European Journal of Forest Research最新文献

The forests along the southern Baltic Sea coast harbour some stands of the rare and endangered European yew (Taxus baccata L.), which are hypothesised to be autochthonous. Using the example of an occurrence on the Darss-Zingst peninsula, the population dynamics of the yew since the late Holocene are interdisciplinarily investigated and linked to the forest history of this area. Pollen analysis shows that yew has been present in the study area for at least 2600 years and thus indeed represents an autochthonous tree species in the area. The yew was probably originally part of a second tree storey and of forest margins within a mixed forest mainly consisting of several deciduous tree species and Scots pine. Historical evidence reveals that yew was still occurring in the forest in the middle of the eighteenth century, but then had nearly disappeared by the end of the nineteenth century. This was caused by several factors including forest grazing by livestock, high game populations and clear-cutting. First replanting of yew took place in the 1930s/1940s and 1950s/1960s, followed by planting campaigns in the 1990s and 2000s. Planting material from local and regional autochthonous relict populations was used, at least in part. The current yew population mainly comprises young individuals with a total number of ca. 1300 trees. It has thus been possible here to re-establish an autochthonous yew occurrence that was nearly extinct in historical times. This local example of targeted re-enrichment of native tree diversity may also encourage further measures to give this species a new chance again elsewhere in the wider region.

Industrial economic activities produce pollutants and environmentally sustainable production systems in forestry aim to minimize these undesirable outputs while maintaining high production and economic growth. In this contribution, we assume that in addition to plot-specific inputs and outputs, there are some contextual variables that may be exogenously fixed or may be under the control of the decision-makers. In this sense, we first propose a novel and practical approach to calculate environmental efficiency by reducing undesirable products. Then, we utilize an inverse data envelopment analysis (IDEA) model to effectively manage and reduce CO₂ emissions. In doing so, the applied models have been utilized to evaluate the efficiencies of 89 forest plots in the USA. Given our estimations in a real application to the forest plots, the study revealed that the average environmental efficiency score is nearly 0.75 (out of 1). However, there is potential for improvement by adjusting the impacts of contextual factors, which could raise the score to approximately 0.8. Furthermore, the analysis indicates a positive correlation between ownership and environmental efficiency, suggesting that increased ownership leads to higher environmental efficiency. Conversely, temperature exhibits a negative correlation with environmental efficiency. Finally, the results obtained from the IDEA indicate that in order to reduce undesirable outputs by a specific level of 5–10%, it is necessary to decrease other inputs and outputs. This is because, under the assumption of weak disposability, reducing the level of undesirable outputs requires a reduction in certain factors that influence production capacity. In other words, achieving the desired reduction in undesirable outputs inevitably involves diminishing certain aspects of the production process. As the major conclusion, the emergence of IDEA as a powerful tool for sensitivity analysis, along with its flexible nature, offers exciting opportunities for research and practical applications in various fields, including forestry activities. It has the potential to enhance overall environmental efficiency and enable better control over GHG emissions levels.

Abstract

Understanding the variation in fecundity, the reproductive capacity of individual trees, is crucial for predicting population dynamics and ecosystem functioning. However, estimating tree fecundity is challenging due to the large variation in seed production observed between trees and across years that necessitates logistically challenging long-term monitoring. This study aimed to investigate the factors influencing fecundity in rowan trees (Sorbus aucuparia) using a 22-year fruit-count dataset in 167 individual trees. We examined the relationship between fecundity and intrinsic (DBH, height, and leaf nutrient concentration) and extrinsic factors (soil nutrients, light availability, and neighborhood crowding). Our findings revealed that diameter at breast height (DBH) better explained variation in fecundity than height. After accounting for tree size using DBH, light availability had the strongest, positive effect on fecundity and was the major limiting factor for rowan’s fecundity. At the same time, neighborhood crowding index with conspecifics also showed significant, but negative correlation with fecundity, suggesting competition for pollinators among rowan trees. Our findings contribute to a better understanding of seed production ecology and can inform management and conservation efforts that aim for increased fruit supply, either for plant populations or fruit consumers.

