Showing papers on "Undergrowth published in 2021"

Comparison of Soil Properties, Understory Vegetation Species Diversities and Soil Microbial Diversities between Chinese Fir Plantation and Close-to-Natural Forest

Abstract: With the continuous increase in plantation areas, the reduction of natural forest areas, and the unreasonable management of plantations by human beings, the service function of forest ecosystems has gradually reduced. Therefore, close-to-natural forestry has become important for the sustainable development of modern forestry. However, the differences in soil properties, enzyme activities, microbial diversities, and undergrowth vegetation species diversities have not been systematically explained for Chinese fir (Cunninghamia lanceolata). How do these indicators interact? The purpose of this paper was to study the difference in soil properties and biodiversity in different aged Chinese fir plantations and close-to-natural forests to explore their interactions and to provide direction for close-to-nature management. The results showed that the above indicators were significantly different in different aged Chinese fir plantations, soil pH, organic matter, total nitrogen, total phosphorus, total potassium, alkali-hydrolyzed nitrogen, available phosphorus concentrations, and urease activities in close-to-natural forests were significantly higher than plantations. It is worth mentioning that the richness of undergrowth vegetation species diversity (especially shrubs) and soil microbial diversities (especially fungi) in the close-to-natural forests were obviously higher than those in plantations. The correlation analysis results showed that the diversity of shrub species with respect to soil properties presented a higher correlation than herb species, the diversity of fungi with respect to soil properties presented a higher correlation than that observed for bacteria, and the diversity of fungi were significantly correlated with the diversity of undergrowth vegetation species diversities, but the correlation between bacteria and undergrowth vegetation species diversities was not significant. Our results suggest that the above factors are fundamental factors for the transformation of Chinese fir plantations to close-to-natural forests. To realize close-to-natural forestry, we must change the tree structure, combine the difference of those factors in different aged plantations, restore undergrowth vegetation species diversity, and thus improve microbial diversity and increase decomposition, transformation, and improvement of soil properties.

Grow slowly, persist, dominate-Explaining beech dominance in a primeval forest.

Abstract: Being able to persist in deep shade is an important characteristic of juvenile trees, often leading to a strong dominance of shade-tolerant species in forests with low canopy turnover and a low disturbance rate. While leaf, growth, and storage traits are known to be key components of shade tolerance, their interplay during regeneration development and their influence on juveniles' survival time remains unclear. We assessed the ontogenetic effects of these three traits on the survival time of beech (Fagus sylvatica), and Norway and sycamore maples (Acer pseudoplatanus, Acer platanoides) in a primeval beech forest. Biomass allocation, age, and content of nonstructural carbohydrates (NSC) were measured in the stems and roots of 289 seedlings and saplings in high- and low-vitality classes. Saplings experienced a trade-off between absolute growth rate (AGR) and storage (NSC) as the leaf area ratio (LAR) decreases with biomass development. High LAR but low AGR and low NSC corresponded to beech with a marked ability to persist in deep shade while awaiting canopy release. In turn, a comparably small LAR in combination with a high AGR and higher storage (NSC), as observed in Norway maple and sycamore maple, reduced sapling survival time, thus offering an explanation for beech dominance and maple disappearance in the undergrowth of old-growth beech forests.

The importance of livestock grazing at woodland-grassland interface in the conservation of rich oakwood plant communities in temperate Europe

