Composition Of Forest Ecosystems Research Articles

Использование лесных ресурсов и организация лес- ного хозяйства в Северном Предуралье во второй половине XIX ‒ начале XX века

Forestry practices, including large-scale logging, have led to substantial and long-term alterations in the structure and composition of forest ecosystems. To understand the extent of these changes and identify remaining intact forests, a comprehensive land-use history is crucial. This helps reconstruct and identificate previous impacts, considering their magnitude and extent. Based on archival documents introduced into scholar discussions for the first time, the paper offers a precise comprehension of the extent of forestry growth and the organization of state forestry in the Northern Ural region. The study area covers the basins of the Kolva, a tributary of the Kama, which flows into the Caspian Sea, and the Upper Pechora, which flows into the Arctic Ocean. During the 19th century, this area had a sparse population and no road network. Today, it is a large, intact forest, with a portion designated as a UNESCO World Heritage Site called 'Virgin Forests of the Komi'. The governance of the forest has undergone several changes. In the 1840s, the Cherdynsky district Estate was established in the Cherdyn municipality, covering an area of over 2.8 million hectares. In 1870, the region was split into Cherdynsky and Kolvinsky forest management departments. In 1894, the Kolvinsky district was again separated into three: Kolvinsky, Chusovsky, and Verkh-Pechersky departments. The forests in the Pechora River basin were appealing for foreign export markets. However, logging did not commence due to various reasons. The primary consumers of forest resources were the local inhabitants, who actively constructed boats of various sizes. For example, in 1876, around 1,800 trees of different sizes were cut down to build 15 vessels. The collection of construction timber annually in the 1880s did not surpass 10,000 trees. During the latter half of the 19th century, the mass logging of trees might have begun in the upper Pechora region. This was evidenced by the leasing of vast forested areas in the late 1890s by the Alfred Lidbeck’s Swedish company, with intentions to cut down approximately 2 million construction trees. Nevertheless, logging was not initiated due to the challenge of timber floating and the inadequacy of the workforce. During the same period, a metallurgical plant was established on a tributary of the Pechora. The company planned to cut down all forests along the rivers for fuel, but the factory ceased its operations after three years. The forests in the Kolva River basin provided the primary source of fuel for the salt production located on the Kama River. From the 1880s, between 22,000 to 30,000 cubic meters of firewood were collected annually. A significant amount of wood was employed in the construction of barges. By the end of the 19th century, the logging industry went through a reorientation. Logging activities for the harvest of saltwood and barge-building followed by the production of construction lumber for export to Volga markets replaced the focus on the logging industry, leading to approximately 50,000 log shipments yearly. Throughout the whole 19th century, the forests were left unexplored, without any management plans. There were no networks of roads in the area. Timber for building and barge construction was harvested selectively by landscape units. A few dozen trees of the required size were selectively harvested from each hectare. Clear-cutting sites for the harvesting of salt-wood were located no further than 1 to 3 kilometers from the majority of rafting rivers. The preserved archival materials are crucial for understanding past impacts and should be integrated into contemporary ecological research.

Paired acoustic recordings and point count surveys reveal Clark's nutcracker and whitebark pine associations across Glacier National Park.

Global declines in tree populations have led to dramatic shifts in forest ecosystem composition, biodiversity, and functioning. These changes have consequences for both forest plant and wildlife communities, particularly when declining species are involved in coevolved mutualisms. Whitebark pine (Pinus albicaulis) is a declining keystone species in western North American high-elevation ecosystems and an obligate mutualist of Clark's nutcracker (Nucifraga columbiana), an avian seed predator and disperser. By leveraging traditional point count surveys and passive acoustic monitoring, we investigated how stand characteristics of whitebark pine in a protected area (Glacier National Park, Montana, USA) influenced occupancy and vocal activity patterns in Clark's nutcracker. Using Bayesian spatial occupancy models and generalized linear mixed models, we found that habitat use of Clark's nutcracker was primarily supported by greater cone density and increasing diameter of live whitebark pine. Additionally, we demonstrated the value of performing parallel analyses with traditional point count surveys and passive acoustic monitoring to provide multiple lines of evidence for relationships between Clark's nutcracker and whitebark pine forest characteristics. Our findings allow managers to gauge the whitebark pine conditions important for retaining high nutcracker visitation and prioritize management efforts in whitebark pine ecosystems with low nutcracker visitation.

