Structure and diversity of small mammal communities of mountain forests in Western Carpathians

We sampled the small mammal (SM) community in mountain forest ecosystems of the Beskydy Mountains over 5 years in order to study associations with different types of forest habitat. Fourteen species were determined, three being eudominant (yellow-necked mouse—Apodemus flavicollis (45 %), bank vole—Clethrionomys glareolus (23.3 %) and field vole—Microtus agrestis (15.7 %) and one dominant common shrew—Sorex araneus (9.3 %)). Highest abundance was observed in young succession sites (plantations) with dicotyledonous plants dominant (>50 %) in the undergrowth. Highest diversity was observed in plantations and primeval forests. Lowest total abundance and diversity were observed in mature monocultures. Significant differences in diversity were only found between old monocultures and other sites. Using a faunistic similarity index, two basic SM community groups were determined: those inhabiting (1) early (plantation) and late (reserve) successional forest ecosystems with a dense dicotyledonous plant herb layer, and (2) plantations with a dense grass herb layer and forests with a dense canopy closure (fruiting monoculture). Redundancy analysis confirmed separate habitat preferences of the three eudominant species. Generalised linear model indicated increasing preference of field vole for plantations with dominance of grass and <10–15 % admixed dicotyledonous plants while decreasing preference at ratios >10–15 %, and increasing preference of bank vole for plantations with a dicotyledonous plant ratio of >10–15 %. The biotopes monitored proved suitable for long-term survival of the dominant SM species. Early successional plantations and forest reserves also represent important refuges for a number of rarer SM species presently under threat.     

Response of seasonal pond plant communities to upland forest harvest in northern Minnesota forests,USA

Small seasonally flooded forest ponds have received increased attention due to a growing recognition of their abundance in many landscapes, their importance as habitat for a variety of organisms, and the contributions they make to species and ecosystem diversity. There also is concern over potential negative effects of forest management in adjacent uplands on seasonal pond ecology. Several studies have examined invertebrate and songbird responses to upland harvest around seasonal ponds. Less attention has been given to examining how seasonal pond plant communities respond to adjacent forest harvesting. We studied the response of seasonal pond plant communities to adjacent upland timber harvests, assessing whether buffers around ponds (15.25 m uncut and partially cut) mitigated changes in species abundance and community composition, relative to changes in ponds that were clearcut to the pond margin. We addressed our objective using an operational-scale experiment in northern Minnesota, which included pre-harvest sampling, replicated treatments, and uncut controls. After treatment, changes in tree basal area and canopy openness in the pond basins reflected reductions in upland basal areas. Specifically, control ponds had significantly higher basal area and lower openness than ponds cut to their margins, while ponds with uncut buffers and partially cut buffers were intermediate. Changes in plant communities were evident in the ground layer and shrub/large regeneration layer. After treatment and over time, the control stands did not change significantly in ground layer structure or shrub/large regeneration layer composition. The three upland harvest treatments displayed increasingly greater deviation from their starting conditions and from the control along a gradient of increasing treatment intensity, from the buffer treatment to the partially cut buffer to the clearcut. The response in the ground layer was largely associated with increased sedge and grass cover, while the response in the shrub/large regeneration layer was associated with increases of Salix sp., Alnus incana, and Populus tremuloides. Our results indicate that adjacent upland timber harvest can lead to altered plant communities within seasonal ponds, at least temporarily. Moreover, uncut forest buffers (∼15.25 m) surrounding seasonal ponds can mitigate plant community changes to some degree. If seasonal ponds are an important resource on the management landscape and a high percentage of upland forest is in a recently cut condition at any given time, than use of harvest buffers around seasonal ponds may be an appropriate approach for mitigating short term alteration of pond plant communities.     

Acidification of primeval forests in the Ukraine Carpathians: Vegetation and soil changes over six decades