Abstract: Traditional husbandry fostered rich semi-open oakwood communities composed of forest and non-forest species. In the eastern Carpathian region, silvo-pastoralism was commonplace by the mid-1900s. This study aimed to determine the state of the preservation of the ecotonal character of grassland-woodland interfaces in formerly pastured cultural landscapes of SE-Polish Carpathian foothills and W-Ukrainian Ciscarpathia in the context of land-use change. In the first region, despite the long-lasting history of forest grazing amongst mainly arable land, the post-WWII collapse of husbandry and the imposed ban on forest grazing, has led to swift development of dense undergrowth and establishment of impermeable ecological woodland-open habitat barrier. As a result, former silvo-pastoral oakwoods developed the features of the Tilio-Carpinentum forest community although some forest species have not yet moved in due to their poor dispersibility. The much younger oakwoods in the Ukrainian study region are remnants of the sparsely treed grasslands, some of which had been ploughed in the mid 20th century. Their semi-open canopy structure, maintained through repetitive grass burning, contributes to the communities ecotonal character, but without regular livestock-led plant “spill-over” from the grassland, the oakwoods remain species-poor. The restoration of species-rich semi-open oak woods requires “unsealing” the forest-grassland interface, reducing the degree of canopy closure, and opening that zone up to extensive grazing—an important seed dispersal vector.

Dynamics of Tree and Shrub Vegetation in the Eastern Sayan Mountain Tundra

Abstract: Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study, dendrochronological and GIS technologies have been used to evaluate shifts in the upper distribution limits of trees and shrubs in the Eastern Sayan Mountains. The results show that upward expansion along the altitudinal gradient and increase in projective cover against the background of climate warming reach a maximum in shrubs (Betula spp., Salix spp.); then follow Siberian larch (Larix sibirica Ledeb.), Siberian stone pine (Pinus sibirica Du Tour), and Siberian fir (Abies sibirica Ledeb). The abundance of P. sibirica undergrowth in the mountain forest–tundra ecotone has increased, which is due to a rise in May–August air temperatures (r = 0.97). In zones with sufficient moisture supply (high mountains), warming stimulates radial growth of trees and shrubs and promotes their expansion to the mountain forest–tundra.

Effects of Robinia pseudoacacia on the undergrowth of herbaceous plants and soil properties in the Loess Plateau of China

Abstract: The introduction of Robinia pseudoacacia (RP) has some effects on undergrowth herbaceous plants (UH), soil properties and their relationships, which may be related to the vegetation zone. However, few studies have tested effects of RP on UH and soil over a large-scale area of the Loess Plateau. The study area consisted of three vegetation zones (the steppe, forest-steppe and forest zone). Two canopy plant types were selected: RP stands and adjacent native vegetation. We measured five leaf functional traits: leaf carbon content (LC), leaf nitrogen content (LN), leaf phosphorus content (LP), specific leaf area (SLA) and leaf tissue density (LTD). The functional diversity, species diversity and community-weighted mean (CWM) traits were calculated. (i) CWM.LN, CWM.LP and CWM.SLA increased significantly, whereas CWM.LC and CWM.LTD decreased significantly in the three vegetation zones, compared with the native communities. (ii) Species diversity, functional diversity and community biomass decreased in the steppe zone, increased in the forest zone, and did not differ significantly in the forest-steppe zone. (iii) We found only soil organic carbon (P < 0.05) and soil total nitrogen (P < 0.05) in the forest zone decreased significantly compared with the native plots. (iv) The relationship between UH and soil properties was affected by RP and the vegetation zone. Overall, the effect of RP on UH and soil properties was associated with the vegetation zone. This result is of great significance to the planning of restoration and reconstruction of artificial forests in the Loess Plateau.

The Effect of Informal Tourist Trails on the Abiotic Conditions and Floristic Composition of Deciduous Forest Undergrowth in an Urban Area

Abstract: The study aimed to assess the effect of informal tourist trails on the abiotic conditions and floristic composition of deciduous forest undergrowth in an urban area The study was carried out in the Wolski Forest in Krakow (Poland) in 2020 using a total of 400 plots (1 m × 1m) situated in close (CL) and further (FU) vicinity of informal (<50 cm in width) and formal (≥150 cm in width) tourist trails in the forest interior and forest edge sitesAgreater content of N-NH4, P, and K occurred in the forest interior sites, while greater light intensity, species number, total plant cover, and stem height were found in the forest edge sites Greater light intensity and a higher percentage of total and damaged plant cover were recorded in CLplots, while a greater height of plants was seen in FUplots The number of species was higher in plots located along informal trails than in plots along formal trails The dominance of therophytes and autochorous species along informal trails in the forest interior sites might be a result of successful diaspore dispersal by people walking, while the substantial share of zoochorous species along formal trails suggests their dissemination by dogs accompanying visitors The dominance of forest and ruderal taxa in the forest interior sites suggests unfavourable conditions for the germination of meadow and grassland species The higher cover-abundance of alien plants in CL plots along informal trails and FU plots along formal traits suggests that alien plants growing near the formal trails are more exposed to mechanical damage