Comparative study of the analytical hierarchy process, frequency ratio, and logistic regression models for predicting the susceptibility to Ips sexdentatus in Crimean pine forests

The six-toothed bark beetle Ips sexdentatus is one of the most important pests of coniferous trees that can cause extensive tree mortality, and change the structure and composition of forest ecosystems. Many abiotic and biotic factors affect the infestation of bark beetles. Early detection of forest stands predisposed to bark beetle infestations will benefit from reducing the impacts of possible infestations. The study focused on the production and comparison of Ips sexdentatus susceptibility maps using the analytical hierarchy process (AHP), frequency ratio (FR), and logistical regression (LR) models. The research was carried out in the Crimean pine forests of the Taşköprü Forest Enterprise in Kastamonu City in the Western Black Sea region of Türkiye. The eight main criteria used to produce the map were the stand structure, site index, crown closure, stand age, slope, elevation, maximum temperature, and solar radiation. The map of the infested stands was used for the models' validation. Crown closure was determined as the one of the most important factors in all three models. The receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to determine the accuracy of the maps. The validation results showed that the AUC for the FR model was 0.747, for the AHP model was 0.716, and for the LR model was 0.638. The results revealed that the FR model was more accurate than the other models in producing an I. sexdentatus susceptibility map. Besides, the AHP model was also reasonably accurate. This study could help decision makers to produce bark beetle susceptibility maps easily and rapidly so they can take the necessary precautions to slow or prevent infestations.

Ormanlarda iklim değişikliğinin etkilerinin belirlenmesinde bazı önemli parametreler: Cerle planlama birimi örneği, Antalya, Türkiye

Climate change is one of the most detrimental issues of the earth in this century. It is evident that a change in climate parameters would affect considerably the entire global ecosystem’s environment. On the other hand, different forest related parameters such as natural disaster occurrence or land cover change of forest ecosystems could also help to understand the effects of climate change besides climate parameters such as temperature, precipitation or relative humidity. Therefore, in this study, selected parameters describing climate change were tried to display in a Mediterranean forest planning unit called “Cerle” located in Antalya. Firstly, trend analysis was carried out using climate parameters in the selected study area to detect the amount of climate change. Then, different natural disaster occurrences such as forest fire, windstorm, insects and pest attack evolution were displayed over a period of 30 to 50 years. Spatiotemporal changes for the same period were also tried to be demonstrated, based on historical and actual maps to identify the impact of climate change on the structure and composition of forest ecosystems. In brief, Mann-Kendall test results showed significant increasing trends in annual mean temperature and precipitation. Moreover, the natural development of crimean pine as a result of land use change analysis, as well as the increasing frequency of wildfires and windstorm leading to salvage cutting have been interpreted as the impact of climate change. It is concluded that changes in selected climate parameters are very important to display the climate change digitally. The outputs of this study could help in future forest management planning decisions and determination of silvicultural prescriptions. Furthermore, the obtained results might be the basis for the integration of climate change to forest management planning related to future climate projections and scenarios.

Positive relationship between species richness and aboveground biomass in Kumaun Himalayan forest

Understory vegetation is an important part of forest ecosystem which affect the physical and chemical properties of soil, quality and quantity of forest litter and water storage capacity of litter soil layer. Thus, the influence of soil nutrients on the understory species composition of forest ecosystem cannot be ignored. The authors set 15 typical plots with area of 1 × 1 m in chir pine (Pinus roxburghii Sarg.), oak (Quercus leucotrichophora A. Camus)—chir pine mixed and oak–cypress (Cupressus torulosa D. Don) mixed forest. Chemical properties of the soil were analyzed at 0–10 cm, 10–20 cm and 20–30 cm in all the selected forest types. Phytosociological and diversity parameters were also calculated for each forest type. The present study reveals that carbon, nitrogen, pH and phosphorus are the most important environmental drivers which influence understory species composition. Plant species richness significantly correlated with species composition. To maintain the diversity and structure of ecosystems we should consider the co-evolution of both vegetation and soil. Further studies on climate and microorganism are needed to further explore the interactive relationships among vegetation and soil properties.

