increases as it ages. Our findings highlight that urbanization effects should be incorporated into calculations of soil C budgets in regions subject to rapid urban expansion, such as China. [ABSTRACT FROM AUTHOR]

The carbon stored in small diameter trees of temperate forests has been ignored in most studies and there is a lack of biomass equations for this component of forests. We harvested nine main tree species at sapling stage (dbh < 8 cm) across different site conditions (from 100 to 1700 m a.s.l). For each species, 10–12 individuals were selected randomly and harvested. Using nonlinear seemingly unrelated regression (NSUR), additive species-independent equations were developed for estimation of biomass of foliage, branch, bole, and total based on dbh, height, and wood density as predictors. Results showed that wood density and height had high effects on equations performance except for the foliage equations. Comparing actual and estimated biomass for each species revealed that these equations can be used for new species in similar forests. [ABSTRACT FROM AUTHOR]

Savanna ecosystems cover 20% of the global land surface and account for 25% of global terrestrial carbon uptake. They support one fifth of the world's human population and are one of the most important ecosystems on our planet. Savanna productivity is a product of the interplay between trees and grass that co-dominate savanna landscapes and are maintained through interactions with climate and disturbance (fire, land use change, herbivory). In this study, we evaluate the temporally dynamic partitioning of overstory and understory carbon dioxide fluxes in Australian tropical savanna using overstory and understory eddy covariance measurements. Over a 2-year period (September 2012 to October 2014) the overall net ecosystem productivity (NEP) of the savanna was 506.2 (±22 SE) g Cm-2 yr-1. The total gross primary productivity (GPP) was 2267.1 (±80 SE) g Cm-2 yr-1, of which the understory contributed 32 %. The understory contribution was strongly seasonal, with most GPP occurring in the wet season (40%of total ecosystem in the wet season and 18%in the dry). This study is the first to elucidate the temporal dynamics of savanna understory and overstory carbon flux components explicitly using observational information. Understanding grass productivity is crucial for evaluating fuel loads, as is tree productivity for quantifying the tree carbon sink. This information will contribute to a significant refinement of the representation of savannas in models, as well as improved understanding of relative tree-grass productivity and competition for resources. [ABSTRACT FROM AUTHOR]

Forest thinning, which removes some individual trees from a forest stand at intermediate stages of the rotation, is commonly used as a silvicultural technique and is a management practice that can substantially alter both forest canopy structure and carbon storage. Whilst a proportion of the standing biomass is removed through harvested timber, thinning also removes some of the photosynthetic leaf area and introduces a large pulse of woody residue (brash) to the soil surface, which potentially can alter the balance of autotrophic and heterotrophic respiration. Using a combination of eddy covariance (EC) and aerial light detection and ranging (lidar) data, this study investigated the effects of management thinning on the carbon balance and canopy structure in a commercially managed oak plantation in the south-east of England. Whilst thinning had a large effect on the canopy structure, increasing canopy complexity and gap fraction, the effects of thinning on the carbon balance were not as evident. In the first year post thinning, the peak summer photosynthetic rate was unaffected by the thinning, suggesting that the better illuminated ground vegetation and shrub layer compensated for the removed trees. Peak summer photosynthetic rate was reduced in the thinned area between 2009 and 2011, but there was no significant difference between sectors. Ecosystem respiration fluxes increased in the thinned relative to the unthinned area in the post-thinning phase. [ABSTRACT FROM AUTHOR]