Смена пород в неморальных ельниках ЦентральноЛесного заповедника

Abstract: The paper discusses changes in forest-forming species in the nemoral spruce forests of the Central Forest Reserve (Tver Region, the Russian Federation). A comparison is made of the characterization of vegetation in the reserve spruce forests, carried out during the first survey of the reserve by Ya. Ya. Alekseev in 1931 (Alekseev, 1935) with the descriptions of vegetation made by the author from 2011 to 2019. It is shown that the coverage of nemoral herbs in the spruce forests of the reserve has increased over the past 90 years. In addition, three types of broadleaf trees (Tilia cordata Mill., Acer platanoides L. and Ulmus scabra Mill.) have greatly increased their abundance in the stand, most notably the linden. In recent decades, the decay of nemoral spruce forests has been taking place in the Central Forest Reserve. The birch-aspenspruce stand is not replenished with spruce renewal but is replaced by linden-maple forests. The vitality of spruce undergrowth is deteriorating. After the decay of a spruce forest, a change of the tree dominants occurs on 74% of the trial plots and the stand continues with a spruce forest on 26%. The largest part of the reserve's nemoral spruce forests arose after major disturbances 100–150 years ago (on the site of burned-out areas, hurricane windblows and cuttings). Old nemoral spruce forests were formed during the period when severe frosts prevented linden and maple from entering the stand. Currently, the coincidence of climate warming with the aging of the spruce stand and the removal of anthropogenic influence contributed to the release of maple and linden from the undergrowth into the stand and change to a spruce-deciduous forest. Under the prevailing climatic conditions, a return to the spruce forest is possible in the event of a burning out or when the climate becomes cold. The nemoral spruce forest is an ecotone type and, depending on conditions, becomes a spruce or broad-leaved forest.

Above-ground carbon storage in Pinus pumila along an alpine altitude in Khingan Mountains, Inner Mongolia of China

Abstract: The carbon (C) cycle in alpine ecosystems is sensitive to climate change, but information about the C storage in its undergrowth is scarce. In October 2017, a total of 6231 Pinus pumila (Pall.) Regel trees were investigated for above-ground growth and density in 60 sub-plots (10×10 m) from 12 stands (50 × 50 m) along the altitudinal gradient (800-1500 m a.s.l.) in Great Khingan Mountains, Inner Mongolia, Northeast China. Sites were characterized by different crown densities (CDs) from 20% to 90%. Height and root-collar diameter (RCD) were higher in stands with CDs of 40-70% than CDs of 20-30%. Stem density (SD) and crown area (CA) had a positive correlation with altitude and CD. Equations from local shrub models were used to adapt the allometric growth models for estimation. There were variations in estimated above-ground C density depending on the model and the involvement of the canopy area. Above-ground C storage in P. pumila individuals ranged from 0.05-2.46 kg tree-1, which corresponds to C storage density ranged from 0.17-37-ton ha-1. The C density in P. pumila increased with crown density instead of stem density along increasing altitudinal gradients and increasing RCD. Hence, the crown density and diameter of a P. pumila plant can be used to predict the above-ground C density of its natural population.

Early effects of crop tree management on undergrowth plant diversity and soil physicochemical properties in a Pinus massoniana plantation.