Forests provide irreplaceable ecosystem services for human society and prevent environmental degradation but climate change has substantially undermined these fundamental functions. It is therefore important to examine the responses and adaptation of different tree species to climate warming. Here, we investigated how climate warming has affected tree growth patterns and growth-climate responses of a conifer (Pinus tabuliformis) and two broad-leaved species (Populus davidiana and Betula platyphylla) in a temperate semi-arid region in the northern China. Our results showed that P. tabuliformis had a similar regional growth pattern and two broad-leaved species shared an interspecific growth similarity at the same site. Broad-leaved trees had a higher recovery and resilience to drought than the conifer while conifers were more resistant to drought compared to broad-leaved trees, indicating a faster drought-response of broad-leaved species than that of conifers. The warming climate has hindered the tree growth by exacerbating water-deficit, and in particular, water availability has become the limiting factor for the growth of pines in the area. Trees coped with the water-deficit by taking advantage of non-growing season water to compensate the water source for tree growth. The study not only revealed the differences of growth-climate responses between species but also highlighted the necessity to consider species-specific adaptation to climate warming and diversify forest management strategies.

Canopy gaps are a prevalent disturbance form in forest ecosystems that promote forest regeneration and succession by modifying the heterogeneity of the microenvironment. However, a significant knowledge gap exists in comprehending the global-scale impact of canopy gaps on soil nutrient properties, which is related to forest management and conservation tactics. In this study, 518 paired observations derived from 31 peer-reviewed articles were meta-analyzed to evaluate the overall response of soil nutrient properties to canopy gaps. The results showed that canopy gaps increased NO₃⁻–N (+ 22.20%) and MBP (+ 194.17%). The canopy gap decreased the content of TN, MBC, and C:P ratio by 9.27%, 19.58%, and 19.25%, respectively. The size of canopy gaps significantly reduced SOC (−14.37%), MBC (−27.45%), TN (−11.98%), NH₄⁺–N (−65.26%), C:N (−15.77%, −16.02%) and C:P ratio (−28.92%), but significantly increases NO₃⁻–N (+ 37.25%). Hence, it is advisable to establish a critical gap size that caters to the specific soil fertility requirements of various regions for the optimal release of soil nutrients. These findings hold substantial significance for optimizing canopy gap management, comprehensively understanding the impact of canopy gaps on soil nutrient properties, and facilitating decision-making to assess soil fertility following canopy gap disturbances.

The distance between forest and forest villages as a factor has specific importance in designing the interface of forest dependency. Scholars have widely adopted the forest dependency model, which, by indirectly utilising the distance decay principle, can interpret the distance impact on forest dependency. The present empirical study thus attempted to understand how, in the case of Indian forestry, community dependency altered in relation to its distance from the forest. What are the associated elements that shaped such differences, and finally, is it possible for the existing forest dependency model to explain this distance interference using the distance decay principle? In achieving these goals using multiple linear regression, the study tried to understand the impact of distance along with other factors of forest dependency in an Indian protected forest region. Further, using bivariate logistic regression, it identified the differential pattern of dependency in the forest core and fringe villages in association with their purposes and the nature of the collection. Finally, the overall findings revealed a different kind of distance and forest dependency interrelation based on the differential purposes and nature of collections that denied the acceptance of the above-mentioned model and principle in the setting of forest dependency in rural India.

Induced by climate change associated disturbances and further promoted by changes in forest management, the proportion of European beech, a highly competitive climax species, is increasing in Central Europe. However, its climatic stability is questioned by the recent loss of vitality. In this regard, the evaluation of seed sources used for reforestation receives great attention. Here, we present a multi-trait evaluation of height, basal area and stem quality assessed over 25 years for 85 provenances grown at three sites in northern, western and eastern Germany. Considerable provenance differentiation exists, explaining 21% (proportion of trees with acceptable stem form) to 45% (basal area) of the variance on single sites and 20 to 39% across sites, while provenance by environment interactions are absent. On the landscape level, this results in distinct patterns with spatially adjacent provenances showing a similar trait expression. These patterns are highly similar for height and basal area but divergent for stem form. They could be directly linked to geographic variables with multivariate regression tree analysis that captured 58% of the phenotypic variation, delineating eleven ‘ecotypes’ shaped by local adaptation. A selection based on two multi-trait indices gives highly concordant results. Particularly, the intermediate elevations of the central highlands in Western Germany host highly suitable provenances. Lower elevation provenances from continental climates in the south-east profit from the transfer to favorable growing conditions. Since the majority of provenances was already exposed to elevated temperatures compared to their origin during the observation period, this study gives a first indication for the potential benefits of assisted migration facing climate change.