Changes to vegetation and soil were assessed in primeval forests of the Eastern Carpathians after a period of 59-68 years. We hypothesized that forest ecosystems were acidified through the long-distance transport of air pollutants. A total of 141 relevés and 20 soil profiles that had been studied in 1938 in spruce- and beech-dominated forests along an altitudinal gradient ranging from 1085-1575 m a.s.l. were re-surveyed from 1997 to 2006. Relevés were analyzed using multidimensional statistics and plant community characteristics (Shannon-Wiener’s index, equitability, fidelity, Ellenberg indication values - EIV); soil reaction and sorption complex properties were analyzed in soils.A total of 159 vascular plant taxa were recorded in 1938, of which 35 were not found during the repeat survey. During the later survey, 137 taxa were found, of which 13 were new findings. The upper mineral (A) as well as cambic or spodic (B) horizons were considerably acidified in both forest types. Both active and exchange soil reaction decreased by 0.1-0.3 units on average, exchangeable acidity significantly increased and the sum of base cations decreased in both soil horizons and forest types. Base saturation decreased by more than half of original values, with a maximum decrease of 68% found in the B-horizon of spruce forests. Whereas the herb layer developed along with soils in beech-dominated forests, EIV values for soil reaction increased in spruce-dominated forests, probably due to the movement of broadleaf woody species to higher elevations or due to the higher resistance of herb species to soil acidification. Significant changes to EIVs also occurred in the beech- and/or spruce-dominated forests for the factors of nitrogen, light moisture and temperature.There was an expansion of the lower tree and shrub layers, primarily Fagus sylvatica, Picea abies and Sorbus aucuparia in intermediate and higher elevations, which can be explained by reduced cattle grazing. Also, the dissipation of Juniperus communis and marked decline of Abiesalba are interpreted as being related to gradual changes in landscape management along with the effect of acid deposition. Since 1938, all stands have shown a significant increase in nitrophilous taxa such as Rubusidaeus, Athyrium distentifolium, Urtica dioica, Calamagrostis arundinacea, Stellaria nemorum. Significant decreases in the number of species, Shannon-Wiener’s index and equitability were only observed in spruce-dominated forests. Neophyte taxa were not detected in either the 1930s or the 1997-2006 period.     

Short-term responses of soil decomposer and plant communities to stump harvesting in boreal forests

Recently, in addition to logging residues, stumps have become an important component in energy production since there is growing global interest in the use of renewable energy sources in order to decrease anthropogenic carbon emissions. Harvesting of stumps influences the forest floor by changing vegetation and soil organic layers and exposing mineral soil across large areas. We studied whether stump harvesting after clear felling poses further short-term changes in boreal forest soil decomposer community (microbes and mesofauna) and vegetation when compared to the traditional site preparation practice (mounding). In general, stump harvesting caused decline in enchytraeid abundance but did not induce further major changes in decomposer community otherwise nor in vegetation of each soil micro-habitat (intact soil and exposed mineral soil). However, the abundances of almost all decomposer animals were lower in the exposed mineral soil than in the intact soil. Stump removal increased the area of exposed mineral soil in the clear felled areas, leading to lower amount of high quality habitat for most decomposer organisms. Hence, it is obvious that there are (or will be) differences in the decomposer community dynamics between the treatments at the forest stand level. Both species richness and coverage of plants benefitted from large-scale exposure of mineral soil. Because the stump removal procedure disturbs soil organic layers and negatively affects the decomposer community, it has the potential to alter nutrient dynamics in forests.     

Plant diversity and phenological pattern in the montane wet temperate forests of the southern Western Ghats, India

Plants diversity and phenological pattern of the trees were monitored in a montane wet temperate forest (shola) in the     

Evidence of Pseudotsuga menziesii naturalization in montane Mediterranean forests

Invasion of natural habitats by conifer species is a well-known phenomenon worldwide. Here, we describe naturalization by the American Pseudotsuga menziesii (Douglas fir) in Montseny Natural Park (Catalonia, NE Spain). Establishment of seedlings started 15 years after plantation. Seedling density was positively associated to low tree density, small plantation area, grazing and the presence of a shrubland understorey of intermediate cover. Seedling recruitment outside the plantations occurred at high altitudes (>1000 m). In less than 30 years after plantation, P. menziesii invaded adjacent areas 100 m far from the plantation. We conclude that at high altitudes, under disturbance, seedling establishment can take place as soon as planted trees produce cones. Therefore, the time-lag appears to be primarily related to propagule availability.     