Abstract: Background Soil and understory vegetation are vital components of forest ecosystems. Identifying the interaction of plantation management to vegetation and soil is crucial for developing sustainable plantation ecosystem management strategies. As one of the main measures of close-to-nature management of forest plantation, few studies have paid attention to the effect of crop tree management on the soil properties and understory vegetation. Methods A 36-year-old Pinus massoniana plantation in Huaying city, Sichuan Province was taken as the research object to analyse the changes in undergrowth plant diversity and soil physicochemical properties under three different crop tree densities (100, 150, and 200 N/ha). Results Our results showed that the contents of available phosphorus, organic matter and hydrolysable nitrogen in the topsoil increased significantly after crop tree management, while content of available potassium decreased. The composition of shrub and herb layer was richer, and the dominant species were obviously replaced after crop tree management. The Shannon-Wiener index and Richness index of shrub layer, and the diversity of herb layer increased significantly after crop tree management. Herb layer diversity indexes and Richness index of shrub layer were closely related to soil organic matter, available phosphorus, hydrolysable nitrogen, available potassium, soil moisture and bulk density. As the main limiting factors for plant growth, nitrogen, phosphorus and potassium were closely related to plant diversity and to the distribution of the dominant species. At the initial stage of crop tree management, each treatment significantly improved the soil physicochemical properties and plant diversity of Pinus massoniana plantation, and the comprehensive evaluation was 200 N/ha >100 N/ha >150 N/ha >CK. Compared with other treatments, 200 N/ha had the best effect on improving the undergrowth environment of the Pinus massoniana plantation in the initial stage of crop tree management.

Investigation of sentinel-1 time series for sensitivity to fern vegetation in an european temperate forest

Abstract: . In this study, a dense Copernicus Sentinel-1 time series is analyzed to gain a better understanding of the influence of undergrowth vegetation, in particular of eagle fern (Pteridium aquilinum), on the C-band SAR signal in a temperate forest in the Free State of Thuringia, Germany. Even if signals from the ground below the canopy may not be expected at C-band, previous studies showed seasonal fluctuations of the backscatter for temperate forests without canopy closure, notably for evergreen coniferous stands. Many factors can be responsible for these observed fluctuations, but in this study, we analyze one possible factor: the presence of undergrowth vegetation, in particular, of fern. Especially, the Sentinel-1 backscatter signal is analyzed for different acquisition configurations regarding its temporal and its spatial stability at different growth stages. This time series study shows that a difference of backscattered signal of up to 0.7 dB exists between forest patches with a dense fern density in the understory and the ones with low undergrowth vegetation. This signal difference depends on the season and is remarkably strong comparing winter (no fern undergrowth) with summer (major fern undergrowth).

The characteristics of seedling regeneration and its influencing factors of Pinus tabuliformis under different wildfire severity of Liaoheyuan Nature Reserve

Abstract: Purpose This paper studies the characteristics of the seedling regeneration, stand structures, undergrowth biomasses, litter amounts and soil water contents of planted forests of Pinus tabuliformis in the Liaoheyuan Nature Reserve after a fire disturbance in 2014 and analyzes the significant factors affecting seedling regeneration to offer a scientific basis for the ecological restoration of vegetation in burned areas. Methods Plots of forest stands that experienced different fire severities (high severity, moderate severity, low severity) and control sample plots were used to study the significance of differences in seedling regeneration, stand structure, undergrowth biomass, litter amount and soil water content characteristics among stands under the effects of different fire severities by using single element variance analysis. The major factors affecting seedling regeneration characteristics were also analyzed here by using correlation and principal component analyses. Results (1) There was no significant difference in the density and growth characteristics (base diameter, plant height and crown diameter) of regenerated seedlings of Pinus tabuliformis under the different fire severities (P ​> ​0.05), and the spatial distribution of regenerated seedlings fit the aggregated distribution pattern. (2) There was no significant difference in diameter at breast height (DBH), plant height or crown diameter of Pinus tabuliformis under different fire severities (P ​> ​0.05), but there were highly significant differences in scorch height, biomass of undergrowth woody plants, biomass of undergrowth herbs, undecomposed litter amount, semidecomposed litter amount and soil water content under different the fire severities (P ​ Conclusion In the 5th year after a fire disturbance, the seedling regeneration of Pinus tabuliformis in a burned area was influenced by factors such as the stand structure, undergrowth plants, litter and soil. Low- and moderate-severity fires promote the natural regeneration of stands and are conducive to the stable balance of ecosystems.

