Natural Regeneration Of Tree Species Research Articles

Features of natural renewal in pine-linden and larch-linden forest stands in Moscow

Problems of natural renewal of tree species (pine-linden and larch-linden stands) were studied in the territory of Forest experimental station, Moscow Timiryazev Agricultural Academy. Natural regeneration of tree species is one of the most urgent problems of forestry and forest park management in urban areas. Reforestation refers to complex natural processes that affect all components of biogeocenoses. The purpose of the research was to study natural regeneration in mixed stands in Moscow. Methods and results of field surveys of forest stands in permanent trial plots were described. The forest stands of permanent trial plots are mature and overmature, therefore at present there is a loss of large-sized pine and larch trees. Due to greater durability, larch falls off more slowly compared to pine. Further growth of pine-linden and larch-linden plantations depends on quantity and quality of undergrowth, its viability and growing conditions. In Forest experimental station, natural renewal prevails, represented mainly by the following species: maple and linden. Saplings of pine, larch, oak, and birch appear on some permanent test plots, but soon die due to unfavorable conditions. Oak undergrowth is also unreliable due to powdery mildew infection. The greatest loss of growth occurs in unfavorable growing conditions due to increased recreational loads.

The natural regeneration characteristics in oak forests following different methods of clearcutting

An important task for Ukrainian foresters is to adapt forests to climate change and ensure sustainable forest management. One key measure for achieving this goal is the natural regeneration of tree species, which contributes to the biological resilience of forest stands. The purpose of this study is to assess the impact of different methods of main use fellings on the natural regeneration process of tree species in oak forests. The study was conducted within the territory of the Stradch Forestry Educational and Production Complex of the Ukrainian National Forestry University. Data on the quantity and height of oak seedlings and saplings, and other tree species, were collected through observation after various methods of main use fellings were applied in oak forests. An analytical method was applied to detect patterns and differences in quantitative and qualitative indicators of young trees of different species in sample plots. Statistical data analysis was employed to establish relationships and draw conclusions based on numerical data. Different success rates of natural regeneration of tree species were identified on plots subjected to various methods of main use fellings. Positive dynamics in the quantity of seedlings and saplings were observed due to first intervention of the uniform shelterwood felling, ranging from unsatisfactory to good levels. It is recognised that the distribution of seedlings and saplings of all tree species was uneven across the area. Hornbeam has the highest frequency of occurrence – 75.6%. Tree species like Scots pine, European birch, and goat willow exhibited occurrence frequencies ranging from 30.8% to 39.7%. In general, in all the studied areas, the undergrowth of tree species was dominated by a small fraction up to 20 cm of height. To ensure the prevalence of pedunculate oak in naturally formed young stands, silvicultural care for its saplings is necessary on all plots. The obtained results provide a basis for developing scientifically grounded forest management measures aimed at increasing the quantity and quality of valuable tree species’ saplings, particularly pedunculate oak

Structure of the Ground Vegetation and Natural Regeneration of Tree Species in a 12–15-Year-Old Bilberry Pine Forest–Clear-Cut Ecotone Complex in the Middle Taiga Subzone

Structure of the Ground Vegetation and Natural Regeneration of Tree Species in a 12–15-Year-Old Bilberry Pine Forest–Clear-Cut Ecotone Complex in the Middle Taiga Subzone

Stable isotope composition in tree rings of Fagus sylvatica L. saplings reflects environmental variation induced by silviculture and microsite factors

Natural regeneration of tree species is sensitive to silvicultural interventions. This study aimed to investigate the effects of different cutting intensities and local topographic and soil conditions on the composition of stable carbon (δ13C) and oxygen (δ18O) isotopes in wood of young beech (Fagus sylvatica L.) trees. Beech saplings in the regeneration layer were sampled in summer 2018 at three study sites in Dinaric fir-beech forests in the karst area of Slovenia. Three different cutting intensities were performed in 2012: i) no cutting (control), ii) 50% cutting of the stand’s growing stock creating thinned stands, and iii) 100% cutting of the stand’s growing stock creating 0.4 ha canopy gaps. We show that δ13C increased along the gradient of cutting intensity. On average, δ13C values in the tree rings were ∼ 2‰ increased in trees from canopy gaps than from closed control stands. Furthermore, δ13C was higher on south-facing slopes characterized by higher air temperatures and lower relative humidity compared to north-facing slopes of karst sinkholes. Additionally, the results suggest a dependence of δ18O on interannual and cross-site climatic variations, particularly in the case of summer precipitation amount. δ18O also responded to soil depth, with beech individuals exhibiting lower values on deeper soils, presumably characterized by higher soil water availability compared to shallow soils. The results are discussed in the context of future climate change, as many beech-dominated forests on karst terrain in the Dinaric Mountains are particularly affected by climate warming and drying due to prolonged and reoccurring summer droughts, intensified large-scale disturbances, and often shallow soils with low water storage capacity.

