Different Types Of Forest Ecosystems Research Articles

Forest Community Spatial Modeling Using Machine Learning and Remote Sensing Data

This study examines the application of unsupervised classification techniques in the mapping of forest vegetation, aiming to align vegetation cover with the Braun-Blanquet classification system through remote sensing. By leveraging Landsat 8 and 9 satellite imagery and advanced clustering algorithms, specifically the Weka X-Means, this research addresses the challenge of minimizing researcher subjectivity in vegetation mapping. The methodology incorporates a two-step clustering approach to accurately classify forest communities, utilizing a comprehensive set of vegetation indices to distinguish between different types of forest ecosystems. The validation of the classification model relied on a detailed analysis of over 17,000 relevés from the “Flora” database, ensuring a high degree of accuracy in matching satellite-derived vegetation classes with field observations. The study’s findings reveal the successful identification of 44 forest community types that was aggregated into seven classes of Braun-Blanquet classification system, demonstrating the efficacy of unsupervised classification in generating reliable vegetation maps. This work not only contributes to the advancement of remote sensing applications in ecological research, but also provides a valuable tool for natural resource management and conservation planning. The integration of unsupervised classification with the Braun-Blanquet system presents a novel approach to vegetation mapping, offering insights into ecological characteristics, and can be good starter point for sequestration potential of forest communities’ assessment in the Republic of Tatarstan.

Effects of Thinning on Carbon Storage in a Mixed Broadleaved Plantation in a Subtropical Area of China

Forest thinning is a widely used silvicultural method in forest management and has complex effects on carbon sequestration in different types of forest ecosystems. The present study examined the short-term effects of different thinning intensities on carbon storage in an 11-year-old mixed broadleaved plantation. The results partially supported that different thinning intensities have varying impacts on carbon storage in different parts of forest ecosystems. The main results were as follows: (1) The effect of thinning on promoting the growth of fast-growing tree species (Michelia macclurei Dandy and Schima superba Gardn. et Champ.) was earlier than that of slow-growing tree species (Castanopsis hystrix Miq.). (2) A greater thinning intensity conferred greater effects on promoting the tree biomass carbon growth, litter carbon storage, and understory plant diversity, in the order of 41%~50% > 31%~40% > 20%~30%, but these values were lower than those for the unthinned plots. (3) The soil carbon storage declined most in the 41%~50% thinned plots, due to the reduced carbon storage in the humus layer. (4) The 20%~30% thinning intensity promoted carbon sequestration in the short term in the mixed broadleaved plantation. The results suggested that a lower thinning intensity promoted carbon sequestration in the short term, a greater thinning intensity reduced carbon storage at first, but the negative effect on carbon storage exhibited trade-offs later by the growth of tree and understory plant biomass carbon and the accumulation of litter layer carbon.

New fungal non-pollen palynomorphs from moss polsters collected from the Białowieża Forest (NE Poland)

This paper reports on new, previously undescribed non-pollen palynomorphs (NPPs) of fungal origin preserved in moss polsters in a forest environment of a temperate zone. Modern NPPs were recovered from moss samples from 114 sites located in different types of forest ecosystems of Białowieża Forest, north-eastern Poland – a forest complex with a high degree of naturalness, similar to forests that covered large areas of Europe in the past.98 types of fungal NPPs were identified, of which 20 morphotypes presented here are considered new, not previously described. Half of the new remains could be identified to species or genus level, thereby conferring ecological indicator value to them. Each new, determined NPP can be a useful tool in environmental reconstructions.This study shows that moss polsters in forested areas contain many undescribed NPPs, the description and analysis of which can deliver additional ecological information about ecosystems.

Linking leaf δ15N and δ13C with soil fungal biodiversity, ectomycorrhizal and plant pathogenic abundance in forest ecosystems of China

Leaf δ15N and δ13C are important functional traits in biogeographic studies of forest ecosystems. However, little is known about their relationships with soil fungal biodiversity, ectomycorrhizal and plant pathogenic abundance at large scales. In this study, leaf and soil samples were collected from 33 forest reserves along a large range across China to explore the associations between leaf δ15N and δ13C and soil fungal biodiversity, ectomycorrhizal and plant pathogenic relative abundance, using molecular and stable isotope techniques. Leaf δ15N was significantly positively correlated with the soil fungal Shannon index, significantly negatively correlated with the relative abundance of plant pathogens, and significantly positively correlated with the relative abundance of ectomycorrhizas. Leaf δ13C was significantly positively correlated with the relative abundance of ectomycorrhizas and significantly inverted unimodal correlated with the relative abundance of plant pathogens. Soil–plant–microbial interactions may contribute to variations in leaf δ15N, δ13C, and soil fungal communities among different types of forest ecosystems. Temperature and precipitation were the main factors that affected large-scale latitudinal and longitudinal biogeographic patterns. Leaf δ15N was mainly affected by the relative abundance of ectomycorrhizal fungi and leaf δ13C was affected by the mean annual temperature and mean annual precipitation. Leaf δ15N and δ13C may be indicators that reflect soil fungal communities in forest ecosystems.