Undergrowth phytodiversity index in exotic and indigenous tree plots in Hoteya forest range of Sakhipur upazila under Tangail forest division, Bangladesh

Abstract: This study was undertaken to know the species diversity of the monoculture plantations of exotic species Acacia auriculiformis and Eucalyptus camadulensis compared to indigenous species Shorea robusta and Mangifera indica. There are 12 sample plots (size 36x36 m) were selected from the study area following the purposive random sampling. A total of 720 quadrats (12 plots x 10 quadrats x 6 seasons) were placed in the sample plots to collect the undergrowth vegetation data over two years of 2010-11 following summer, monsoon and winter season. The average value of Shannon-Wiener diversity index was 2.65±0.16 and 3.28±0.13 that of Simpson’s diversity index was 0.87±0.02 and 0.93±0.01 and that of Margalef’s diversity index was 7.34±0.77 and 10.43±0.52 collectively in all exotic and indigenous plots, respectively. This scenario depicts that the extent of species diversity was higher in indigenous tree species plots than in exotic tree plots and the flora of the study area was highly diversified. The Shorea plots were richer in species diversity out of the four species categories of sampling plots. The index values of three diversity indices were significantly different for the exotic and indigenous tree plots, excluding Eucalyptus and Mangifera species plots, which mean the undergrowth species diversity of Eucalyptus and Mangifera species plots, were not significantly different. Adequate awareness building programs need to conduct among the local community and Bangladesh Forest Department to understand environmental degradation, the importance of conservation management of indigenous ‘Sal’ forest and significance of plant diversity in the village forest for future generations.

Suppressed Undergrowth of Siberian Spruce (Picea obovata Ledeb.) in Early Ontogeny: One-Way Ticket or Survival Strategy?

Abstract: The study examined the growth characteristics of the Siberian spruce (Picea obovata Ledeb.) under the canopy of coniferous forests in early ontogeny. We revealed that spruce undergrowth in adverse conditions is suppressed, is slow to grow and has xylorhizomes. The result is a significant difference in height, age and stage of ontogeny that affects the forest’s growth dynamics. The formation of xylorhizomes changes the relative dimensions of the above-ground part and the plant’s absolute height from 42 to 75%, depending on age. We identified two periods of growth intensity (slow and stable) and the critical age for spruce undergrowth to move from one stage of ontogeny to the next. If it does not make the transition, it will die. There are two strategies for developing spruce undergrowth: a “direct” path during rapid growth and a “waiting” path when the plants are suppressed. Such growth pathways in the pre-generative stage of the Siberian spruce’s ontogeny allow the undergrowth, even in a suppressed state, to survive in an adverse environment under the forest canopy.

Estimating Per Capita Land Use/Land Cover Change (LULCC) in Makurdi, Northcentral Nigeria

Abstract: The study estimated annual and temporal variation in per capita L and U se/ L and C over C hange (LULCC) in Makurdi, Northcentral Nigeria A total of four Landsat TM/ETM+ images were acquired in April of 1991, 1996, 2001 and 2006 for the study A total of five LULC types namely water, forest, undergrowth/wetland, cultivated land and built-up land were derived from the Landsat images using supervised classification method The per capita LULCC was derived by dividing the areas of LULC types by the actual population data The result showed that built-up land recorded the highest long-term gain in area by 179km 2 (130%), with an increment of 87% per anum, and undergrowth/wetland lost 119km 2 (32%) in area with a decrease of 21% per annum from 1991 to 2006 The per capita LULCC of built-up land has increased from 575m 2 /person (1991) to 1059m 2 /person (2006), representing an increment of 481m 2 /person (83%) The undergrowth/wetland recorded the highest decrease in per capita LULCC from 1542m 2 /person (1991) to 836m 2 /person (2006), representing a decline by 706m 2 /person (46%) The study concludes that undergrowth/wetland is the most vulnerable LULC type due to urbanisation, and sustainable urban planning should be practised to conserve the natural cover materials in the study area