SURVIVAL AND NATURAL REGENERATION OF FOREST ESSENCES CULTIVATED IN ALTERED AREAS THIRTY-FIVE YEARS AFTER PLANTING

The evaluation of the survival and natural regeneration of tree species in a 35-year-old plantation was carried out to identify the species established in the area, aiming at their recommendation in forest restoration plantations in the State of Acre. In the 1980s, 138 forest species were planted in two experimental units (EU), of 1.38 ha each, in the Zoobotanical Park (ZP) of the Federal University of Acre, Rio Branco campus. The main activities carried out in the area, prior to planting, were agriculture and cattle raising. Survival status was measured through a census of all individuals planted at the time, who were still alive. In addition, all regenerating individuals from planted species were surveyed in the effective planting area of the experimental units. At the time of evaluation, living individuals of 41 and 46 species were found in experimental units 1 (EU-1) and 2 (EU-2), respectively. The species Syagrus sancona, Talisia esculenta, Acacia polyphylla, Couepia bracteosa, Mangifera indica, Syzygium cumini and Copaifera multijuga showed survival rates above 90% in at least one of the experimental units. Only Syagrus sancona and Handroanthus serratifolius presented high survival rates in both experimental. Regenerating individuals of the species Aspidosperma vargasii, Couepia bracteosa, Euterpe precatoria, Handroanthus serratifolius, Oenocarpus mapora, Onychopetalum periquino and Stryphnodendron pulcherrimum were found in the two EU.

Естественное возобновление в смешанных разновозрастных древостоях на урбанизированных территориях Москвы

The effectiveness of forests therapeutic impact is based on its species’ and age structure, silvicultural features, biological productivity, regenerative ability, forest management intensity and its methods. The processes of natural regeneration of a forest stand and its growth are the main factors of the forest’s ecosystem proper functioning and a disruption in these processes can lead to a transformation of the whole biocenosis, a change of a typological community. Technogenic pollution is a huge stress factor for trees, and its impact is especially evident in regions with a high concentration of industrial facilities, namely, in Moscow city. One of the most serious consequences of technogenic pollution is the deterioration of long-established forests, which subsequently may reduce its ability to adapt to ever-changing environmental conditions and its protective functions. The article discusses issues regarding the natural regeneration of forests on urbanized territories of Moscow on the example of the Forest experimental station of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. The natural regeneration of tree species is one of the most relevant issues of forest and park management. The aim of this project is to estimate natural regeneration in mixed forest stands of urbanized areas, to provide recommendations on the organization of forest regeneration measures in urban environments. The article provides methods and results of field research and recommendations on reforestation measures under these conditions. The research of the cenobiotic connections and the undergrowth of different species with key elements of grass cover in its habitat, will allow a more positive dynamics in the use of natural resources, which will contribute to preservation and restoration of forests.

Formation of phytocenoses on lands disturbed by oil extraction in the Udmurt Republic

The Udmurt Republic is a region in which the oil extraction industry occupies a leading place in the economy along with metallurgy and mechanical engineering. Oil exploration work has been carried out here since the 40s of the XX century. Today, there are over 120 oil fields in the territory of Udmurtia. Every year, geological exploration of the subsoil contributes to the identification of new territories in which work on hydrocarbon raw materials’ extraction is planned in the future. A significant part of these territories is located on the lands of the forest fund. To characterize the dynamics of environmental conditions and predict measures for the rational formation of post-technogenic territories, it is important to study the overgrowing processes of disturbed lands. The study of technogenic landscapes makes it possible to assess the disturbance degree of the vegetation, living ground cover. The article shows the features of phytocenoses formation, their species diversity in the conditions of oil production on the territory of the Udmurt Republic. The growth and development of living ground cover, natural regeneration of tree species depending on the age and degree of pollution have been investigated. It was found that with an increase in the technogenesis age, an increase in the proportion of forest species in phytocenoses takes place. Therefore, when forecasting for a longer period, one can expect the formation of plant communities mainly from forest tree and shrub species.