Improving water-holding functions is an important purpose of sustainable forest management. However, few studies have examined whether there are differences in water-holding capacities between the forests dominated by trees associated with different mycorrhizal types and what are the main factors leading to the differences. Here, we investigated seven parameters of water-holding capacities of soils, litter, and canopy interception in 210 forest plots (10 m × 10 m). The plots were equally divided into three forest types associated with mycorrhizal types, including AM plots (arbuscular mycorrhizal trees > 75% in dominance), ECM plots (ectomycorrhizal trees > 75%), and AM + ECM plots (between 25 and 75%). We calculated tree diversity (richness, Shannon–wiener index, Simpson index, evenness), community structure (diameter at breast height, height, under branch height, density, neighborhood comparison-U, uniform angle index-W, and mingling index-M), and soil physics (soil bulk density and field water content). The results showed that: (1) ECM-dominated communities increased 1.6–2.0-fold in the litter water-holding capacities than those of AM and AM + ECM. The canopy interception of the ECM community was the highest (0.97 mm), significantly higher than that of the AM + ECM community (0.58 mm). (2) The ECM community had lower field soil water-holding capacity (p < 0.05) but 42–78% higher soil non-capillary water capacity than that of AM and AM + ECM (p < 0.05). (3) ECM forests were characterized by low tree species evenness, big-sized trees, and low bulk density, favoring increasing ecosystem water-holding capacities. Moreover, increasing ECM tree dominance enhanced the contribution of community structure to water-holding variations. (4) ECM trees increased ecosystem water-holding functions by direct effects (mainly on the litter) and indirect effects from soil physics (mainly on the soils) or tree size (mainly on the canopy) regulations. This study highlighted that ECM trees enhanced water-holding capacity, providing important information for planting and managing temperate water conservation forests.

Tree decline is described as the loss in tree vigor and increased mortality initiated by climate change events, and also involves pathogens and pests. Stem bleeding and bark canker of oak (Quercus castaneifolia) were observed in Mazandaran and Golestan forests during summer 2020–2021. Symptoms included cracks in the outer bark, stem tissue necrosis, bleeding, dark exudate and dark brown lesions in the inner bark. Eighty-nine strains with a metallic green sheen pigment were isolated on eosin methylene blue agar. The pathogenicity of all strains recovered in this study was assessed on oak seedlings and acorns. Forty-four strains produced rotting on oak acorns 2 weeks after inoculation. Inoculation of six representative strains on oak seedlings resulted in twig dieback of the plants after 4 weeks. Strains were negative for Gram reaction, oxidase and levan formation from sucrose. The gyrB and infB gene sequence similarity values of strains were 98.87–99.57% with the type strain of Gibbsiella quercinecans, 98.66–98.86% with the type strain of Gibbsiella greigii and 99.46–99.64% with the type strain of Dryocola boscaweniae. In the phylogenetic tree based on concatenated sequences of gyrB and infB genes or each gene individually, the strains were divided into three clusters containing the type strains of G. quercinecans, G. greigii and D. boscaweniae, each with high bootstrap support and confirming their identity as belonging to these three species. To the best of our knowledge, this is the first report of oak bacterial canker caused by D. boscaweniae, G. greigii and G. quercinecans in Iran and the first report of D. boscaweniae associated with oak decline symptoms.

Climate changes have dramatically affected forest succession. However, how trees at different successional stages respond to climate warming is unclear in the subtropics. Here, we compared the radial growth (RW) and xylem features of the early-successional stage Castanea mollissima and late-successional stage Quercus fabri in subtropical forests and assessed their response to climate changes. All parameters, including RW, number of vessels (VN), vessel density (VD), mean (MVA) and total (TVA) vessel area, percentage of conductive area within xylem (RCTA), theoretical (Kh) and xylem-specific (Ks) hydraulic conductivity, except for MVA of C. mollissima were significantly higher than those of Q. fabri. During the drought period, a notable adverse correlation between two cluster parameters of Q. fabri, associated with hydraulic safety and efficiency, suggested a pronounced hydraulic trade-off in Q. fabri under drought conditions. Castanea mollissima was more sensitive to climate and more prone to hydraulic failure than Q. fabri. Temperatures and moisture conditions positively and negatively affected the hydraulic efficiency-related parameters of C. mollissima. Moisture conditions in the previous summer and winter were significantly negatively and positively related to the radial growth of both species. The impact of generalized warming was not evident due to variations in hydraulic strategies and species characteristics, trade-offs between non-growing and growing season climates, and specific competition. If climate warming continues, C. mollissima growth will probably significantly decline due to the increasing risk of hydraulic failure. Warming may accelerate species replacement and forest succession in the study area by changing their lifespans and competitive relationships.