Allometric Equations to Estimate the Aboveground Biomass of Seedling and Sapling Plants in 10 and 20 Years Old of Secondary Forests in Sarawak, Malaysia

Abstract: The seedlings and saplings plant stage determines the successional stages in the secondary forest establishment process. The estimation on aboveground biomass (AGB) of seedling and sapling plants is needed to describe undergrowth's contribution in the secondary forest. This study's objective was to develop allometric equations for accurate estimation of AGB for seedlings-saplings in 10 and 20 years old of secondary forests. The study was carried out at sites with two stages of the fallow period: lands with a fallow period of 10 and 20 years, respectively, in Sarawak, East Malaysia. The AGB data of all selected seedlings and saplings with the different species within 100 sample quadrates were used to develop allometric equations for seedlings and saplings in each study site. This study developed allometric equations to estimate AGB of seedlings-saplings (diameter at the ground surface of < 5 cm), particularly in 10 and 20 years of fallow ages.

Характеристика полезащитных лесных полос и их мелиоративный эффект на подсолнечник в зоне южных карбонатных черноземов

Abstract: The article deals with the issues related to the characteristics of protective forest strips and their impact on the yield of agricultural crops in the Troitsky farm of the Mikhailovsky district of the Volgograd region. Methodology. The characteristics of forest strips are typical. The spatial orientation of protective forest strips, species composition, height, undergrowth, number of rows, distance between rows and seats in a row, density and safety of plantings, width, openwork, design of forest strips are considered. Forest strips with sunflower biocenosis represent the ecosystem. The inter-lane space was taken into account from the forest strip at a distance of: 5; 10; 15; 25 and 35 heights (H). The control was the middle of the inter-lane cell. The bio-productivity of sunflower was determined by the phases of development: leaf area, assimilating surface, photosynthetic potential. For the analytical expression of the spatial dynamics of the photosynthetic potential an exponential dependence was used. Oil content at the end of the growing season was measured on the basis of interstate standards GOST 10857-64, GOST 13586.3 and GOST 10853-88 using a digital laboratory moisture-oil meter VMTSL-12M. The aim of the research was to identify the reclamation effect of the influence of protective forest strips on the bioproductivity of sunflower with minimal tillage (or no-till technology). Conclusion. Features of the bio-productivity of sunflower hybrid in the inter-lane space are expressed in the patterns of development of assimilating the surface on logistics and photosynthetic potential is exponential. The yield of the hybrid varies depending on the weather conditions, the presence of nutrients in the soil and does not differ fundamentally by year. Consequently, the cultivation of the LG-5456 hybrid in humid years in the zone of influence of forest strips using the no-till technology showed good results. The obtained data prove that forest-reclamation plantings in agricultural landscapes are one of the most durable and environmentally friendly factors for increasing the productivity of agricultural land.

Influencing Factors of Undergrowth Economic Growth From the Perspective of Linear Analysis

Abstract: In order to build a comprehensive and systematic management mechanism of forest management, make full use of limited forest land resources, and achieve the goal of sustainable development, this paper summarizes the influencing factors of current undergrowth economic development. Therefore, this paper proposes a linear analysis of the factors affecting the undergrowth economic growth. According to the current situation of economic development under forest, the model structure is designed in the view of linear analysis. In addition, the basic principles involved in the linear analysis are analyzed, and the multiple linear regression model is established to analyze the influencing factors of undergrowth economic growth. The results show that the method is effective and provides technical support for the rapid development of undergrowth economy.

