scholarly journals The small-scale variation of herb-layer community structure in a riparian mixed forest

2020 ◽  
Vol 28 (4) ◽  
pp. 390-398
Author(s):  
Y. O. Zhukova ◽  
N. V. Yorkina ◽  
V. S. Budakova ◽  
O. M. Kunakh

The ground vegetation layer is the most diverse plant community in forest ecosystems. We have shown the role of spatial variables, soil properties and overstorey structure in spatial variation of the herb-layer community in a riparian mixed forest . The research was conducted in the "Dnipro-Orils’kiy" Nature Reserve (Ukraine). The research polygon was located in the forest in the floodplain of the River Protich, which is a left tributary of the River Dnipro. Plant abundance was quantified by measuring cover within an experimental polygon. The experimental polygon consisted of 7 transects, each comprising 15 test points. The distance between the rows in the site was 3 m. At the site we established a plot of 45 × 21 m, with 105 subplots of 3 × 3 m organized in a regular grid. A list of vascular plant species was composed for each 3 × 3 m subplot along with visual estimates of species cover projection. The plant community was represented by 43 species, of which 18.6% were phanerophytes, 39.5% were hemicryptophytes, 9.3% were therophytes, 7.0% were geophytes. An overall test of random labelling revealed the total nonrandom distribution of the tree stems within the site. The species-specific test of random labelling showed the nonrandom segregated distribution of Acer tataricum, Pyrus communis, Quercus robur, and Ulmus laevis. Crataegus monogyna and Euonymus europaeus were distributed randomly. The nearest neighbour of Acer tataricum was less likely to be Ulmus laevis. There was no direct spatial connection between Acer tataricum and other trees. Crataegus monogyna, Pyrus communis, Quercus robur and Euonymus europaeus were not segregated from all other species. The nearest neighbour of Ulmus laevis was less likely to be Acer tataricum. Constrained correspondence analysis (CCA) was applied as ordination approach. The forward selection procedure allowed us to select 6 soil variables which explain 28.3% of the herb-layer community variability. The list of the important soil variables includes soil mechanical impedance (at the depth 0–5, 30–35, 75–80, and 95–10 cm), soil moisture, and soil bulk density. The variation explained by pure spatial variables accounted for 11.0 %. The majority of the tree-distance structured variation in plant community composition was broad-scaled. The spatial scalograms were left-skewed asymmetric. Significant relationship was found between the pure spatial component of the community variation and a number of phytoindicator estimations, most important of which were the variability of damping and humidity. Tree stand was obseerved to be a considerable factor structuring both the herb-layer community and spatial variation of the physical properties of soil.

2021 ◽  
Vol 82 ◽  
pp. 44-64
Author(s):  
Yuliia Zhukova ◽  
Nataliia Demchuk ◽  
Nadiya Yorkina ◽  
Yulia Dubinina ◽  
Dmytro Ganzha ◽  
...  

The role of spatial variables, soil properties and overstorey structure in spatial variation of the herb-layer community in a riparian mixed forest was shown. The research were conducted in the "Dnipro-Orils’kiy" Nature Reserve (Ukraine). The research polygon was laid in a forest in the floodplain of the River Protich, which is a left inflow of the River Dnipro. Plant abundance was quantified by measuring cover within experimental polygon. The experimental polygon consisted of 7 transects and each transect was made up of 15 test points. The distance between rows in the site was 3 m. At the site we established a plot of 45×21 m, with 105 subplots of 3×3 m organized in a regular grid. Vascular plant species lists were recorded for each 3×3 m subplot along with visual estimates of species cover projection. The plant community was represented by 43 species, of which 18.6% were phanerophytes, 39.5% were hemikriptophytes, 9.3% were therophytes, 7.0% were geophytes. An overall test of random labelling revealed the total nonrandom distribution of the tree stems within the site. Constrained correspondence analysis (CCA) was applied as ordination approach. The forward selection procedure allowed us to select 6 soil variables, which explain 28.3% of the herb-layer community variability. The list of the important soil variables includes soil mechanical impedance (at the depth 0–5, 30–35, 75–80, and 95–10 cm), soil moisture, and soil bulk density. The variation explained by pure spatial variables is equal to 11.0 %. The majority of the tree-distance structured variation in plant community composition was broad-scaled. The significant relationship was found between the pure spatial component of the community variation and a lot of phytoindicator estimations of which the variability of damping and humidity were of the greatest importance. Trees stand was demonstrated to be a considerable factor structuring both the herb-layer community and spatial variation of the physical properties of soil.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Gerong Wang ◽  
Yue Sun ◽  
Mo Zhou ◽  
Naiqian Guan ◽  
Yuwen Wang ◽  
...  