Understory plant communities of boreal mixedwood forests in western Canada: Natural patterns and response to variable-retention harvesting

We examined patterns of variation in richness, diversity, and composition of understory vascular plant communities in mixedwood boreal forests of varying composition (broadleaf, mixedwood, conifer) in Alberta, Canada, before and for 2 years following variable-retention harvesting (clearcut, 20 and 75% dispersed green tree retention, control). Broadleaf-dominated forests differed from mixedwood or conifer-dominated forests in that they had greater canopy cover, litter depth, soil nitrogen, warmer soils, as well as greater shrub cover, herb and shrub richness and diversity (plot scale). In contrast, conifer, and to a lesser extent mixedwood, forest had greater β diversity than broadleaf forest. Overall, mixedwood and conifer forests were similar to one another, both differed from broadleaf forest. Several species were found to be significant indicators of broadleaf forest but most of these also occurred in the other forest types. Understory composition was related to canopy composition and edaphic conditions. Variable-retention harvesting had little effect on understory cover, richness, or diversity but resulted in reduced richness and β diversity at a larger scale. The clearcut and 20% treatments affected composition in all forest types. Early successional species and those common in disturbed sites were indicators of harvesting while evergreen, shade-tolerant understory herbs were indicators of the control forest and 75% retention harvest. We conclude that it is important to maintain a range of variation in canopy composition of mixedwood forests in order to conserve the associated understory communities. The presence of conifers in these forests has a particularly important influence on understory communities. The threshold for a lifeboat effect of variable-retention harvesting is between 20 and 75% retention. Examination of richness and β diversity at a variety of scales can provide interesting information on effects of harvesting on spatial reorganization and homogenization of understory plant communities.     

Variation of endophytic cork oak‐associated fungal communities in relation to plant health and water stress

The main objective of this study was to obtain more comprehensive knowledge about the effect of water stress on endophytic fungal communities in asymptomatic and declining cork oak trees. Six asymptomatic and six declining cork oak trees were randomly selected in a natural cork oak forest located in Sardinia, Italy. In February 2003, the soil around three asymptomatic and three declining trees was covered with a circular plastic film to reduce rain water supply with the intention to induce water stress. The remaining six trees served as controls. Predawn xylematic water potential (PWP) was used as water status indicator and measured seasonally. Between July 2003 and June 2004, fungal endophytes were isolated every 2–4 months from twigs, branches and woody tissues. Significant differences in PWP between covered and control trees were detected mainly in autumn. Gas exchange was greatest in asymptomatic control plants. All tissues were colonized by endophytic fungi. Nineteen fungal species were isolated from 1620 plant fragments. Biscogniauxia mediterranea was the most frequently isolated fungus. Its isolation frequency was significantly higher in declining covered trees than in control trees (p < 0.05). Presence of this fungus in asymptomatic control trees was significantly higher in winter than in summer. Water stress seems to reduce species diversity of the endophytic mycobiota in cork oak and to promote proliferation of some potentially pathogenic endophytes.     

Disturbance changes arbuscular mycorrhizal fungal phenology and soil glomalin concentrations but not fungal spore composition in montane rainforests in Veracruz and Chiapas,Mexico

Mexican montane rainforests and adjacent disturbed areas were studied for disturbance-related spatio-temporal changes to the arbuscular mycorrhizal fungal (AMF) community and soil glomalin concentration. The AMF community functions to both improve plant growth and soil conditions and is thus an important component to the restoration of this forest type to disturbed areas. The study areas included mature rainforests that were converted to pine forests, milpas, pastures and shrub/herbaceous plant communities via burning and logging. Seasonal patterns in AMF spore species richness and sporulation significantly differed across disturbance types at two of the three sites surveyed. Contrasting patterns of sporulation among AMF families across different disturbance types helped to explain how species richness and composition were maintained despite dramatic changes to the host plant community. Meaning, in most cases, disturbance induced changes in when different AMF taxa sporulated but not what taxa sporulated. Only conversion from mature pine–oak–Liquidambar–Persea forests to pine-dominated stands severely reduced AMF spore richness and total sporulation. Surprisingly, in pine-dominant stands no concomitant negative impacts on soil glomalin (MAb32B11 immunoreactive soil protein) concentrations were detected. However, soils of mature forests containing no pines had the highest concentration of glomalin. Conversion to pasture and milpa (diverse cornfield) had a strong negative impact on the concentration of soil glomalin concentrations. In sharp contrast, the same disturbance types improved AMF sporulation and AMF spore richness. It appears that disturbance type, and not AMF community measures used herein, best predicts changes in soil glomalin concentration.     