Effects of Adjacent Land Use Types on the Composition of Vascular Flora in Urban Forest Ecotones in the Southern Poland

Abstract: The purpose of the research was the recognition of edge effects regarding similarities and differences of vascular flora in undergrowth layers in the urban forest ecotones. Four types of urban forest neighborhoods were analyzed: ecotones adjacent to the manor park, the agriculture field, housing estates and the road. The plant compositions in the forest ecotones were compared with the plant compositions in the urban forest interior and the forest nature reserve. The phytosociological type of studied forests was a subcontinental oak-hornbeam one (Tilio-Carpinetum). Diagnostic plant species (e.g., characteristic) for forests from the non-diagnostic ones were identified. Forest consistent plant species dominated in the ecotone adjacent to the manor park and in the interior of urban forests too, but the best conditions for these plants were inside the forest nature reserve, where native consistent forest plants showed the highest dominance when comparing all studied areas. A higher anthropogenic pressure from the adjacent areas results in supporting the growth of inconsistent plant species in the forests, and these plants are mostly represented by plants belonging to grass and synanthropic communities. Another conclusion drawn from our research is that the protected forest, represented by a nature reserve in the city, provides better “shelter” for native forest plants than the urban forest without any protection. Ultimately, a permanent challenge is to achieve and maintain the balance between nature and the impact of anthropogenic activities on urban forests in the city. The high quality of green areas, biodiversity, including forests, implicates possibilities of sustainable development in cities. The research results will be useful for local urban planners and ecologists during their work on strategies of city development, including shaping of green infrastructure.

Secondary Serpentine Forests of Poland as a Refuge for Vascular Flora

Abstract: The aim of present study was to determine the role of secondary, serpentine forests in Poland in the protection of rare vascular plant species. On the basis of 95 phytosociological releves collected between 2009 and 2020, we identified the main types of serpentine forest communities and assessed their diversity indices. Ordination methods were used to determine the relationship between the degree of transformation of forest communities (reflected by the occurrence of alien and nitrophilic species) and the presence of endangered species in their undergrowth including the environmental background. We distinguished four types of communities: thermophilic and mesophilic pine plantations (both secondary in origin) as well as thermophilous oak forest and acidophilous oak–hornbeam forest (semi-natural and close to natural in character, respectively). Rare and endangered species were unevenly distributed and concentrated in oak forest (16 species) and thermophilic pine plantation (nine species). The endangered species mainly preferred sites at higher altitudes and with higher slope inclination, light availability, and soil reaction. We did not confirm that the presence of alien or nitrophilic species negatively influenced the ability of studied forests to preserve rare plants. As secondary forests can still harbor endangered species, they should fulfil complementary functions in the nature protection system.

Comparative analysis of the competition of stands of different species composition in relation to the Siberian stone pine undergrowth

Abstract: Under the canopy of the parent native berry-green-moss Siberian stone pine forest and derivatives berry-green-moss pine and birch forests on the Urals, using the previously proposed complex of light, root, and integral competition indices of the stand, a comparative analysis of the parameters of the Siberian stone pine undergrowth is carried out. Under the canopy of Siberian stone pine forest two main determining factors have a negative complex effect on the growth of the Siberian stone pine undergrowth: the light competition of the stand (the level of photosynthetically active radiation interception by its canopy) and, almost equal to it, the root competition for soil nutrition. Under the pine forest canopy with the combined negative effect of factors of light and root competition of the stand on the development of Siberian stone pine undergrowth, light competition is decisive. The effect of the root competition is less than almost two times. Under the birch forest canopy the main factor determining the development of Siberian stone pine undergrowth is the light competition of the stand. The connection with the root competition of stand is not expressed.