Female choice based on multiple male traits, rather than on any single one, has been reported in many species and may well be a rule rather than an exception. However, the implications this has for selection acting on choosiness itself remain underappreciated. We argue that this constitutes one of the important impediments to our understanding of the evolution of mate choice. We discuss this issue primarily in the context of the Fisherian model of sexual selection. We review theory and empirical data, showing how the crucial parameter of the model-genetic variation in male attractiveness-can be estimated when attractiveness is a function of multiple traits. Based on the reviewed theory, we show how relying on individual male traits, instead of overall attractiveness, can produce biased estimates of Fisherian benefits of female choice. This bias can be substantial, especially when many traits contribute to male attractiveness. We discuss a number of methodological issues that, we hope, will stimulate future studies and help resolving the long-standing mystery of mate choice. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agricultural Science & Technology is the property of Hunan Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urban forest professionals struggle with public recognition and a clear identity in spite of growing demand for their expertise. No single credential or professional support system defines or unites urban forest professionals, who instead rely on several closely allied professions for professional support. This reliance is thought to contribute to this lack of recognition and indistinct professional identity. Thus we asked urban forest professionals if they believed the urban forestry profession needs its own credential and, if such a credential were available, would they obtain it. An international survey resulted in 749 respondents from 13 countries, with the vast majority from the United States and Canada. On average, respondents believed a credential was needed and would obtain it if offered. Late-career professionals were less likely to say they would obtain such a credential, while there was some evidence that women and early-career respondents are more likely. Some groups, most notably the self-employed, were much less likely to think a credential was needed and even less likely to obtain it were it to be offered. Respondents already hold 2.38 credentials on average, the most commonly held credentials being from the closely allied professions of arboriculture and forestry. Without specifying the format or scope, the survey asked respondents for opinions about a hypothetical urban forestry credential. Respondents raised concerns related to whether a credential could embrace the full scope of urban forestry, whether there was overlap or redundancy among existing credentials, and the cost of obtaining additional credentials. In addition, respondents noted credentials may need to align with diverse regulatory and employment environments. Nonetheless, open-ended responses overwhelmingly noted that urban forestry has emerged as a distinct profession that merits a credential to support a unifying identity and recognize the specialized training required. • We asked urban forest professionals if the profession needs its own credential. • Respondents consider urban forestry a distinct profession and support a credential. • A credential could foster professional identity, but concerns exist about format. • Early-career professionals are likely to obtain a credential if it is offered. • Respondents hold a wide variety of credentials with 45% holding 3 or more. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is an essential nutrient that is highly abundant as N2 in the atmosphere and also as various mineral and organic forms in soils. However, soil N bioavailability often limits the net primary productivity of unperturbed temperate forests with low atmospheric N input. This is because most soil N is part of polymeric organic matter, which requires microbial depolymerization and mineralization to render bioavailable N forms such as monomeric organic or mineral N. Despite this N limitation, many unfertilized forest ecosystems on marginal soil show relatively high productivity and N uptake comparable to agricultural systems. The present review article addresses the question of how this high N demand is met in temperate forest ecosystems. For this purpose, current knowledge on the distribution and fluxes of N in marginal forest soil and the regulation of N acquisition and distribution in trees are summarized. The related processes and fluxes under N limitation are compared with those of forests exposed to high N loads, where chronic atmospheric N deposition has relieved N limitation and caused N saturation. We conclude that soil microbial biomass is of decisive importance for nutrient retention and provision to trees both in high and low N ecosystems. [ABSTRACT FROM AUTHOR]

Bioactive gibberellins ( GAs) have been implicated in short day ( SD)-induced growth cessation in Populus, because exogenous applications of bioactive GAs to hybrid aspens ( Populus tremula × tremuloides) under SD conditions delay growth cessation. However, this effect diminishes with time, suggesting that plants may cease growth following exposure to SDs due to a reduction in sensitivity to GAs., In order to validate and further explore the role of GAs in growth cessation, we perturbed GA biosynthesis or signalling in hybrid aspen plants by overexpressing At GA20ox1, At GA2ox2 and Ptt GID1.3 (encoding GA biosynthesis enzymes and a GA receptor)., We found trees with elevated concentrations of bioactive GA, due to overexpression of At GA20ox1, continued to grow in SD conditions and were insensitive to the level of FLOWERING LOCUS T2 ( FT2) expression. As transgenic plants overexpressing the Ptt GID1.3 GA receptor responded in a wild-type ( WT) manner to SD conditions, this insensitivity did not result from limited receptor availability., As high concentrations of bioactive GA during SD conditions were sufficient to sustain shoot elongation growth in hybrid aspen trees, independent of FT2 expression levels, we conclude elongation growth in trees is regulated by both GA- and long day-responsive pathways, similar to the regulation of flowering in Arabidopsis thaliana. [ABSTRACT FROM AUTHOR]

Abstract: Information on changes in urban green spaces and the causes of these changes is important for urban planning. In this study the trends of urban green coverage (UGC) between 1990 and 2010 in 30 major Chinese cities were studied using classified Landsat satellite images. Associations between the trends and natural and socio-economic variables were analyzed using the maximum information-based nonparametric exploration method. The results showed that, overall, the studied cities have become greener over the past two decades. Greening in old city districts and expanded built-up areas (BUAs) led to the increase of urban green coverage at a mean annual rate of 1.51%. However rapid urbanization also caused a dramatic turn-over in vegetation covers. On a regional scale, around 46.89% of original vegetation cover was converted to other land cover types. The trends of UGC cannot be attributed to any one of natural or socio-economic variables alone. The combined influences of economic growth, climate change, and urban greening policies are the most likely causes behind the detected trend. One lesson from this study is that the preservation of existing vegetation cover must be a priority in urban greening programs. [Copyright &y& Elsevier]