Tree species composition and height structure of undergrowth in fresh hornbeam-oak-pine forest on relatively rich soils of the Ukrainian Roztochia

The fresh hornbeam-oak-pine forest on relatively rich soils of the Ukrainian Roztochia is characterized by a good natural regeneration of tree species, both under the forest canopy after the first irregular shelterwood cutting, and on two clear cut areas. After the first irregular shelterwood cutting, the total amount of self-seeding and undergrowth changes from unsatisfactory (10.480 pieces/ha) at the beginning of the 2020 vegetation season to good (41.528 pieces/ha) at the end of the 2020 growing season. A year later, its number has not changed and 42.693 individuals/ha were counted. However, the share of pedunculate oak in the total number of undergrowth here is only 1.7%. Natural regeneration of all tree species under the forest canopy is characterized by an uneven distribution in the area. Hornbeam has the highest incidence rate - 75.6%. Species such as Scots pine, hanging birch and goat willow have a frequency of 30.8 to 39.7%. Other tree species are much less common, including pedunculate oak (abundance from 1.3% to 12.8%). On clear cut areas the total amount of self-seeding and undergrowth varies from 175.6-275.3 units/ha at the beginning of the vegetation period of 2020 to 299.4 thousand pieces/ha at the end of that vegetation period, and a year later, in autumn 2021 it reached 461.2 thousand pieces/ha. Hornbeam also had the highest abundance rate - 97.3-98.1%, followed by pedunculate oak (43.5-77.3%), birch (42.6-52.7%) and pine (29.6-34.0%). Other tree species, such as lime, willow, sycamore, beech, elm, aspen, and others, had a frequency of 0.7 to 20%. In general, in all the studied areas, the composition of self-seeding and undergrowth was dominated by a small fraction up to 20 cm in height. To ensure the advantage of pedunculate oak in the naturally formed young stands in all areas it is necessary to carry out silvicultural treatments such as cleaning or precommercial thinning.

Natural Advance Regeneration of Native Tree Species in Pinus radiata Plantations of South-Central Chile Suggests Potential for a Passive Restoration Approach

Restoration of natural forests previously replaced by plantations is a widespread challenge for forestry in Chile and elsewhere. However, there is little documented evidence for successful restoration, either through active or passive approaches. In this study, we aimed at (1) determining the potential for passive restoration in first-rotation Pinus radiata plantations through natural regeneration of native tree species and (2) identifying drivers of this advance regeneration. Across different regions in south-central Chile, we established nearly 260 plots to assess regeneration and environmental conditions along 26 transects running from plantations into adjacent natural forests. The regeneration was exclusively composed by native species, except for 7 individuals of P. radiata. Mean density and diversity of seedlings were significantly higher in natural forests than in plantations, but this was not the case for sapling density, and no differences in sapling diversity were supported. Additionally, significant differences in regeneration composition between plantations and natural forests were found only at two of the eight study sites. Compared to climatic and soil chemical variables, which varied mostly at regional scales, local environmental conditions showed little influence on regeneration, possibly due to the structural homogeneity of plantations. Yet, the significantly higher basal area, litter thickness and gap fraction of plantations compared to natural forests suggest that these factors may explain differences at the seedling stage. Our study indicates that the use of appropriate harvesting methods that maintain advance regeneration may facilitate the transition from plantations to native forests through passive restoration. The use this approach should be further investigated through analyzing regeneration’s response to different forms of plantation harvesting.

Effects of Wildfire and the Presence of the Invasive Paulownia tomentosa on the Regeneration of Native Tree Species in North-Central Appalachia

A wildfire occurred in Shawnee State Forest located in southern Ohio that consumed 1215 hectares. Based on earlier forest inventories it was known that paulownia (Paulownia tomentosa), a non-native invasive tree species, occurred in the forest. The objective of this study was to determine if paulownia heavily colonized areas two years after the fire where the burn occurred, and if its presence had a negative impact on the regeneration (<137 cm height) of native species—red and white oaks (Quercus sp.), red maple (Acer rubrum), and yellow-poplar (Liriodendron tulipifera). Two years after the fire, paulownia had invaded the burned areas but not at significantly higher densities than occurred in the unburned areas. Fire significantly reduced the number of regenerating stems of white oak and red maple two years after the fire, whereas the number of regenerating stems of red oak increased slightly and that of yellow-poplar increased significantly. In areas where paulownia occurred that experienced wildfire, all species studied displayed a reduction in the number of regenerating stems compared to paulownia’s absence in the burn areas. Where paulownia occurred in areas not affected by the wildfire, all the native species studied displayed a reduction in the number of regenerating stems. The average heights of red oak, white oak, and red maple were significantly taller when growing in areas affected by the wildfire due to a more open canopy. However, there was no significant change in the average heights of yellow-poplar. The presence of paulownia in both the burned and unburned areas reduced the number of regenerating stems of the native species studied.