Bioaccumulation of potentially toxic elements within the soil-plant system in Central Balkan region: analysis of the forest ecosystem capacity to mediate toxic elements.

The accumulation of potentially toxic elements (PTEs) in terrestrial ecosystems has become a global concern, as PTEs may exert a wide range of negative impacts on forest's ecological state due to local or transboundary pollution. Forest vegetation and soil display great potential as means of coping with the accumulation mechanisms, absorption and dissolving the pollutants. Therefore, it is crucial to study the transfer of PTEs across these basic components of the forest ecosystem. Investigation on the PTEs concentrations in the soil-plant system in relatively non-polluted environment of Central Balkan National Park (Sredna Stara Planina Mountain) provides more information about the role of the forest patterns and soil properties for the bioaccumulation processes in the context of ecosystem services concept. In this paper, the transfer of PTEs in soil-plant system in relatively clean environment is studied in order to assess and map the ecosystem capacity of different types of forest ecosystems to mediate toxic elements. Based on in situ observations and sampling, the PTEs concentrations in soil and aboveground vegetation were analyzed. The potential of each forest type to reduce the impact of PTEs and bioaccumulation as an indicator of ecosystem service is also discussed. The GIS analysis supports the study by creating a common database and setting the basis for ecosystem services assessment. The generated maps represent areas where the forest ecosystems have the greatest capacity to provide related ecosystem service and mediate toxic elements. The bioaccumulation of PTEs in forest territories results in medium to low rates and higher supply capacity is not present at any spatial unit asthe accumulation process is focused in the soil. The obtained results highlight the ecological importance of soil in terms of acting as a buffer against pollution, especially in areas with intensive road traffic.

The effect of Indian summer monsoon on the seasonal variation of carbon sequestration by a forest ecosystem over North-East India

The Indian summer monsoon is one of the most important yet less understood synoptic processes on the Earth, characterized by an increased amount of rainfall over the entire Indian landmass. The different types of forest ecosystems existing over the Indian region offer a tremendous carbon sequestration potential useful for the global mitigation of climate change as predicted by the modelling studies. The monsoon results in a strong seasonality of the ecosystem-atmosphere carbon exchange due to the differential availability of two key controlling parameters of photosynthesis namely radiation and water. However, due to the sparsity of surface observations neither the carbon sequestration potential of these ecosystems nor its relation with the monsoon has been analysed comprehensively so far. This paper studies the ecosystem-atmosphere CO2 exchange at a tropical semi-evergreen moist deciduous forest and its relation with the monsoon over north-east India using the eddy covariance and associated meteorological measurements. In 2016, this ecosystem acts as a net source of atmospheric CO2 with net ecosystem exchange of 207.51 ± 157.37 gC m−2 year−1 and gross photosynthesis and ecosystem respiration of 2604.88 ± 179.43 and 2812.38 ± 22.05 gC m−2 year−1, respectively. The monsoon clouds are seen to introduce a bimodal pattern in the annual GPP record. The pre-monsoon and winter are the most and least favourable seasons for the photosynthetic CO2 uptake by this forest canopy. Additionally, the rate of increase of photosynthesis with evapotranspiration is maximum and minimum during the pre-monsoon and winter, respectively.

MONITORING ON FOREST ECOSYSTEMS BY USING SPACE-TEMPORAL ANALYSIS OF DIFFERENT TYPES AEROSPACE DATA

The following work presents results derived by space-temporal analysis of different types of aerospace data for environmental monitoring on the dynamics of the condition of the forest vegetation. Different indices (NDVI, NDWI) and indicators have been used for territories occupied by different types of forest ecosystems. A comparative analysis between optical and radar images have been conducted and results about the degree of correlation between the different generated indices from the tested areas are presented. Based on the performed different analysis and surveys and the results derived from them, an evaluation can be done for the following: for which territories occupied by specific forest vegetation are the most sensitive indices during the monitoring. The derived results could be used for monitoring and ecological assessment on forest resources management in regional and national action plans.

Forestry under Climate Change. Is Time a Tool for Sustainable Forest Management?