Responses of non-structural carbohydrates content in leaves of different plant species in Pinus tabuliformis plantation to nitrogen addition

Through its impact on plant physiological processes, global nitrogen deposition could alter the structure and composition of forest ecosystems. However, we are not clear about the effects of N deposition on leaves' non-structural carbohydrate (NSC) content of different plants. In this study, we compared the responses of NSC contents in seven different plant species to four nitrogen addition levels (0, 3, 6, and 9 g N·m-2·a-1, referred to as N0, N3, N6, N9, respectively), including Pinus tabuliformis, Quercus liaotungensis, Lonicera japonica, Spiraea salicifolia, Rosa xanthina, Rubia cordifolia, and Carex lanceolata in an artificial Pinus tabuliformis forest located in the hilly area of the Loess Plateau. The contents of soluble sugar and starch varied greatly in plant species, with the highest variability in R. xanthina and the lowest in S. salicifolia and C. lanceolata. There were significant differences in the responses of soluble sugar and starch contents to nitrogen addition among different species. Under N6 treatment, the variability of soluble sugar and starch in R. cordifolia came the first while S. salicifolia exceeded all other species under N3 and N9 treatments on that rating. The specific species with the lowest variability of soluble sugar and starch contents differed with nitrogen addition levels. With the increases of nitrogen addition rate, the soluble sugar content of P. tabuliformis and C. lanceolata exhibited a continuous rising trend, an opposite trend of S. salicifolia, while that of Q. liaotungensis, L. japonica, and R. xanthina decreased first and then increased, reaching its minimum at N6 treatment. The response of R. cordifolia to nitrogen addition was complex. With respect to starch content, P. tabuliformis, L. japonica and C. lanceolata showed a continuous increase trend with nitrogen addition whereas S. salicifolia decreased first and then increased, troughing at N3 treatment. R. xanthina and R. cordifolia responded complicatedly yet Q. liaotungensis appeared less responsive. Under N addition treatments, there was no explicit correlation between NSC content and soil physical and chemical properties including pH, organic carbon, total nitrogen and phosphorus. There was a significant influence of those soil properties on the soluble sugar/starch ratio under N0 or N3 treatment. Our results indicate that different species have obviously different responses of NSC to nitrogen addition. Future research concerning the impacts of global nitrogen deposition on forest ecosystems should take into account the target species, especially to pay attention to the responses of vegetation with different life forms.

Climate change, woodpeckers, and forests: Current trends and future modeling needs.

The structure and composition of forest ecosystems are expected to shift with climate‐induced changes in precipitation, temperature, fire, carbon mitigation strategies, and biological disturbance. These factors are likely to have biodiversity implications. However, climate‐driven forest ecosystem models used to predict changes to forest structure and composition are not coupled to models used to predict changes to biodiversity. We proposed integrating woodpecker response (biodiversity indicator) with forest ecosystem models. Woodpeckers are a good indicator species of forest ecosystem dynamics, because they are ecologically constrained by landscape‐scale forest components, such as composition, structure, disturbance regimes, and management activities. In addition, they are correlated with forest avifauna community diversity. In this study, we explore integrating woodpecker and forest ecosystem climate models. We review climate–woodpecker models and compare the predicted responses to observed climate‐induced changes. We identify inconsistencies between observed and predicted responses, explore the modeling causes, and identify the models pertinent to integration that address the inconsistencies. We found that predictions in the short term are not in agreement with observed trends for 7 of 15 evaluated species. Because niche constraints associated with woodpeckers are a result of complex interactions between climate, vegetation, and disturbance, we hypothesize that the lack of adequate representation of these processes in the current broad‐scale climate–woodpecker models results in model–data mismatch. As a first step toward improvement, we suggest a conceptual model of climate–woodpecker–forest modeling for integration. The integration model provides climate‐driven forest ecosystem modeling with a measure of biodiversity while retaining the feedback between climate and vegetation in woodpecker climate change modeling.

Variation in the performance and thermostability of photosystem II in European beech (Fagus sylvatica L.) provenances is influenced more by acclimation than by adaptation

