Ecological and morphological features of Rhodiola rosea L. in natural populations in the Altai Mountains

The paper presents the results of the comprehensive study of Rhodiola rosea L. in natural populations in the Altai Mountains. The phytocoenotic confinement, demographic structure, and morphological characters of coenopopulations of Rh. rosea were studied in different ecological and coenotic conditions in the Chemal and Kosh-Agach regions of the Republic of Altai. Correlation between the morphometric parameters and their calculated values for the shoot and sex of the studied individuals, as well as environmental factors, was revealed. Rhodiola rosea L. is a valuable medicinal plant used for functional diseases of the central nervous system. At present, the natural reserves and areas of natural growth of the golden root have decreased significantly. The species is included in the Red Data Book of the Russian Federation (2008) and many regional Red Data Books of Siberia. In the Altai Mountains, Rh. rosea is widespread throughout the highlands, where it has occupied a wide range of habitats. The study showed that the highest values of ecological and effective density are characteristic of coenopopulations which are part of various hygrophytic variants of alpine and subalpine miscellaneous herbs with a high total projective cover of the herbaceous layer (CP 1, 2, 3, 4). The lowest values were found for coenopopulations growing in communities with a scarce herbaceous layer or dense shrub layer, and on steep gravelly slopes with crumbling soil and nonuniform moisture distribution (CP 5, 6, 8, 9). The studied coenopopulations are normal, full-membered, or incomplete-membered (some of them lack postgenerative individuals). In terms of the ontogenetic spectra, they are mainly left-sided, with a predominance of young generative individuals (CP 4, 5, 7) or bimodal, with an additional peak for old generative individuals (CP 2, 3, 6, 8). Male and female individuals Rh. rosea differ in many morphometric characters of the generative shoots. In some coenopopulations (CP 2, 3, 6, 9), male and female individuals show multidirectional deviation of characters compared to the totality, which indicates that in different environmental conditions these characters are not only genetically determined but can also be related to the sex of individuals.

TRANSFORMATION OF THE HERBACEOUS LAYER OVER 20 YEARS OF RESTORATION SUCCESSION IN BROAD-LEAVED FORESTS WITH LIANAS IN THE SOUTH OF PRIMORYE TERRITORY

The structure of herbaceous layer in the conditionally-indigenous mixed broad-leaved type of forest with lianas and its change for 1998-2018 are analyzed. Research was carried out at the ecological profile "Gornotayozhniy" (Ussuriysky district, Primorye Territory). A general description of phytocoenoesis is given. Complexes of microgroups of the herbaceous layer, united by the similarity of species composition, life forms and seasonal development, have been identified and characterized. Cartographic schemes of the herbaceous layer with the placement of microgroups at the beginning of research and after 20 years were compiled. It has been established that in the structure of herbaceous layer of forest ecosystems the directions of regular changes caused by the course of the forest-forming process are clearly traced.

State of Cenopopulations of Trommsdorffia ciliata (Thunb.) H.S. Pak (Asteraceae) in the Plant Communities of the Lower Reaches of the Ussuri River

The paper presents the results of studying the structure and state of four cenopopulations of the rare species Trommsdorffia ciliata (Thunb.) H.S. Pak in the valley of the lower reaches of the Ussuri River. The density of the studied cenopopulations is from 8 to 27 ind./m2. All studied cenopopulations are normal and incomplete. The absence or small number of juveniles in the ontogenetic spectrum of the studied cenopopulations is associated with a high projective cover of the herbaceous layer, which prevents the survival of this age group. According to the absolute maximum of ontogenetic groups of adult plants of all cenopopulations, Trommsdorffia ciliata are classified as young normal ones, where the maximum falls on individuals of the virginal state. An evaluation of population and organismic signs of the state of the studied cenopopulations showed that the most favorable conditions for the growth of Trommsdorffia ciliata are formed in a moist sedge-grass-herb meadow in the vicinity of Lonchakovo village. The measures for the protection of Trommsdorffia ciliata that are to include in the Red Book of the Khabarovsk krai (2019), to inhabit in a protected area and are to control the state of the known population of this species have been cited.