蒙古栎林在温带落叶阔叶林群落分级中的地位

为清楚阐明蒙古栎林的群落分级及其在温带落叶阔叶林群落分级中的地位，我们收集了东北亚201个蒙古栎林和日本的153个栎林的资料．将其综合于一个简表中．并应用Braun—Blanquet方法对这些森林植被进行了比较。结果表明：在温带落叶阔叶林的群落分级系统中。蒙古栎林与水青冈纲占据着同等重要的地位，它们共同构成温带落叶阔叶林纲群(Class-group)。不同生境下的蒙古栎的20个群集或群落被归纳成为2个目、3个群团和3个亚群团。     

Influence of plant communities and soil properties on trace gas fluxes in riparian northern hardwood forests

Wetlands contribute significant amounts of greenhouse gases to the atmosphere, yet little is known about what variables control gas emissions from these ecosystems. There is particular uncertainty about forested riparian wetlands, which have high variation in plant and soil properties due to their location at the interface between land and water. We investigated the fluxes of carbon dioxide (CO₂), nitrous oxide (N₂O), and methane (CH₄) and associated understory vegetation and soil parameters at five northern hardwood riparian sites in the Adirondack Park, NY, USA. Gas fluxes were measured in field chambers 4 times throughout the summer of 2008. CO₂ flux rates ranged from 0.01 to 0.10 g C m⁻² h⁻¹, N₂O fluxes ranged from −0.27 to 0.65 ng N cm⁻² h⁻¹ and CH₄ flux rates ranged from −1.44 to 3.64 mg CH₄ m⁻² d⁻¹. Because we observed both production and consumption of N₂O and CH₄, it was difficult to discern relationships between flux and environmental parameters such as soil moisture and pH. However, there were strong relationships between ecosystem-scale variables and flux. For example, CO₂ and N₂O flux rates were most strongly related to percent plant cover, i.e., the site with the lowest vegetation cover had the lowest CO₂ and highest N₂O emissions. These ecosystem-scale predictive relationships suggest that there may be prospects for scaling information on trace gas fluxes up to landscape and regional scales using information on the distribution of ecosystem or soil types from remote sensing or geographic information system data.     

Ectomycorrhizal fungal communities of rehabilitated bauxite mines and adjacent,natural jarrah forest in Western Australia

Species richness and species composition of ectomycorrhizal (EM) fungi were compared among rehabilitated mine sites and unmined jarrah forest in southwest Western Australia. Species richness, measured in 50 m × 50 m plots, was high. In the wetter, western region, mean species richness per plot in 16-year-old rehabilitated mine sites (63.7 ± 2.5, n = 3) was similar to that of unmined jarrah forest (63.6 ± 9.6, n = 9). In the drier, eastern region, species richness in 12-year-old rehabilitated mine sites (40.3 ± 2.1, n = 3) approached that of nearby forest (52.4 ± 9.3, n = 9). Species composition was analysed by detrended correspondence analysis. Rehabilitated sites of similar age clustered together in the analysis and species composition was closer to the native jarrah forest in the older rehabilitated plots. In unmined forest, species composition of fungal communities in the wetter, western region was different from communities in the drier, eastern region.     

Environmental key factors and their thresholds for the avifauna of temperate montane forests

Mixed montane forests cover large tracts of the low mountain ranges that dominate Central Europe and also contain much of the area that is important to forest related nature conservation. However, beyond general patterns little is known about ecologically effective driving factors in this habitat. This results in a lack of precise values that can be used to formulate guidelines for nature conservation oriented management strategies. To improve this situation, we used birds as indicators for forest habitat qualities.     

Forest cover and pattern changes in the Carpathians over the last decades

This study aims at developing a satellite-based methodology for the implementation of two Ministerial Conference on the Protection of Forests in Europe indicators for the European Alpine Bio-geographic region, and their changes over time: (1) area of forest cover and (2) forest spatial pattern. The northern Carpathians were selected as a study area due to the documented recent increase of forest cover. Changes of forest cover were quantified using Landsat images for the years 1987 and 2000. Single-date forest–non-forest maps were derived by image segmentation and supervised classification, including the use of ancillary data (CORINE Land Cover and a digital elevation model). These maps were an input for the post-classification change detection. The forest spatial pattern maps with four classes (core, patch, edge and perforated forest) were derived with morphological image processing. A simple method to mask uncertainty areas on forest maps and related products was also developed. The accuracy of the resulting forest–non-forest map was assessed with orthophotos and amounts to 93.9%. Uncertainty areas, for which change assessment was judged more difficult and less reliable, were not considered for assessing forest cover change. The annual forest cover change rate of 0.38% was found over the 1987–2000 period. For the 13-year time period, we found a decrease of core forest and an increase of patch and perforated forest. We conclude that the proposed methodology allows to quantify changes of forest cover and forest spatial pattern at ∼1 ha minimum mapping unit.

