Effects of the Invasive Tree Species Ailanthus altissima on the Floral Diversity and Soil Properties in the Pannonian Region

Tree-of-heaven (Ailanthus altissima) is one of the most dangerous and widespread invasive woody plant species in Europe. Despite the fact that A. altissima is in the focus of an increasing number of research projects, the impact of its mass spread on native vegetation, its diversity, and changes in soil quality are still incomplete. The current study addresses the effects of this invasive species on plant diversity and soil parameters simultaneously. The main objective of our research is to determine the impact of cover and mass of A. altissima on the diversity of each forest layer; the examined soil parameters and on other selected environmental variables. For botanical and pedological investigations we selected nine A. altissima-dominated sites in Central Europe, in the Pannonian Biogeographical Region. Based on our results, it can be stated that fully grown A. altissima-dominated stands can displace other taxa by their shading and allelopathy, thereby reducing canopy layer diversity. The increase in the species richness of the shrub layer had a positive correlation with the diversity of the floor layer and also with the humus and ammonia content of the soil. As the diversity of shrub layer and floor layer positively correlated with many soil parameters, the diverse vegetation of these layers can represent a potential opportunity for the regeneration of areas infected with A. altissima.

Illuminance under canopy in different types of forest in the northern taiga

The illumination under the canopy in different types of pine and spruce forests is considered. The research was carried out in different points of the Northern taiga of the Arkhangelsk region. Illumination was measured using a luxmeter in different directions: at the level of the moss-lichen layer, at the level of the grass-shrub layer and at a height of 1.3 m; at different distances from the tree trunk; at different distances from the edge of the forest. Illumination in pine forests at the level of the moss-lichen layer is 2.3 times higher than in spruce forests. Under the canopy of spruce forests, it is 1–3%, and in the pine forests, 3–9% of the illumination in the open. Illumination from tree trunks to the edge increases in pine and spruce forests equally. The lowest illumination is observed at the level of the moss-lichen layer, then it increases to the grass-shrub layer, and then practically does not change. However, the difference between pine and spruce forests is consistently high 47%. The decrease in illumination in the tree stand as it moves away from the edge in blueberry pine forests is observed up to a distance of 10 m from the edge, and in blueberry spruce forests up to 6 m.

The Characteristics of Habitat, Functional Traits and Medicinal Components of Eucommia Ulmoides From Guizhou

To find out the genuine characteristics of Eucommia ulmoides produced in Guizhou.The habitat, functional characters and the content of medicinal components of Eucommia ulmoides in Guizhou were studied by using the method of sample survey combined with typical survey, related laboratory experiments and quantitative analysis. The results showed that the yield of Eucommia ulmoides plantation in Guizhou was divided into low altitude, low middle and high temperature rain slope latitude mixing, short sunshine type(A type), medium altitude, low longitude and latitude, high temperature rain, positive oblique steep slope, medium sunshine type (B type), Middle altitude, low longitude and latitude, moderate high temperature rain, Shady side and Sunny side have gentle deflection steep slope, medium sunshine type (C type), High altitude, low longitude and latitude, low temperature moderate rain, positive gentle slope, long sunshine type (D type); Different types of Eucommia ulmoides plantation, Different habitat quality, B type is intensity karst rocky desertification habitat, A type is potential karst rocky desertification habitat,The C and D types are light and moderate rocky desertification areas respectively, The species diversity of shrub layer in Eucommia ulmoides plantation was higher in D type and B type, A type and C type followed; There was no significant difference in root carbon content and leaf nitrogen content in 4 types of Eucommia ulmoides plantation, Among the four types of A、B、C、D, there were significant or extremely significant differences in other indexes of plant functional traits; Both genipinic acid and aucubin had the highest content of root bark, followed by trunk bark and lowest leaves, Chlorogenic acid is the opposite, The content of geniposide was higher in trunk bark and lower in root bark and leaves; Genipinic acid is higher in D type, Aucubin is higher in A and D type, Chlorogenic acid has higher leaves content in B type, Geniposide was the highest in trunk bark of D type; The element enrichment coefficient K and Mn leaves are the largest, the largest in trunk bark is Ca and Zn, Fe root bark is the largest; Effects of soil potassium, phosphorus, pH value and bulk weight on the functional traits of Eucommia ulmoides were significant. The contents of medicinal components in root bark, trunk bark and leaves was influenced by species diversity of shrub layer, The contents of geniposide in root bark, aucubin in root bark and trunk bark, genipinic acid in bark and chlorogenic acid in leaves were particularly affected by soil physical and chemical indexes and metal element contents, The functional traits of Eucommia ulmoides can affect the content of medicinal components in root bark, trunk bark and leaves, Especially on the root bark, trunk bark and leaves in the content of aucubin content; The content of medicinal components of Eucommia ulmoides was high and stable. The above research results have important theoretical reference significance for the cultivation of Eucommia ulmoides and the cultivation of target medicinal components and the comprehensive exploitation and utilization of resources.