Changing climate conditions are known to influence forest tree growth response and the CO2 cycle. Dendroclimatological research has shown that the climate signal, species composition, and growth trends have changed in different types of forest ecosystems during the last century. Under current and demonstrated changes in climate variability at the geographic, regional, and local levels tree growth shows also variability and trends that can be non-stationary during time even at relatively short distance between sites. In forest planning and management, yield tables, site quality indices, age class, rate of growth, and spatial distribution are some of the most used tools and parameters. However, these methods do not involve climate variability during time although climate is the main driver in trends of forest and tree growth. Previous research warns about the risk that forest management under changing climatic conditions could amplify their negative effects. For example, changing climate conditions may impact on temperature and/or precipitation thresholds critical to forest tree growth. Forest biomass, resilience, and CO2 storage may be damaged unless forest planning and management implement the relationships between climate variability and trends of tree growth. A positive aspect is that, periods of favorable climate conditions may allow harvesting higher amount of wood mass and storing more CO2 than traditional planning methods. And, the average length of both favorable and adverse periods appears to occur within the validity period of a forest management plan. Here, we show a conceptual development to implement climate variability in forest management in the view of continuing the research.

Crossdating of disturbances by tree uprooting: Can treethrow microtopography persist for 6000 years?

Establishing disturbance frequencies in different types of forest ecosystems is an area of considerable research. We use several overlapping dating methods – robust repeated tree–censuses, dendrochronology and radiometric techniques (radionuclides 14C, 210Pb, 137Cs, 226Ra) – to date 302 pit-mounds, formed by uprooting, in 3 different forest ecosystems. Our research goal was to better understand the disturbance frequencies in these ecosystems and establish the potential longevity of treethrow mounds. At the same time, we tested the applicability of multiple dating methods in different kinds of stands, including two sites in Central Europe and one in the Great Lakes region, USA.We used tree-census data to establish the ages of the youngest (<37yr) uprooting events, 210Pb dating (including 137Cs and 226Ra) to date treethrow events younger than ca. 200years, dendrochronological dating for sites less than ca. 400years old, and radiocarbon dating for assumed older sites. In order to maximize the reliability of these age estimates, we compared the dates by evaluating different methods with maximal overlap – a method we call crossdating. Theoretically, our data provide (i) “minimum-limiting” ages of disturbance events, using dendrochronology, tree-censuses, 210Pb- and/or 14C-dating of samples from the organo-mineral sedimentation funnel within the treethrow pit, (ii) “real” ages of events, using dendrochronology, and/or (iii) “upper-real” or “maximum-limiting” ages of the events, using 14C-dating on remnants of uprooted trunks and charcoal from buried A-horizons in mounds.Responses in the radial growth of trees near by uprooting disturbances were usually detectable for 20years, and were specific to each region and tree species. Repeated tree-censuses (13,795 trees from 72.84ha) suggested that the ratio of bole breakages to uprootings was 2–3:1, and that the treethrow rotation period approximated 1250–1380years for some sites in Central Europe. At our European, beech-dominated sites, the maximal longevity of the treethrow microtopography was ca. 220years on the fine-textured Haplic Cambisols and exceeded 1700years on sandy-loam Entic Podzols. Finally, on the sand-textured Albic Podzols of northern Michigan, even greater longevities were achieved, with one mound returning a 14C age of 5260±30 BP (median of calibration age 4077 BC) – by far the oldest feature reported in the literature. Sedimentation rates in treethrow pits, calculated using the 210Pb technique, were 0.05–0.28cmyear−1 in the beech-dominated European forests, and 0.07–1.4cmyear−1 in the hardwoods of Michigan. Radiocarbon dating of fungal sclerotia in treethrow pits can also help inform the disturbance history.

A Hybrid Approach to the Valuation of Climate Change Effects on Ecosystem Services: Evidence from the European Forests