Diversity of Ophiostomatales species associated with conifer-infesting beetles in the Western Carpathians

Bark beetles (Coleoptera: Curculionidae, Scolytinae) are commonly recognised as important agents of tree mortality in coniferous forests of the Western Carpathians. They, together with weevils, are consistently associated with ophiostomatoid fungi. Information regarding conifer beetle-associated fungi in the Western Carpathians remains incomplete and unreliable, particularly with respect to fir-infesting bark beetles. This study aims to clarify associations between fungi in the genera Graphilbum, Leptographium, Ophiostoma and Sporothrix (Ophiostomatales) and their beetle vectors in Norway spruce (Picea abies), European larch (Larix decidua) and silver fir (Abies alba). Samples associated with 20 bark beetle species and weevils were collected from nine stands in Poland and the Czech Republic. Fungi were isolated from adult beetles and galleries. Isolates were identified based on morphology, DNA sequence comparisons for four gene regions (ITS, LSU, ß-tubulin, TEF 1-α) and phylogenetic analyses. In total, 46 distinct taxa were identified, including 25 known and 21 currently unknown species. Several associations between fungi and subcortical insects were recorded for the first time. In addition, O. borealis and O. quercus were detected from A. alba for the first time. The composition of the fungal communities varied among the studied tree species and to a lesser degree among the beetle species. The spruce-infesting bark beetles were commonly associated with species of Leptographium s. l. and Ophiostoma s. str.; the larch-infesting bark beetles were often associated with Ophiostoma s. str. and Sporothrix, while the fir-infesting bark beetles were commonly associated with Ophiostoma s. str. and Graphilbum. The most commonly encountered fungal associates of the examined insects were (a) Grosmannia cucullata, G. piceiperda, Grosmannia sp. 1, Ophiostoma macroclavatum and O. piceae with the spruce-infesting bark beetles; (b) O. pseudocatenulatum and Sporothrix sp. 1 with the larch-infesting bark beetles; and (c) O. piceae, Ophiostoma sp. 2 and Graphilbum sp. 2 with the fir-infesting bark beetles. The differences in fungal associates among the bark beetle species occurring on P. abies, L. decidua and A. alba could be linked to the different habitats that these beetles occupy.     

Ecological integrity of remnant montane forests along an urban gradient in the Sierra Nevada

Urban development typically has extensive and intensive effects on native ecosystems, including vegetation communities and their associated biota. Increasingly, urban planning strives to retain elements of native ecosystems to meet multiple social and ecological objectives. The ecological integrity of native forests in an urbanizing landscape is challenged by a myriad of impacts, such as forest management and invasive species. Environmental protection efforts in the Lake Tahoe basin, spanning the California/Nevada border in the Sierra Nevada mountains, over the past half century have resulted in the retention of thousands of parcels of remnant native forest located throughout the urbanizing landscape. The basin landscape provides an opportunity to evaluate the effects of land development on the composition and structure of remnant native forests along a gradient of urbanization. We sampled 118 sites located in remnant forests in the lower montane zone surrounded by 0–70% development. We also sampled forest structure in the landscape surrounding 75 of these sites to evaluate the contribution of remnant forests to the retention of native forest elements in the larger landscape. We characterized plant species composition and cover, vertical structure, and the density of trees, snags, and logs, as well as levels of ground disturbance and human activity. We found that remnant native forests retained much of their compositional and structural character along the development gradient, including large tree density, total canopy cover, and plant species richness. Notable exceptions were reductions in the density and decay stage of snags and logs, and the density of understory trees. We also observed increases in the richness and cover of herb and grass species and increases in the number of exotic plant species. In contrast, structural complexity was reduced in the landscape surrounding forest remnants in all measures except large tree density. We conclude that remnant native forests contribute significantly to maintaining native species in an urbanizing landscape, and that land conservation practices have an important role to play in protecting native forest ecosystems.     