Winter activity of earwigs has not been intensively studied until now. This study provides the first systematic data on winter activity of Chelidura guentheri (Dermaptera: Forficulidae) and its habitat preferences during this period. Most of the specimens were collected during two winter seasons; 2000/2001 and 2001/2002. To detect Dermaptera activity on the ground and under snow cover pitfall traps were used, and to collect earwigs active on the snow surface Moerick's traps were used. Three species of Dermaptera were collected during winter, also from under the snow: Chelidura guentheri, Forficula auricularia and Apterygida media. In the collected material, C. guentheri predominated, while the two other species were noted occasionally. The highest winter activity of earwigs was noted in beech forests, while the lowest was recorded in riparian forests. The results show that earwigs can be a significant element of subnivean invertebrate activity, but they appear on the snow surface only accidentally. The most abundant earwig was an omnivorous species, which may play a role in subnivean food chains [ABSTRACT FROM AUTHOR]

The article examines the methodological and theoretical issues provoked by local responses to landmark trees in Australia including Leichhardt tree in Borroloola. It is mentioned that an act of arson was used to destroy the Landsborough tree in 2002 to provoke heated passions among the nearby residents in Burketown.

Forests have economic, ecological, social and cultural functions. Forests Cultural ecology, the counterpart of forest ecology, is the integration of human spirit formed on the basis of natural forest and living systems. In recent years, China's urbanization rate has increased from 28% in 1993 to 45.68% in 2008, and ecological protection of urban forest has made great progress, but insufficient attention was paid to the forest cultural ecology protection and the relevant regulatory was not well performed. In order to strengthen the protection of forest cultural ecology and the management, the study showed that the social economic development of China has become mature and entered the consumption phase, besides, cultural ecology protection of forest will be the essence of urban forestry development in the future, so more and more attention will be paid to the protection of urban forest cultural ecology, especially with the enhancement of urbanization in China. The study suggests that protection of urban forest cultural ecology should be included into the forest legislation and management. The development planning of urban forest development should be strengthened to highlight the organic combination of material wealth production and spiritual wealth production, and finally promote protection of urban forest culture and the development of green culture. [ABSTRACT FROM AUTHOR]

The perception of linkages between ecosystem services (ES) and the urban green infrastructure (UGI) is evaluated, and their impact on human well-being (WB) is defined. Using a theoretical approach, the UGI's specific contribution to WB is calculated as the sum of the products of (a) the number of perceived ES per ES group and the WB weight factor divided by the product of (b) the number of respondents and (c) the sum of the products of ES and the WB weight factor. Stakeholders demand more ES than the perceived ES supply from all types of UGI, especially for the social relations component of WB. The highest number of perceived ES and greatest impact on all WB components is provided by urban forests. This method could be helpful in acknowledging ES and involving stakeholders not previously familiar with the ES concept with the aim of introducing ES into UGI governance. [ABSTRACT FROM AUTHOR]

The article presents a review of the Quantified Tree Risk Assessment (QTRA) system. For this review, QTRA was examined based on the principle of Qualified Risk Assessment (QRA) which has been widely used in risk management since the 1960s in several systems including aviation, nuclear power and medical treatment. The author stresses the need for risk management process that involves trees, not only to assess risk, but also to weigh the benefits provided by trees.

The article presents a study on the status, needs and knowledge levels of the community leaders of Mississippi. It notes that this study aims to build on past research and identify the trends for past and current involvement and future interests levels among the small and large communities in Mississippi for urban and community forestry programs and assistance. For this study, a mail survey was sent to 293 Mississippi communities. A total of 163 surveys returned.