Abstract Background Herbs are an important part of the forest ecosystem, and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances. Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone, this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning. Results The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity, they were mainly determined by seasonal changes. Across the entire growing season, the species with the highest importance values in thinning treatments included Carex pilosa, Aegopodium alpestre, Meehania urticifolia, and Filipendula palmata, which dominated the herb layer of the coniferous and broad-leaved mixed forest. The number of species, Margalef index, Shannon-Wiener index and Simpson index all had their highest values in May, and gradually decreased with months. Pielou index was roughly inverted “N” throughout the growing season. Thinning did not increase the species diversity. Thinning can promote the total biomass, above- and below-ground biomass. The number of plants per unit area and coverage were related to the total biomass, above- and below-ground biomass. The average height had a significantly positive correlation with herb biomass in May but not in July. However, it exerted a significantly negative correlation with herb biomass in September. The biomass in the same month increased with increasing thinning intensity. Total herb biomass, above- and below-ground biomass showed positive correlations with Shannon-Winner index, Simpson index and Pielou evenness index in May. Conclusions Thinning mainly changed the light environment in the forest, which would improve the plant diversity and biomass of herb layer in a short time. And different thinning intensity had different effects on the diversity of understory herb layer. The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.


2000 ◽  
Vol 15 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Jacob O. Boateng ◽  
Sybille Haeussler ◽  
Lorne Bedford

Abstract This study examined 10 and 12 yr posttreatment effects of broadcast and spot application of glyphosate for site preparation on structural diversity, species richness and diversity, and crop tree growth in two boreal forest plant communities in northeastern British Columbia. At the broadcast-sprayed site, reduced dominance of the tall shrub layer was associated with increased structural diversity and increased richness of the herb layer 10 yr after treatment. At the spot-sprayed site, no significant differences in plant community structure or diversity could be detected after 12 yr. At both sites, glyphosate application increased the growth of planted white spruce (Picea glauca) seedlings without eliminating deciduous trees and shrubs. The results indicate that a single application of glyphosate to prepare sites for reforestation can improve crop tree performance without adversely affecting vascular plant community diversity. West. J. Appl. For. 15(1):15-26.


2011 ◽  
Vol 50 (No. 8) ◽  
pp. 364-370 ◽  
Author(s):  
M. Stránská

Between 1996&ndash;2002, successional dynamics on an abandoned pasture in Předn&iacute; Žd&iacute;rnice (lat. 50&deg;32&rsquo;N, long. 15&deg;40&rsquo;E) was examined. A 7-year study was performed on the abandoned mesotrophic pasture classified as Cynosurion T&uuml;xen 1947 at the start of the study. Two permanent plots (100 m<sup>2</sup>) were established and sampled three times a year; changes in plant species composition (species cover) and plant species diversity (species number) were studied. Species assemblages of the Cynosurus pasture were described, E1 (herb layer) and E2 (shrub layer) covers were calculated and a secondary succession in the plant community was evaluated. Abandonment caused the decrease in the cover of the species sensitive to shading &ndash; e.g. Taraxacum sect. Ruderalia, Trifolium repens, Lathyrus pratensis, Plantago major, Stellaria graminea, Vicia cracca. Contrary to this, the cover of Calamagrostis epigejos, Rubus sp., Galium album, Galium verum, Knautia arvensis, Veronica chamaedrys increased, probably due to their ability to spread by clonal growth and as a&nbsp;result of the competitive relationships in the plant community. A big production of Calamagrostis epigejos litter may be the outcome of a significant decrease (by 9%) in E1 cover (P = 0.04). Although the grassland was invaded by ruderal and weedy species (Apera spica-venti, Myosotis arvensis, Veronica arvensis) and by shrubs Crataegus sp. and Rosa sp. (an&nbsp;increase by 16%), an increase in species number was not significant. Phytosociologically, the Cynosurion T&uuml;xen 1947 community came closer to the Arrhenatherion Koch 1926 alliance.