Mixed forests and ecosystem services: Investigating stakeholders' perceptions in a case study in the Polish Carpathians

Mixed forests are thought to provide a wide range of ecosystem services for human well-being and their effectiveness, compared to monocultures, is broadly recognized in the literature. Mixed forests may increase the multifunctionality, providing a wide range of ecosystem services such as hazard protection, carbon sequestration, nature conservation and landscape values. Before undertaking a process of conversion of monocultures into mixed forests it is important to learn about perceptions of local stakeholders for mixed forests in comparison to monocultures, in order to understand their needs and identify possible sources of conflicts. In the present work, we investigate the personal perceptions about the effectiveness of mixed forests when compared to monocultures, in terms of provisioning of ecosystem services, with the aid of an ordered logit model. In addition, we highlight the fact that belonging to a particular category of organized stakeholders contribute to perceive mixed forests positively, compared to non-organized local dwellers. Results show that people acknowledging the importance of some non-productive forest ecosystem services are more likely to prefer mixed forests. Moreover, personal attitudes towards ecosystem services seem to be much more related to the degree of preference for mixed forests than other socio-economic variables, such as gender and education. Finally, another evidence of this contribution is that belonging to a precisely defined group of stakeholders considerably increases the probability to prefer mixed forests, compared to ordinary citizens.     

Plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern China

The effects of anthropogenic disturbances on forest structure and plant diversity of secondary forest ecosystems were evaluated based on the classification by site factors in the montane regions of northeastern China. Forty-five sample plots containing 720 sub-plots of overstory species (8 m × 8 m), 1,440 quadrats of understory species (2 m × 2 m), and 1,440 quadrats of herbaceous layer species (1 m × 1 m) were clustered into five groups (G1, G2, G3, G4 and G5) by site variables with Hierarchical Cluster Analysis. Meanwhile, the disturbance levels corresponding to the five groups were determined according to the factors influencing human disturbances (D0-G2, D1-G1, D2-G3, D3-G5, and D4-G4). Species diversities of overstory, understory, herbaceous layer and overall species were evaluated using species number, Margalef index, Pielou index, Shannon–Wiener index, and Simpson index; and β-diversities (Whittaker index, Cody index). Basal area of stands exhibited a decreasing trend along the disturbance level due to a gradual increase in the extraction of timber by the human disturbances. The indices of species diversity suggested that overstory and understory species were distributed evenly among the groups or disturbance levels. There were no absolutely dominant tree species in the secondary forest ecosystems. The differences in site factors and the current disturbance intensities were not intense enough to lead to loose changes in overstory and understory species. The species diversity indices exhibited the maximum values at D3 (G5) for herbaceous layer species; this may suggest that the current disturbance intensities were intense enough to lead the changes of herbaceous layer species. Three rare and endangered species (Juglans mandshurica, Fraxinus mandshurica and Acanthopanax senticosus) were found within the secondary forests. These rare and endangered species appeared in each clustered group or disturbance level, which suggested that the current disturbance intensity in the study area was not strong enough to influence the distribution of rare and endangered species. The current disturbances in the secondary forests may not lead to a decrease in stability and complexity of the overstory and understory species, but the higher disturbance level may be intense enough to change the habitat fitness for the herbaceous species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized authors.     

Canopy gaps in an old-growth fir-beech forest remnant of Western Carpathians

The old-growth forest remnants of Western Carpathians provide a unique possibility to study the disturbance regimes of forest ecosystems without human influence. This study investigated the gap dynamics in beech-dominated old-growth forest Badínsky prales in Central Slovakia. Considering the decline of silver fir in last decades, the study analyzed the main characteristics of disturbance regime with the emphasis on the role of fir. On a 5-ha research plot, the dominant tree species was beech, the proportion of fir reached about 10%. However, a significantly higher proportion of fir (>30%) was observed in the coarse woody debris. In total, 45 canopy openings were recorded. Canopy gaps and expanded gaps covered 11.3 and 37.9% of the forest area, respectively. Despite the highest frequency of small gaps <100 m², their proportion of the overall gap area reached only 20%, what suggests the important role of intermediate and large gaps in the gap dynamics as well. The analysis of gapmakers’ crown projections confirmed a rather low contribution of fir (14.6%) to the gap formation despite its relatively intensive mortality. A high variability of the next generation age between the gaps (6–44 years) was recorded what suggests a large temporal variation of the disturbance events. The lateral expansion of adjacent trees was found to be the determining process for the closure of small canopy openings. The intermediate and large gaps are more likely closed by the height growth of natural regeneration and understory trees that are present on the majority of the area.     

Impact of timber harvesting on carbon storage in montane forests of central Mexico

New Forests - Cut stumps are the legacy of forest harvesting and allow for the estimation of carbon loss from the ecosystem. The objective of this study was to estimate aboveground carbon storage...