Mid-Term Effects of Forest Thinning on N Mineralization in a Semi-Arid Aleppo Pine Forest

Abstract: In order to assess the sustainability of silvicultural treatments in semiarid forests, it is necessary to know how they affect the nutrient dynamics in the forest. The objective of this paper is to study the effects of silvicultural treatments on the net N mineralization and the available mineral N content in the soil after 13 years following forest clearings. The treatments were carried out following a randomized block design, with four treatments and two blocks. The distance between the two blocks was less than 3 km; they were located in Chelva (CH) and Tuejar (TU) in Valencia, Spain. Within each block, four experimental clearing treatments were carried out in 1998: T0 control; and T60, T75 and T100 where 60%, 75% and 100 of basal area was eliminated, respectively. Nitrogen dynamics were measured using the resin tube technique, with disturbed samples due to the high stoniness of the plots. Thirteen years after the experimental clearings, T100, T75 and T60 treatments showed a twofold increase in the net mineralization and nitrification rates with respect to T0 in both blocks (TU and CH). Within the plots, the highest mineralization was found in sites with no plant cover followed by those covered by undergrowth. These results can be explained in terms of the different litterfall qualities, which in turn are the result of the proportion of material originating from Pinus halepensis Mill. vs. more decomposable undergrowth residues.

Fitofisionomia da cobertura vegetal na ilha de Colares no Nordeste Paraense

Abstract: The effects resulting from the disorderly occupation and forest fires for the implantation of pasture and the increase of urban centers are the major problems in the 21st century, which have triggered major changes in the forest composition in the municipalities of Para. As a result of the current situation, geoprocessing becomes an aid tool in the monitoring and management of environmental change processes. Associated with the Normalized Difference Vegetation Index (NDVI) technique, which enables the study of the dynamics of vegetation cover and the mechanisms correlated to land use and occupation. Thus, the objective is to analyze the vegetation cover with emphasis on the characterization of the fragments of arboreal vegetation present in the landscapes of Ilha de Colares. Using Landsat 8 ETM+ satellite image, OLI scene sensor - 223/061 and 223/061 in the period of 07/16/2017 and 06/15/2018, spectral sensor OLI (Operation Land Imager) and thermal TIRS (ThermalInfrared Sensor) made available by Science for Changing world – USGS. The generated product was divided into 6 reflectance intervals in each of the years analyzed. The results point to increased anthropogenic action in the region under study and the appearance of undergrowth in the interior areas of the island's coastal plain and fragmentation of dense forests along the region.

Influence of Roe Deer on the State of Undergrowth in Oak Groves at the Karadag Nature Reserve

Abstract: This paper presents data on the state of stands and undergrowth of the main forest-forming species at the Karadag Nature Reserve in oak forests of downy oak (Quercus pubescens) and sessile oak (Q. petraea) under the conditions of an excessive density of the European roe deer (Capreolus capreolus). By 2016, the exponential growth in the number of roe deer in the reserve, which has been observed since its establishment in 1979, led to an increase in its number to 750 individuals and density of up to 437 individuals per 1000 ha, which is 10 times higher than the norm. At the same time, the level of damaged undergrowth increased from 7.6 to 88.9% in sessile oak and from 8.4 to 83.7% in downy oak. This has resulted in a decrease to an absolute minimum in the numbers of the medium and the complete absence of large undergrowth in both sessile oak and downy oak. The alignment of tree species in abundance (estimated by the Berger–Parker index) is 1.2 for sessile oak stands and 1.18 for downy oak stands; the undergrowth is 3 and 1.6, respectively. At the Primorskoe Forestry located next to the reserve, which exhibits a relatively satisfactory density of roe deer (37 individuals per 1000 ha), damage to the undergrowth of the main species was 5.5% in sessile oak groves and 7.2% in downy oak groves. In the Primorskoe Forestry oak forests, alignment of tree species in abundance is 1.25 for sessile oak and 1.54 for downy oak and 2.15 and 2.11 for their undergrowth, respectively. Based on cumulative data, it is concluded that even providing the conditions of a super-high density of ungulates, oak forests of the Karadag Reserve retain the ability to regenerate through an increase in the density of small undergrowth (sessile oak groves) and alignment of the undergrowth species (downy oak groves). The role of the overabundance of roe deer in the reserve is negative in relation to the reproduction of the main species and positive in regards to biodiversity in terms of the alignment of tree species of the undergrowth in abundance.