The assisted migration of resistant seeds and seedlings may be a key to mitigating the effects of climate change on the productivity and composition of forest ecosystems. These efforts require an understanding of the intraspecific variability in the response of trees to extreme weather events such as heat waves. In this study, we assessed the geographical patterns of photosystem II (PSII) performance and thermostability in European beech (Fagus sylvatica L.) and whether intraspecific differences are associated with climate of origin. Two provenance trials with starkly contrasting climates were used for this study. Leaves were sampled both before and after natural heat stress exposure. Rapid chlorophyll fluorescence kinetics was used to evaluate PSII performance and PSII thermostability after simulated heat stress. The performance of PSII at 30 °C, which is still considered a non-damaging temperature, was generally slightly better at the warmer location than at the colder location. The populations originating closer to the Slovenian refugium, as well as those growing closer to their site of origin, showed better performance of PSII but not greater thermostability. The effect of simulated heat stress was much stronger in the colder plots compared to the warmer plots, but only for previously stressed trees. Likewise, we found indicators of geographical patterns of thermotolerance as well as relationships between thermotolerance and climate of origin mostly for trees exposed to natural heat. While the origin of provenances partly explained the variation among provenances, acclimation driven by climate played a major role in the response to heat stress. In beech, PSII seems to have a potential for coping with high temperature.

Insights into Ecological Effects of Invasive Plants on Soil Nitrogen Cycles

The increasing degree of plant invasion is an expanding problem that affects the functioning and composition of forest ecosystems with increasing anthropogenic activities, particularly soil nitrogen (N) cycles. Numerous studies have revealed that one of the main factors for successful plant invasion is that plants could pose significant effects on soil N cycles via direct and/or indirect ways, such as changes in soil microbial communities, litter decomposition rates, and/or soil physicochemical properties. We thereby summarize the ecological effects of invasive plants on soil N cycles, including the aforementioned changes, to understand the mechanism of successful invasion. We also discuss the needs for further research on the relationship between invasive plants and soil N cycles.

Soil‐mediated effects of invasive ungulates on native tree seedlings

Summary Invasive browsing ungulates can have strong impacts on the structure and composition of forest ecosystems, particularly where ungulates are not native ecosystem components as in New Zealand. Ungulate impacts on plant communities have been considered mostly from an above‐ground perspective. However, understanding below‐ground effects of these invasive herbivores is critical as they may drive feedbacks to above‐ground ecosystem components. We measured growth responses of seedlings of five common tree species in a greenhouse experiment in soils collected from 26 plots fenced to exclude invasive ungulates for at least 17 years and from paired, unfenced control plots. We then further investigated soil‐mediated effects of ungulates on one tree species, Melicytus ramiflorus, by partitioning these effects into soil abiotic and biotic components, as well as measuring arbuscular mycorrhizal fungal (AMF) root infection. Biomass of seedlings of all five species was greater in soils from within exclosures, although this was only significant for two species. These soil‐mediated effects were partially driven by changes in physical and chemical soil properties; soil bulk densities were lower inside exclosures than in controls. Effects of invasive ungulates on seedling biomass of M. ramiflorus were positively related to effects on per cent AMF root infection. The biomass of M. ramiflorus seedlings was positively related to the AMF infection of its roots, which in turn was related to greater organic matter content and lower bulk density of soils from within exclosures. Results for M. ramiflorus indicated that soil‐mediated effects of ungulates on seedling biomass were of abiotic origin, but were mediated by the biotic soil component, that is, through effects on AMF. Synthesis. Invasive herbivores may potentially impact on plant performance and community structure not only directly but also indirectly through influencing soil abiotic and biotic properties. Our results show that shifts in plant–soil interactions and feedbacks represent important but understudied pathways by which invasive ungulates can have wide‐ranging impacts on forest ecosystems. Future studies should consider the importance of soil‐mediated effects of invasive ungulates relative to direct effects of herbivory.

Effects of nitrogen addition on litter decomposition, soil microbial biomass, and enzyme activities between leguminous and non‐leguminous forests

AbstractAnthropogenic nitrogen (N) deposition is an expanding problem that affects the functioning and composition of forest ecosystems, particularly the decomposition of forest litters. Legumes play an important role in the nitrogen cycle of forest ecosystems. Two litter types were chosen from Zijin Mountain in China: Robinia pseudoacacia leaves from a leguminous forest (LF) and Liquidambar formosana leaves from a non‐leguminous forest (NF). The litter samples were mixed into original forest soils and incubated in microcosms. Then, they were treated by five forms of N addition: NH4+, NO3−, urea, glycine, and a mixture of all four. During a 6‐month incubation period, litter mass losses, soil microbial biomass, soil pH, and enzyme activities were investigated. Results showed that mixed N and NO3−‐N addition significantly accelerated the litter decomposition rates of LF leaves, while mixed N, glycine‐N, and urea‐N addition significantly accelerated the litter decomposition rates of NF leaves. Litter decomposition rates and soil enzyme activities under mixed N addition were higher than those under single form of N additions in the two forest types. Nitrogen addition had no significant effects on soil pH and soil microbial biomass. The results indicate that nitrogen addition may alter microbial allocation to extracellular enzyme production without affecting soil microbial biomass, and then affected litter decomposition process. The results further reveal that mixed N is a more important factor in controlling litter decomposition process than single form of N, and may seriously affect soil N cycle and the release of carbon stored belowground.