2019 ◽  
Vol 88 (2) ◽  
Author(s):  
Wiktoria Hryń ◽  
Joanna Czarnecka ◽  
Ignacy Kitowski ◽  
Piotr Bartmiński ◽  
Robert Zubel

The grey heron (<em>Ardea cinerea</em>) is a good example of an engineering species that forms nesting colonies (called heronries) composed of up to a few hundred nests during the breeding season. It exerts strong pressure on surrounding vegetation, mainly because of the heavy input of organic matter and high eutrophication. The birds also alter light conditions through direct tree damage. We aimed to examine the influence of a grey heron breeding colony on the soil properties and functional composition of the herb layer in two different forest communities: a suboceanic pine forest and a riparian mixed forest. We also wanted to establish whether these changes would make the forest ecosystem more vulnerable to colonization by nonforest species with higher light and trophic demands. Small-seeded, light demanding eutrophic species showed a tendency to be more abundant under the nests in both forest types. The calculated odds ratio (OR) showed that the probability of the presence of nonforest species under the nests was 29.5 times higher than that in the control plots (56 plants species were analyzed). Additionally, the nonforest species appeared to have high light and trophic demand (OR of 12.3 for light demand; OR of 7.0 for trophic demand), which explains the species turnover observed in the bird-affected microhabitats.


2014 ◽  
Vol 30 (4) ◽  
pp. 311-322 ◽  
Author(s):  
Nic van der Velden ◽  
J. W. Ferry Slik ◽  
Yue-Hua Hu ◽  
Guoyu Lan ◽  
Luxian Lin ◽  
...  

Abstract:Monodominance in the tropics is often seen as an unusual phenomenon due to the normally high diversity in tropical rain forests. Here we studied Parashorea chinensis H. Wang (Dipterocarpaceae) in a seasonal tropical forest in south-west China, to elucidate the mechanisms behind its monodominance. Twenty-eight 20 × 20-m plots were established in monodominant and mixed forest in Xishuangbanna, Yunnan province. All individuals ≥1 cm stem diameter and 16 soil variables were measured. Parashorea chinensis forest had a significantly higher mean tree dbh compared with mixed forest. Diversity did not differ significantly between the two forest types. However, within monodominant patches, all diversity indices decreased with an increase in P. chinensis dominance. Floristic composition of P. chinensis forest did differ significantly from the mixed forest. These differences were associated with more fertile soils (significantly higher pH, Mn, K and lower carbon pools and C:N ratio) in the P. chinensis forest than the mixed forest. In contrast to current paradigms, this monodominant species is not associated with infertile, but with fertile soils. Parashorea chinensis seems to be especially associated with high manganese concentrations which it can tolerate, and with edaphic conditions (water, K) that allow this tall and exposed emergent species to maintain its water balance. This is in contrast with most previous studies on monodominance in the tropics that found either no effect of soil properties, or predict associations with nutrient-poor soils.