Climate and Management Factors Underlying Changes in Beech Forest Herbaceous Layer Plant Communities in the Polish Eastern Carpathians

The herbaceous vegetation and forest stand characteristics in European beech forests growing in the Polish part of the Eastern Carpathians have changed over the last 40 years. This has been influenced by many factors, including land-use change, forest management and climate change. This study investigates changes in forest cover and structure and the associated changes in herbaceous layer plant communities and seeks to elucidate whether and how beech forest herbaceous layer communities have been affected by climate change. The study used information from archival and current land cover maps, semi-permanent sampling plots, forest management plans for the Forest Districts of Brzozów, Lesko and Ustrzyki Dolne and meteorological weather station data compiled for three study periods of herbaceous vegetation (1970s, 2000s, 2010s). In the study area, the regular shelterwood system was changed to an irregular shelterwood system that produces stands with a complex overstorey structure. The results revealed the important role of light availability in shaping the species composition of the herbaceous layer in semi-natural Carpathian beech forests, which was strongly related to the course of management activities. An overall decrease in the number of species during the 2010s is linked to the ageing of beech forests, increased intensity of management activities in ageing stands, competition from understorey vegetation and lower soil moisture that can be linked to climate change. Our study partially supports the existing findings that more manipulative forest management systems can play an important role in countering the current and expected effects of climate change on the forest ecosystem because of the low degree of spatial differentiation of the stand’s structure (developmental stages). Therefore, foresters managing the structure of stands should strive to create a forest structure with high variability of developmental stages on a regional scale.

Tree – Open Grassland Structure Drives Carbon And Nitrogen Cycling In Mediterranean Wood Pastures of The Iberian Peninsula

Purpose: Mediterranean wood pastures are the largest agroforestry system in Europe. Traditional silvo-pastoral uses shaped these systems into a mosaic of trees and open grassland. However, little is known about how this structure may influence ecosystem carbon (C) and nitrogen (N) dynamics, considering different canopy types and interactions with the herbaceous layer.Aims: To unravel the canopy effect on C and N dynamics (1) under representative canopy types, including traditional Quercus stands and Pinus pinea L. plantations; and (2) in interaction with the herbaceous plant functional types (PFT).Methods: We analysed C and N content and the isotopic natural abundance on soil and plant materials at the open grassland and under the different tree canopies.Results: Under the canopy, soil C and N content, and N availability for the herbaceous layer increased. The canopy effect performed differences between Quercus and P. pinea plots, as detected on the belowground biomass C content. Also, the canopy effect was more pronounced with increasing environmental constraints, highlighting the relevance of trees in more restrictive environments. PFT ecophysiological characteristics interacted with tree canopies, as reflected the enhanced efficiency taking-up N, and/or exploiting symbiotic N of grasses, which was probably one of the causes of their dominancy under the canopy, at higher N availability.Conclusion: Changes in the tree coverage and tree species will significantly change ecosystem C and N storage and cycling. Therefore, it is highly advisable to preserve a balance between trees and open grassland, and traditional Quercus stands, to keep ecosystem services provisioning.

Phytoindication assessment of the effect of reconstruction on the light regime of an urban park

The ecological restoration of urban parks is used to increase their recreational attractiveness, improve air quality, mitigate urban heat island effects, improve stormwater infiltration, and provide other social and environmental benefits. The dynamics of plant communities after urban forest restoration requires investigation. The study assessed the impact of urban park reconstruction on the state of grass cover, phytoindication of changes in light regime caused by park reconstruction and found out the dependence of reliability of phytoindication assessment on the number of species in the relevant area. The study was conducted in the recreational area of the Botanical Garden of the Oles Honchar Dnipro National University (Ukraine). A tree plantation was created after the Second World War in the location of a natural oak forest. In 2019, a 2.8 ha area of the park was reconstructed. The samples were taken within polygons, two of which were placed in the reconstruction area and two of which were placed in a similar section of the park where no reconstruction was performed. During the reconstruction process, walkways were rebuilt, shrubs were removed, old, damaged trees were removed, and tree crowns were trimmed. Juvenile trees were planted in place of the removed old trees. Old outbuildings, which greatly impaired the aesthetic perception of the park, were also removed. Transport and construction machinery was involved in the reconstruction. A total of 65 plant species were found within the studied polygons. The number of herbaceous species in the park area after reconstruction was higher than without reconstruction. The crown closure in the reconstructed area was significantly lower than that in the untreated conditions. The phytoindication assessment showed that the light regime varies from the conditions suitable for the scyophytes (plants of typical foliage forests) to the conditions suitable for the sub-heliophytes (plants of light forests and shrubberies, or high herbaceous communities; lower layers are in the shade). The light regime in the park area after reconstruction was statistically significantly different from the regime in the untreated park area. The lighting regime after the reconstruction was favourable to sub-heliophytes, and without reconstruction the regime favoured hemi-scyophytes. Tree canopy crown closure negatively correlated with grass height and herbaceous layer projective cover. The tree canopy crown closure, grass height, and herbaceous layer projective cover were able to explain 86% of the phytoindication assessment of the lighting regime variation. These parameters negatively affected the light regime. The prospect of further research is to investigate the dependence of indicative reliability of the assessment of other environmental factors with the help of phytoindication depending on the number of species. In addition to the indication of traditional ecological factors it is of particular interest to clarify the aspect of the dynamics of hemeroby indicators as a result of park reconstruction.