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks. [ABSTRACT FROM AUTHOR]

Long-term changes for invasive trees and shrubs presence in 16 floras encompassing four remnant urban forests of the coastal northeastern United States were examined for relationships with arboricultural introductions' residence time and planting intensity, and state level recognition of regional invasive woody taxa. The number of invasive woody taxa significantly increased over the period 1818 to 2011 which encompasses the 16 floras. No significant Pearson product moment correlations were found for residence time as the year of introduction to arboriculture with presence in the 16 floras as well as with the 4 most recent floras. In contrast to residence time, planting intensity from the North American flora and two botanical gardens floras of the region from 1811 to 1818 and New York and Philadelphia parks floras from 1857 to 1903 did have significant correlations with the 16 floras and the 4 most recent floras. State level recognition of regional invasive woody taxa showed significant correlations with presence in all 16 floras as well as the 4 most recent floras. Monitoring for range expansion by the regional invasive woody taxa is essential because only 18% of the 98 taxa are present in all 4 of the most recent floras. [ABSTRACT FROM AUTHOR]

There is a growing body of evidence demonstrating that tree survival is influenced by negative density-dependence, but it is still controversial how the effect may vary with life-stage, and to what extent it plays a role in regulating tree survival in heterogeneous subtropical forests. In this study, we investigated density-dependent effects on tree survival of six tree species in a 5-ha subtropical forest in eastern China. The roughly 45 000 individuals in the forest were fully censused in 2003 and 2008. For each of these species, we used an inhomogeneous pair-correlation function to quantify the change in spatial distribution for different size classes, and a case-control design to study seedling-adult associations in 2003. Autologistic regression was used to determine the influence of neighborhood factors on individual survival from 2003 to 2008. We found that seedlings of five species were repulsed by distance to nearest conspecific adults in terms of their survival, consistent with predictions of the Janzen-Connell mechanism. By contrast, only the least shade-tolerant Schima superba had a negative relationship with individual survival and conspecific distance-weighted basal area. This suggests that the Janzen-Connell effect is only prevalent at the early seedling stage or seed-to-seedling phase. The strength of clustering significantly declined at sapling-pole and pole-adult transitions for Sycopsis sinensis and at seedling-sapling transition for Cleyera pachyphylla. Correlations between individual survival and conspecific abundance for these species were consistent with trends in the strength of clustering. These results suggest that density dependence plays a limited role in individual survival and species spatial structure beyond the early seedling stage (i.e. after true leaves growing) in this forest. In addition, this study indicates that including individuals from early life-stages and factoring out potential confounding factors such as habitat preference are important in studies that seek evidence for density dependence in forest trees. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the author's insights regarding trees and what he terms "ecophilia" and "ecophobia" in the Front Range area of Colorado. The author, an arborist, relates why he loves trees and presents anecdotes related to the removal of trees and the line between urban environments and nature. He also reflects on ecophobia, or people's opposition to nature and trees.

The article discusses the findings of a study to determine the effectiveness of using toothed rope-ascenders for standard climbing ropes of arborists. Experts have questioned the use of ascenders in arboriculture due to its limitations in relation to rope construction and diameter, and the need for climbers to incorporate safety lines. It describes the testing of Petzl Ascension ascenders on arborist climbing ropes and a static rescue rope using the EN 12841-2006 Standard for Type B rope grabs.

Trees are a major threat to power line security across forested regions of the world. We developed a decision support system for identifying locations in Connecticut, USA where trees have grown tall enough to make contact with transmission lines during storms. We used the Random Forest algorithm, danger tree presence/absence data, and 25 raster environmental datasets to develop (1) an understanding of the abiotic environmental settings that host danger trees and (2) a spatially explicit map of danger tree distributions across Connecticut power line corridors. Danger trees were prevalent in locations (1) with an infrequent history of storms; (2) forested and residential land uses; and (3) low to middle elevations. Products from this research can be transferred to adaptive right-of-way management because they present managers with key information on where danger trees are likely to occur, and the methods presented herein have great potential for future application to other regions managers seek to identify high priority areas for danger tree removal. [ABSTRACT FROM AUTHOR]

In the last decades, production forestry plantations has been developed using typical forest tree species, or species of agricultural interest, such as walnut and cherry. The use of these species in a context different than the traditional one put a number of problems not easy to solve. The present study has considered some timber-quality plantations of hardwoods species (Acer pseudoplatanus L., Prunus avium L., Fraxinus excelsior L., Juglans regia L.) established on the Serre Catanzaresi (VV), with the aim of assessing the achievements obtained both in quantitative (growth) and qualitative (shape of the stems, degree of branching) terms. The results of the analyses carried out revealed that the studied plantations are an interesting example of possibilities and limits of cultivation of commonly used hardwoods in relation to the practices adopted. The observed differences are mainly related to the different species used. Some of them (sycamore and wild cherry) guaranteed satisfactory results, others (ash and walnut) showed severe limitations, due to the poor quality of planting material, the incompatibility between the species needs and site characteristics, or because these species usually constitute mixed populations. [ABSTRACT FROM AUTHOR]