Assessment of Natural and Forest Reclaimed Forage Lands in Semi-Desert Conditions in Southern Russia

Haphazard use of pastures has become one of the factors of disturbance of their natural vegetation. Therefore, forest reclamation works were carried out and significant areas of strip plantations of shrubs were created in the Caspian Sea region in the mid-20th century. In the arid zone of Russia, one of the most important tasks in the field of scientific provision of protective afforestation is the improvement of methods and techniques of arrangement, increasing longevity and environmental, agricultural, and utilitarian efficiency of plantations. This study aims to determine the long-term impact of afforestation on the functioning of pasture ecosystems. The influence of tree and shrub layer on biodiversity and productivity of vegetation cover of pastures was also studied. The research objects are plantations growing on the reclaimed pastures. The research is based on the materials of biomonitoring and field experiments using standard methods of forest inventory and geobotanical survey. Rectangular-shaped test plots of 0.25–0.30 ha were laid out for the study of forest plots. Test plots were used for a detailed description of the location, soil composition, time, method, and technology of plantation development, as well as a comprehensive assessment of the growth and longevity of tree and shrub crops. Data from key plots were used to study the successional processes of vegetation cover. The research results have shown that deep plowing preparation of soil to obtain high results in rooting, preservation, and growth of shrub species has an advantage over other soil preparation technologies in the semi-desert zone. It was found that the shrub layer up to 45 years old retains its productive and generative abilities. Pasture protection belts from Haloxylon aphyllum and reclamation and fodder plantations from Krascheninnikovia ceratoides and Calligonum aphyllum have a high cenosis potential and stability. In this case study, in semi-arid regions, afforestation with shrubs is the best way to improve and restore pastures. For citation: Rybashlykova L.P., Lepesko V.V. Assessment of Natural and Forest Reclaimed Forage Lands in Semi-Desert Conditions in Southern Russia. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 37–48. DOI: 10.37482/0536-1036-2021-3-37-48

How do invasive trees impact shrub layer diversity and productivity in temperate forests?

• Key message Invasive tree species alter taxonomic diversity and functioning of forest shrub layers: Prunus serotina increases shrub layer biomass two to three times but decreases its biodiversity, Robinia pseudoacacia slightly increases shrub layer biomass and has no effect on its biodiversity, while Quercus rubra both biomass and biodiversity of the shrub layer. • Context Although the impact of invasive trees on understory biodiversity is known, very little data exist about their influence on shrub layer biodiversity and productivity. • Aims To assess impacts of Prunus serotina Ehrh., Quercus rubra L., and Robinia pseudoacacia L. on shrub layer aboveground biomass, species composition, and alpha diversity. • Methods We measured stand structures in a set of 168 study plots established in Wielkopolski National Park (W Poland), and we compared biomass and diversity metrics using generalized mixed-effects linear models. • Results We found the lowest aboveground biomass of shrub layers in Q. rubra forests. P. sylvestris forests invaded by P. serotina had two to three times higher aboveground biomass than non-invaded forests. R. pseudoacacia forests had 27.8% higher shrub layer biomass than Quercus-Acer-Tilia forests. We found negative impacts of Q. rubra and negligible impacts of R. pseudoacacia on shrub layer alpha diversity metrics. However, the effect of Q. rubra was similar to native F. sylvatica. P. serotina negatively affected functional diversity, but its effects were lower in rich P. sylvestris forests than in poor P. sylvestris forests. • Conclusion The introduction of alien tree species alters ecosystem services and species diversity of shrub layers. The direction and magnitude of these alterations are alien species-specific and context-dependent. Therefore, their management should account for their impacts.

Study on Urban Landscape Green Space -- A Case Study of Longquanshan Park

Studying on Qinglongshan Forest Park in Wuhan by typical plot method, 15 typical plots in the park were investigated, and the species richness index, diversity index, evenness index, frequency and important value index were calculated. The results showed that there were 139 species of woody plants belonging to 46 families and 97 genera, including 41 species of evergreen trees, 32 species of deciduous trees, 62 species of evergreen shrubs, 25 species of deciduous shrubs, and 4 species of bamboo belonging to 1 family, 3 genera. Species richness index and Simpson diversity index were all expressed as tree layer > shrub layer, evergreen species > deciduous species. Pielou evenness was tree layer > shrub layer. This study can provide some reference for understanding the existing plant status of forest parks, carrying out science popularization, scientific research, protection and improvement of forest landscape quality.

Study on Diversity and Protection Countermeasures of Zhongshan Park in Wuhan City

Park green space is an important part of garden green space, concentrated expression of the diversity of urban plants. In order to explore the diversity of plants in the park, a typical site in Zhongshan Park in Wuhan was selected for this survey. The species importance, richness index, diversity index and evenness index were used to analyze the characteristics of plant diversity.There are a total of 184 plants of 114 genera and 64 families in Wuhan Zhongshan Park. Among them, there are 86 species of plants of 40 families and 64 genera, 60 species of plants of 26 families and 38 genera, and 26 species of herbs, 11 families and 15 genera.The richness was herb layer > tree layer > shrub layer.Pielou uniformity was herb layer > tree layer > shrub layer;Shannon-wiener diversity was herb layer > tree layer > shrub layer.Simpson diversity was herb layer > tree layer > shrub layer.The diversity of herbaceous plants in the park is high, and the index of shrub layer is generally low, with few species. Plants in the park grow well, some plants are not evenly distributed.