Hacquetia ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 81-97
Author(s):  
Kiril Vassilev ◽  
Momchil Nazarov ◽  
Nikolay Velev

AbstractMantle vegetation includes plant communities dominated mostly by shrubs and occurs in habitats where the typical tree layers meet difficulties to evolve. This study was conducted in three areas of Bulgaria – Western Balkan Range, Western Sredna Gora Mt. and the Fore-Balkan. Numerical classification and ordination were performed by PC-ORD and JUICE software packages. Diagnostic species were determined by calculating the Phi-coefficient. Two associations and one plant community of the Berberidion alliance were recognized – Corno-Ligustretum Horvat ex Trinajstić ---amp--- Z. Pavletić 1991, Pruno spinosae-Ligustretum vulgaris Tüxen 1952 and Elytrigia repens-Crataegus monogyna community. The latter considered as a successional stage of shrub encroachment into the grasslands. Its species composition is very close to that of the ass. Corno-Ligustretum. The species composition of ass. Pruno-Ligustretum represents a mixture of species characteristic for dry and mesic grasslands, fringe and forest vegetation. The Crataego-Prunetea class is still poorly studied in Bulgaria and much more data from all regions in the country have to be collected.


2019 ◽  
Vol 38 (3) ◽  
pp. 253-272
Author(s):  
Olexander Zhukov ◽  
Olga Kunah ◽  
Yulia Dubinina ◽  
Yulia Zhukova ◽  
Dmytro Ganzha

AbstractThe tree species composition can influence the dynamics of herbaceous species and enhance the spatial heterogeneity of the soil. But there is very little evidence on how both overstorey structure and soil properties affect the spatial variation of the herb layer. The aim of this study is to evaluate the factors of the soil and overstorey structure by which it is possible to explain the fine-scale variation of herbaceous layer communities in an Eastern European poplar-willow forest. The research was conducted in the “Dnipro-Orils’kiy” Nature Reserve (Ukraine). The research polygon (48°30′51″N, 34°49″02″E) was laid in an Eastern European poplar-willow forest in the floodplain of the River Protich, which is a left inflow of the River Dnipro. The site consists of 7 transects. Each transect was made up of 15 test points. The distance between rows in the site was 3 m. At the site, we established a plot of 45×21 m, with 105 subplots of 3×3 m organized in a regular grid. The adjacent subplots were in close proximity. Vascular plant species lists were recorded at each 3×3 m subplot along with visual estimates of species cover using the nine-degree Braun-Blanquet scale. Within the plot, all woody stems ≥ 1 cm in diameter at breast height were measured and mapped. Dixon’s segregation index was calculated for tree species to quantify their relative spatial mixing. Based on geobotanical descriptions, a phytoindicative assessment of environmental factors according to the Didukh scale was made. The redundancy analysis was used for the analysis of variance in the herbaceous layer species composition. The geographic coordinates of sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Two measurements of the overstorey spatial structure were applied: the distances from the nearest tree of each species and the distance based on the evaluation of spatial density of point objects, which are separate trees. In both cases, the distance matrix of sampling locations was calculated, which provided the opportunity to generate eigenvector-based spatial variables. A kernel smoothed intensity function was used to compute the density of the trees’ spatial distribution from the point patterns’ data. Gaussian kernel functions with various bandwidths were used. The coordinates of sampling locations in the space obtained after the conversion of the trees’ spatial distribution densities were used to generate a set of orthogonal eigenvector-based spatial variables, each of them representing a pattern of particular scale within the extent of the bandwidth area structured according to distance and reciprocal placement of the trees. An overall test of random labelling reveals the total nonrandom distribution of the tree stems within the site. The unexplained variation consists of 43.8%. The variation explained solely by soil variables is equal to 15.5%, while the variation explained both by spatial and soil variables is 18.0%. The measure of the overstorey spatial structure, which is based on the evaluation of its density enables us to obtain different estimations depending on the bandwidth. The bandwidth affects the explanatory capacity of the tree stand. A considerable part of the plant community variation explained by soil factors was spatially structured. The orthogonal eigenvector-based spatial variables (dbMEMs) approach can be extended to quantifying the effect of forest structures on the herbaceous layer community. The measure of the overstorey spatial structure, which is based on the evaluation of its density, was very useful in explaining herbaceous layer community variation.


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