In this paper we present a systematic attempt to assess economic value of climate change impact on forest ecosystems and human welfare. In the present study, climate change impacts are downscaled to the different European countries, which in turn constitute the elements of our analysis. First, we anchor the valuation exercise in the Millennium Ecosystem Assessment (MEA) Approach and therefore the link between the different forest ecosystem goods and services, including provisioning, regulating and cultural services, human well-being and climate change. Second, climate change is operationalized by exploring the different storylines developed by the International Panel on Climate Change (IPCC) and applied, downscaled, for each of the European countries under consideration. Third, and bearing in mind the different nature of the benefits provided by the different types of forest ecosystems under examination, we shall explore different economic valuation methodologies so as to shed light on the magnitude of the involved welfare changes. According to the estimation results the four different IPCC scenarios, i.e. A1F1, A2, B1 and B2, are associated to different welfare impacts. First, these reveal to depend on both the nature of the forest ecosystem service. For example, cultural values reveal to be more sensitive to the four IPCC scenarios than the other ones, with the wood forest products being more resilient to climate change. Second, the distributional impacts of climate change on the provision of these goods and services do also depend on the geo-climatic regions under consideration. For the Scandinavian group of countries, B1 is ranked with the highest level of provision of carbon sequestration services, amounting to 46.3 billion dollars. In addition, we can see that cultural services provided by forest ecosystems have their highest levels in the Mediterranean countries, ranging from 8.4 to 9.0 million dollars, respectively in the B2 and B1 scenarios. Finally, we can see that the total value of wood forest products ranges between 41.2 and 47.5 million dollars for Central Europe to 5.4 and 7.2 million dollars in Northern Europe, respectively A1 and A2 scenarios. For this service, Mediterranean Europe provides a relatively weak role in the provision with values ranging from 6.4 million dollars in A1 scenario to 8.7 million dollars in the B2. In short, and to conclude, the valuation results (1) may contribute to a better understanding of the potential welfare loss in the context of climate change and the economic trade-offs between potential mitigation or adaptation strategies; and (2) confirm that climate change will be responsible for a re-distribution of welfare among the European countries, signalling the potential for a(n) agreement(s) among these same countries focus on the re-allocation of potential trade-offs among the countries.

Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

Abstract. Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE) in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS), based on the flux data obtained during June–August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR) differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max) at CBS under cloudy skies during mid-growing season (from June to August) increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt) ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD) and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP) and greater increase in ecosystem respiration (Re) at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in cloudiness is an important factor that should be included in evaluating regional carbon budgets under climate change conditions.

Comparative analysis of137Cs bioavailability in forest ecosystems of different type

A quantitative analysis of 137 Cs in forest soils in the long term after the Chernobyl NPP accident based on a 3 years (1996-1998) investigation is presented. Five sites with different trees composition and properties of soil were studied to identify factors determining radiocaesium transfer to trees and different under story species. The following parameters were investigated: 137 Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of under story vegetation and distribution of their root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137 Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. High level of heterogeneity of 137 Cs specific activity in different parts of tree, which is related to physiological peculiarities of their functions, has been shown. The data obtained have demonstrated a non-uniform character for 137 Cs distribution along trunks, which can be explained by radionuclide fixation by walls of xylem vessels and by changes in geometry along the tree trunk. It has been found that the radial distribution of 137 Cs in the tree trunk is dependent on the availability of 137 Cs in soil, which governs the transfer of this radionuclide via xylem sap, and on the properties of the xylem. The accumulation of 137 Cs by both trees and under story species was influenced by 137 Cs vertical distribution and availability in soil as well as by the root (mycelia) biomass distribution in different soil horizons. A bioavailability factor, which takes into account the above factors, is proposed for comparative analyses of 137 Cs transfer from soil to plants in different types of forest ecosystems.

Identification of processes governing long-term accumulation of 137Cs by forest trees following the Chernobyl accident.

The regularities of 137Cs distribution in trees (Pinus sylvestris and Betula pendula) growing in different types of forest ecosystems were investigated. High levels of heterogeneity of 137Cs activity concentrations in different parts of the trees, resulting from their varied metabolism have been shown. The data obtained demonstrate a non-uniform character of 137Cs distribution along the trunks, which can be explained by radionuclide fixation by the xylem vessel walls and by geometry changes along the tree trunk. It has been found that the radial distribution of 137Cs in the tree trunk is dependent on the availability of 137Cs in soil, which governs the transfer of this radionuclide via xylem sap and on the properties of the xylem. The accumulation of 137Cs by trees was influenced by the vertical distribution and availability of 137Cs in the soil as well as by the root biomass distribution in different soil horizons. A bioavailability factor, which takes into account the vertical distribution of radiocesium in soil, bioavailability of this radionuclide and distribution of root biomass in different soil horizons is proposed for comparative analyses of 137Cs transfer from soil to trees in different types of forest ecosystems.

137Cs availability for soil to understory transfer in different types of forest ecosystems

A quantitative analysis of 137Cs bioavailability in forest soils in the long term after the Chernobyl NPP accident based on a 3-year (1996–1998) investigation is presented. Five forest sites with different trees, composition and properties of soil were studied to identify factors determining radiocaesium transfer to different understory species. The following parameters were investigated: 137Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of understory vegetation and distribution of root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. A linear dependence between aggregated transfer factors for different species and groups of species of understory vegetation and exchangeable and available fractions of radiocaesium in soil was found. The vertical distribution of 137Cs activity, percentage of exchangeable radiocaesium in each horizon of litter and soil, as well as distribution of root systems (mycelia) over the soil profile are key factors governing variations in the availability of 137Cs for transfer to all forest understory components.