Tree - Open Grassland Mosaics Drive the Herbaceous Structure and Diversity in Mediterranean Holm Oak Meadows

Background: Mediterranean holm oak meadows are semi‑natural savannah‑like agroecosystems that result from traditional silvo‑pastoral practices, which shaped these systems into a mosaic of trees and open grassland. However, traditional silvo-pastoral uses are declining with the implications that this may have on the herbaceous layer, a very biodiverse and valuable resource of these systems. Here, we aim at assessing the influence of the tree – open grassland mosaic on the structure, diversity, and composition of the herbaceous layer. Specifically, assessing the canopy effect (a) under representative Iberian canopy types, considering traditional Quercus species stands and Pinus pinea plantations at different locations; and (b) along seasonality. Results: The different components of the herbaceous layer performed differential responses to the presence/absence of tree canopies, as for instance shows the dominance of grasses under the canopy, while legumes and forbs were favoured in the open grassland. Also, there was a certain a reduction in the species richness in P. pinea dominated plots compared to plots dominated by Quercus species. There was a reduction of the aboveground biomass under the canopy at the more environmentally constrained location. Such canopy effects were generally more pronounced in spring that in autumn.Conclusion: It is highly advisable preserve the tree – open grassland mosaic and traditional Quercus species stands to maximize and preserve plant specific and functional diversity. The the optimum tree coverage might be dependent, not only on the primary ecosystem service (i. e. forage provision), but also on local conditions.

Nitrogen Fertilization, Stand Age, and Overstory Tree Species Impact the Herbaceous Layer in a Central Appalachian Hardwood Forest

Research Highlights: Herb-layer community composition, abundance, species richness, and Shannon–Wiener diversity index are shaped by nitrogen fertilization, disturbance history, and the overstory tree species in its immediate vicinity. Background and Objectives: While the herbaceous layer in deciduous forests is increasingly recognized for its importance in various aspects of forest ecosystem function, this study sought to describe the factors impacting the herbaceous layer. Specifically, this study’s objective was to quantify and compare herb-layer species composition, cover, and other community indices in watersheds with (a) different levels of N deposition, (b) different stand ages due to differing disturbance histories, and (c) different watershed aspects. This study also tested the hypothesis that herb-layer characteristics vary beneath tree species with contrasting nutrient dynamics (i.e., red and sugar maple). Materials and Methods: At the Fernow Experimental Forest in West Virginia (USA), the cover of all herb-layer species was recorded directly under nine red maple and nine sugar maple trees in each of four watersheds (WS): long-term fertilized WS3 and unfertilized WS7, both with a stand age of about 50 years, and two unmanaged watersheds with 110-year-old stands and opposite watershed aspects (south-facing WS10, north-facing WS13). Community composition and plot-level indices of diversity were evaluated with multivariate analysis and ANOVA for watershed-level differences, effects of the maple species, and other environmental factors. Results: In the fertilized watershed (WS3), herb-layer diversity indices were lower than in the unfertilized watershed of the same stand age (WS7). In the unfertilized watershed with the 50-year-old stand (WS7), herb-layer diversity indices were higher than in the watershed with the 110-year-old stand of the same watershed aspect (WS13). WS10 and WS13 had similar herb-layer characteristics despite opposite watershed aspects. The presence of sugar maple corresponded to higher cover and diversity indices of the herb-layer in some of the watersheds. Conclusions: Despite the limitations of a case study, these findings bear relevance to future forest management since the forest herb layer plays important roles in deciduous forests through its influence on nutrient cycling, productivity, and overstory regeneration.

Understory Vegetation Composition and Stand Are Mainly Limited by Soil Moisture in Black Locust Plantations of Loess Plateau

Forestry eco-engineering programs in China occupy 721.77 × 104 km2, among which plantations have a pivotal role in protecting the fragile ecological environment. Reforestation understory is often ignored because of the simple vertical structure. The importance of light in understory has been discovered. However, how other ecology factors (e.g., soil properties and geographical factors) influence understory composition and stratification remain unclear. In this study, we investigated the effects of understory composition and stratification on environmental factors in black locust plantations. We used systematic clustering analysis based on plant average height to describe understory stratification. The finding of this study was that black locust plantation understory consisted of three levels: (I) a low herbaceous layer (<80 cm), (II) a high herbaceous layer (80–130 cm), and (III) a shrub layer (>130 cm). Redundancy analysis indicated that soil moisture content and soil total phosphorus content were the largest contributors to the variation in understory vegetation composition. Soil moisture content, altitude, and soil organic carbon content were the largest contributors to the variation in understory stratification. Overall, by analyzing understory stratification and the relationship between soil and geographical factors, we gained a more comprehensive understanding of the interaction between understory and the microenvironment. This is especially important for reforestation management that maintains understory ecology function in the face of global climate change.