Woody Species Composition, Vegetation Structure, and Regeneration Status of Majang Forest Biosphere Reserves in Southwestern Ethiopia

The aim of this study was to analyse the species composition, structures, and regeneration of woody plant species and the impacts of site factors on the natural regeneration of tree species in four study sites of MFBR. The vegetation data were collected systematically in 140 plots with the size of 400 m2 for trees; 25 m2 for seedlings, saplings, shrubs, and lianas; and 1 m2 for herbs. Individual tree and shrub DBH ≥ 5 cm were measured and counted. The diameter at breast height (DBH), frequency, basal area, importance value index (IVI), and density were used for vegetation structure description and regeneration. A total of 158 plant species belonging to 115 genera, 56 families, and 80 species (51%) trees, 26 (16%) shrubs, 19 (12%) herbs, and 33 (21%) lianas were identified and recorded. The most dominant families were Euphorbiaceae, Rubiaceae, and Moraceae, each represented by 13 species (7.4%), 12 species (6.8%), and 10 species (5.7%), respectively. The tree densities varied from 1232 to 1478 stem ha−1, sapling density 176.8 to 708.7 stem ha−1, and seedling density 534.7 to 1657.5 stem ha−1, with an average basal area of 63.6 m2 in the study sites. Dracaena afromontana was the most frequent woody species in the MFBR occurring in 90% followed by Celtis zenkeri (65%) and Pouteria altissima (62.5%). The regeneration status of all the woody plant species was categorised as “not regenerate” (9.6%), “poor” (30.7%), “fair” (59.5%), and “good” (10.8%) in all sites. The correlation result between natural regeneration and site factors revealed both positive and negative relationships. However, the main threat to the biosphere reserve is illegal logging for different purposes. Therefore, awareness creation on sustainable forest management, utilisation, conservation of priority species, and livelihood diversification to the local community and encouraging community and private woodlot plantation in the transitional zone of biosphere reserves are recommended.

Effects of prescribed grazing by goats on non‐native invasive shrubs and native plant species in a mixed‐hardwood forest

Invasion of non‐native shrubs comprises a serious economic and ecological problem in North American forests. Prescribed grazing by goats may offer an effective alternative to traditional methods of control, but has received little study in forest settings. In a 5‐year field experiment, we varied the stocking of goats and number of grazing periods to determine effects of prescribed grazing on both invasive shrubs and native plant species. Specifically, we examined how varied stocking levels and grazing periods affect: (1) the cover and height of invasive shrub and native woody species (2) the cover and diversity of herbaceous species, and (3) the density of native tree seedlings. Data were analyzed with linear mixed‐effects models. We found that prescribed grazing by goats significantly reduced the cover and height of invasive shrubs, regardless of goat stocking or duration. Generally, the greatest reductions in invasive shrub cover occurred in treatments with two grazing periods, regardless of goat stocking. While we observed mostly neutral or positive effects on the herbaceous layer, all grazing treatments reduced the cover and height of native understory woody species. While changes were not significant, we observed a general decline in the aggregate height of native tree species regeneration. Our results suggest that prescribed grazing by goats provides an effective and environmentally friendly treatment for heavy invasions of non‐native shrubs such as Rosa multiflora, but grazing needs to be followed by focused mechanical or chemical treatments to maintain control while allowing the regeneration of native tree species.

The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

The positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.

Effects of Man-powered Scarification and a Rhizome Cutting Treatment on Natural Regeneration of Tree Species in Dwarf-bamboo Grassland

Effects of Man-powered Scarification and a Rhizome Cutting Treatment on Natural Regeneration of Tree Species in Dwarf-bamboo Grassland

Restoring native forests from Pinus radiata plantations: Effects of different harvesting treatments on the performance of planted seedlings of temperate tree species in central Chile