Tree rings indicate different drought resistance of a native ( Abies alba Mill.) and a nonnative ( Picea abies (L.) Karst.) species co-occurring at a dry site in Southern Italy

Climate changes induced by the anthropogenic alteration of the atmospheric radiative balance are expected to change the productivity and composition of forest ecosystems. In Europe, the Mediterranean is considered one of the most vulnerable regions according to climatic forecasts and simulations. However, although modifications in the inter-specific competition are envisaged, we still lack a clear understanding of the ability of the Mediterranean vegetation to adapt to climate changes. We investigated how two co-occurring tree species commonly used in afforestation programmes, the native Abies alba Mill. and the nonnative Picea abies L. Karst., adapt to climate change by assessing their growth performance and physiological responses in relation to past climate variability. Growth was addressed by analysing tree-ring width and carbon and oxygen stable isotopes. Statistical relationships between isotopic value and monthly climate data suggest that the two species underwent ecophysiological adaptation to Mediterranean climatic constraints. These adaptations are also expressed in the ring-width data. Based on the carbon isotope ratio reflecting the stomatal response to drought, we found that the precipitation in the first period of the growing season, i.e. early spring, is a major factor influencing the annual growth of A. alba, which although native, proved to be sensitive to drought. P. abies, on the other hand, showed a higher tolerance to summer drought stress. These findings should help define criteria for sustainability and effective forest conservation in the Mediterranean region.

Effect of Siberian tree species on N2O production and consumption

The effect of six Siberian tree species on two stages of denitrification-N2O production and consumption-was studied. Broadleaf species (aspen and birch) proved to have lower rates of N2O consumption compared to coniferous species. The factors influencing production and consumption of N2O were also evaluated. The replacement of coniferous forests with broadleaf trees will double the N2O/N2 ratio in the denitrification end-products. Doubled N2O emission from Siberian forest soils to the atmosphere can be expected due to changes in tree species composition of forest ecosystems even without considering changes in water and temperature regimes in soil.

Interspecific interactions of ungulates in European forests: an overview

Mammalian herbivores vary in the degree to which they browse, graze and cause physical disturbance, and so vary in the effects they have on the structure and composition of forest ecosystems. To create predictive models of the interactions of forest ecosystems with herbivore communities, an appreciation of the interactions between the species of herbivore themselves is necessary. This paper reviews interspecific interactions of ungulates, methods used in studying them, and seeks to identify areas to which future research should be directed in the context of European forest systems. Methods that have been used to provide information on interactions include: comparative resource studies, niche theory, physiological and anatomical analyses, modeling and foraging theory, and population studies. The most commonly reported types of interactions appear to be competition and facilitation. Behavioural and social interactions between species are potentially important, but evidence for these is scarce and often anecdotal. It is suggested that there may be considerable potential for ungulates to interact in European forests which are often significantly altered from their natural state. Future research should aim at refining the theoretical understanding of interspecific interactions, particularly between ungulates with different feeding ecologies. The roe deer ( Capreolus capreolus) has a major impact on forest ecosystems and is increasing its range throughout Europe. However, there is evidence that it may be displaced or out-competed by a number of ungulate species, and it is suggested as being research priority to quantify these effects.

Prescribed Fire — Its Place in Reforestation

Forest fires have played an important role in determining the type and composition of forest ecosystems in the temperate region of North America. The close association between fires and forest ecosystems has helped the resource manager to interpret the significance of fire in reforestation, which in turn has induced him to use burning for this specific purpose. Until very recently, however, most of the burns in Canada have been carried out primarily for slash-fire-hazard reduction. Considerations in the planning and use of prescribed fire for hazard reduction and reforestation are inextricably linked and sometimes complementary. In addition to protection and reforestation objectives, prescribed burning should find wide application in the management of wildlife habitats and watersheds. Recommendations are made to assist resource managers and the public in appreciating more fully the present and potential role of fire in the forest ecosystems.