Extensive areas of native vegetation have been cleared to establish commercial exotic tree plantations in south-central Chile, a region known as a world biodiversity hotspot. Despite increasing societal demands to restore native forests in parts of the landscape, documented experiences for this form of restoration are lacking. We conducted a landscape-replicated experiment to test the influence of different harvesting treatments (clearcut, strip-cutting and unharvested control) on the early establishment of native tree species in 20-year-old Pinus radiata plantations. Group plantings of shade-intolerant (Nothofagus dombeyi; Nothofagus obliqua), semi-tolerant (Nothofagus alpina; Laurelia sempervirens) and shade–tolerant species (Aextoxicon punctatum; Cryptocarya alba) were established across the treatments, and seedling performance and water status were monitored during the first two growing seasons. Mean survival was significantly higher in the strip-cuttings (77%) and control (70%) than in the clearcuts (38%), while mean height and root collar diameter growth were significantly higher in the strip-cuttings (16 cm year−1; 0.2 cm year−1) and clearcuts (16 cm year−1; 0.2 cm year−1) than in the control (5 cm year−1; 0.1 cm year−1). Shade-intolerant and semi-tolerant species showed the highest growth responses to openings. Leaf water potential was significantly higher in seedlings in the strip-cuttings than those in the control and clearcuts, and stomatal conductance was significantly higher in the strip-cuttings and clearcuts than in the control. Higher seedling performances and lower water stress in the strip-cutting treatment suggest that partial canopy removal is a suitable method for artificial regeneration of native tree species with different shade tolerances for native forest restoration from P. radiata plantations.

More widespread alien tree species do not have larger impacts on regeneration of native tree species in a tropical forest reserve.

There is insufficient information regarding the factors affecting the environmental impacts of alien species. In particular, little is known about whether there is any relationship between the invasiveness (establishment and spread) of an introduced species and its per capita impact. We experimentally assessed the relationship between the extent of spread of up to 29 alien plant species and their impact on recruitment of native tree species in Amani Botanical Garden, Tanzania. We also studied the effects of allelochemicals of selected alien on native plant species to assess potential mechanisms of impact. We found no relationship between the extent of spread of an alien tree species and their impact on seed germination, seedling survival, and seedling communities of native trees in their understory, and no indication that allelochemicals consistently explain their effects on recruitment of the studied species. These results suggest that extent of spread cannot be used as a proxy for impact. Hence, managers should continue assessing both the spread and the impact of alien species when prioritizing alien species for management.

Prospect of natural regeneration of tree species in Hazarikhil Wildlife Sanctuary of Chattogram, Bangladesh

Natural regeneration of tree species is the major means of understanding the restoration potentiality of a secondary forest. Natural regeneration of a forest is a tool for measuring the health of the forest ecosystem. Natural regeneration status of tree species in Hazarikhil Wildlife Sanctuary (HWS) in Chittagong North Forest Division, Bangladesh was assessed laying 75 systematic quadrats of 4m×4m in size. A total of 90 regenerating tree species belonging to 34 families was identified from the HWS. Euphorbiaceae family possessed maximum regenerating tree species (14 species) followed by Mimosaceae (7), Lauraceae and Meliaceae (6 species each), and Moraceae (5 species). The overall seedling density was 7,083 per ha where Ficus hispida showed the highest number of seedlings (792 per ha) followed by Quercus sp. (475), Ficus religiosa (408), Lithocarpus elegans (375) and Lepisanthes rubiginosa (367). The number of Ficus hispida seedlings per ha was higher due to high coppicing ability. Lepisanthes rubiginosa attained maximum IVI (27.59) followed by Ficus hispida (21.18) and Quercus oxyodon (13.32). The seedlings of Aegle marmelos, Lithocarpus sp., Flacourtia jangomas, Albizia odoratissima, Acronychia padunculata, Chaetocarpus castanicarpus, Maesa paniculata, Crypteronia paniculata, Streblus asper and Mussaenda roxburghii were also found common in the study area. The findings will create baseline information of regenerating tree species, composition, diversity and population structure which can be used for monitoring future changes as well as taking policy decisions for the management of this Wildlife Sanctuary.&#x0D; J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 1-12

Успішність природного поновлення деревних порід на вітровальних ділянках в Українських Карпатах

Досліджено процес природного поновлення деревних порід на 42 вітровальних ділянках в Українських Карпатах, які розташовані на території 12 державних лісогосподарських підприємств та установ природно-заповідного фонду України у 15 типах лісу. Проаналізовано видовий склад і частоту трапляння самосіву та підросту окремих деревних порід на досліджених вітровальних ділянках: на пробних площах переважає ялина європейська, частка якої становить 23,7 % від загальної кількості самосіву і підросту, бук лісовий (21,1 %), ялиця біла (13,5 %) та клен-явір (11,3 %). Найрідше трапляється підріст дуба звичайного (0,03 %), дуба червоного (0,1 %), липи серцелистої (0,2 %), черешні (0,3 %), сосни звичайної (0,4 %), в'яза шорсткого (0,8 %) та клена гостролистого (0,8 %). На 24 досліджених вітровальних ділянках Українських Карпат виявлено добре природне поновлення деревних порід, на вісьмох – задовільне, на дев'ятьох – недостатнє і лише на одній – незадовільне.

Развитие нижних ярусов растительности под пологом тропического леса в условиях Вьетнама

The article presents the study results of natural regeneration of tree species on post-agrogenic lands and lands of former settlements in Vietnam. The experiment was carried out on the lands of the Cuc Phuong National Park, previously affected by management impact. Two experimental sites were selected: lands of former settlements and post-agrogenic lands. Methods developed by the Vietnamese scientists, as well as by the staff of the Forestry Department of the Saint-Petersburg State Forest Technical University have been used when laying out study plots, carrying out research, and processing the results. The studies have revealed that the undergrowth composition on the lands of former settlements is relatively complex. The number of species presented in the undergrowth composition ranges from 2 to 9. These species are pioneers at the initial stage of woody vegetation recovery on the lands of former settlements and they are of great environmental importance, though have a short life cycle. Species having a long life cycle are also found in the undergrowth. They are usually light-demanding, fast-growing and competitive with the other species for nutrients and light. In adulthood, they are presented in the stand composition. The presence of thesespecies increases the tree species diversity and broadly improves the stability of plantation. The undergrowth composition on the post-agrogenic lands is relatively simple. The number of species presented in it varies from 2 to 4, which is twice lower, than on the former settlements lands. These plants have a short life cycle, little economic value and low ability to compete for light and nutrients. Species that have a long life cycle are absent on the post-agrogenic lands. Viable and high undergrowth of seed origin prevails both on the lands of former settlements and on post-agrogenic lands. At both sites, the species diversity of the live ground coverand shrub layer is small and pretty much the same. The live ground cover is represented by herbs and sub-shrubs, and the shrub layer – by shrubs. These are light-demanding and fastgrowing species. The average projective coverage of live ground cover and shrub layer in both sites exceeds 85 %, which complicates the development of woody species undergrowth. In general, undergrowth, live ground cover, and shrub layer on the lands of former settlements are more diverse in terms of species composition and structure, than on the post-agrogenic lands. However, the density of the undergrowth in both areas is insufficient for the formationof further highly productive tropical phytocenosis. In this regard, it is necessary to carry out assistance measures for the subsequent successful reforestation on both types of lands.For citation: Beliaeva N.V., Nguyen Thi Thu Huong, Danilov D.A., Gryazkin A.V. Development of the Vegetation Lower Layer under the Tropical Forest Canopy in Vietnam. Lesnoy Zhurnal [Russian Forestry Journal], 2019, no. 6, pp. 39–51. DOI: 10.17238/issn0536-1036.2019.6.39

Distribution, effect and utilization of Mikania micrantha on livelihood: Case study of Janakauli buffer zone community forest of Chitwan National Park

Forest of lowlands is heavily impacted by invasive plants species, particularly Mikania micrantha which is also considered as one of the most invasion species. So, it became essential to understand effects of Mikania to user and indigenous vegetation; however the studies were confined to appraising the distribution, effect and utilization of Mikania micrantha on the livelihood of buffer zone of the Chitwan National Park. Vegetation survey, key informant interview, focus group discussion, direct observation and stratification were conducted. GPS points were recorded and the distribution map of Mikania was made by using ArcView GIS 10.1 and has been found throughout the Community Forest. Regression analysis showed that the number of plant regeneration of native tree species decreases by 0.530 unit with every 1 unit increment in Mikania crown cover. The study used a questionnaire survey to 118 households in the CNP of Nepal. The results indicate that the invasion of M. micrantha have negative effects on the community livelihood in the study area. Basic forest products such as fodder and fuel wood have become scarce as a result of reduction in the native plants. Only 6.78% of the users utilize Mikania for household purpose like briquettes fuel, fodder, medicine and manure. The losses of other plant species have severe effect to biodiversity so control measure with utilization should be taken as the most needed action. Regular assessment and monitoring of Mikania effect is necessary to understand the problem and its impact on biodiversity of lowland forest of Nepal.