The composition, species richness and species pool size of mono- and oligodominant forest stands of the Western Caucasus

2018 ◽  
pp. 3-18
Author(s):  
V. V. Akatov
Keyword(s):  
Species Richness ◽  
Plant Cover ◽  
Species Abundance ◽  
Pool Size ◽  
Species Pool ◽  
Forest Stands ◽  
Western Caucasus ◽  
Number Of Species ◽  
Dominance Structure ◽  
The Western Caucasus

There is an opinion that the pressure of competition in the plant communities of stable and productive habitats leads to the decrease in evenness of structure of species abundance and species richness up to the monopolization of plots by the most successful competitor (Huston, 1979; Bengtsson et al., 1994). Hence, between the species richness of phytocoenoses and relative density of individuals of dominant species (RDD), negative dependence should be observed. However, according to another view, the number of species and structure of their abundance are determined by the different processes. The number of species is determined by the species pool size and the rate of species immigration, while the abundance structure — by the competition (Stirling, Wilsey, 2001; Ma, 2005; Wilsey, Stirling, 2007). In particular, in some communities a decrease of RDD leads to an increase in abundance of subdominant species and to oligodominant structure. These changes in relative abundance could occur without changes in species richness. Therefore these variables could be weakly related (Ma, 2005; Wilsey, Stirling, 2007; Munson, Lauenroth, 2009). However, it is unclear how widely these scenarios are realized in the plant cover. The aim of our study was to examine the relationship between RDD, the dominance structure as a whole (mono- or oligodominant), the species richness and the size of the species pool in the forest stands of the Western Caucasus.

scholarly journals Sowing Mixtures of Native Plant Species: Are There Any Differences between Hydroseeding and Regular Seeding?

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2507
Author(s):  
Vilma Gudyniene ◽  
Sigitas Juzenas ◽  
Vaclovas Stukonis ◽  
Egle Norkeviciene
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Growth Traits ◽  
Plant Cover ◽  
Species Abundance ◽  
Legume Species ◽  
Competitive Growth ◽  
Native Plant ◽  
Native Plant Species

Hydroseeding is a convenient, low-cost way to plant seeds. Traditionally, fast-growing commercial species that are cheap to obtain are preferred in hydroseeding, while native species have limited use. Nowadays, the use of native species is often desired in revegetation projects. However, there is a paucity of information about hydroseeding native species in Northern areas of Europe. Therefore, we aimed to determine whether hydroseeding has any effects on native plant cover formation, species richness and abundance, the development of plant morphological features, or aboveground biomass. A total of 40 native plant species in Lithuania were sowed using hydroseeding and regular seeding. The experimental plots were assessed for two years. The results show a relatively small and short positive effect of hydroseeding on plant cover formation. No significant differences were found in species richness between the sowing treatments. However, a comparison of species composition revealed significant differences between the sowing treatments that were more associated with species abundance than species diversity. Hydroseeding was favoured by legume species, such as Onobrychis viciifolia, Ononis arvensis, Lotus corniculatus, and Trifolium medium, while Festuca rubra favoured the regular seeding treatment. Overall, our findings emphasize that legume species that display more competitive growth traits should be included in the seed mixture in lower proportions when hydroseeding is applied.

scholarly journals Probing the troublesome peaked relationship between avian species richness and natural land cover

2021 ◽  
Author(s):  
Rafael Xavier De Camargo ◽  
David Currie
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Landscape Heterogeneity ◽  
New York State ◽  
Pool Size ◽  
Avian Species ◽  
Temperature Gradients ◽  
Species Pool ◽  
Natural Land ◽  
The Relationship

Abstract Context : Biodiversity models postulate that the relationship between richness and the proportion of natural land cover (pNLC i.e., not dominated by human uses) is: 1) monotonic positive, 2) reasonably strong , 3) consistent in different geographic areas . Earlier work examining 100-km 2 human-dominated landcover in Ontario, Canada, observed that surveyed avian species richness is a peaked function of pNLC. Objective : We tested whether the same relationship between avian species richness and pNLC is also observed in an independent geographic area that has similar biomes. We also tested whether the peaked relations might be caused by temperature gradients, gradients in the size of species pools, grain size in the analyses, and landscape heterogeneity. Methods : Using breeding bird atlases of Ontario (Canada) and New York State (USA), we estimated species richness in landscapes varying from 25 to 900 km 2 . We related richness to the pNLC in each landscape and examined the same relationships after controlling for temperature, habitat heterogeneity, and species pool size. Results : Landscape-level species richness is a peaked, and not very strong function of pNLC. The relationship is not an artefact of temperature gradients, species pool size, or land cover heterogeneity. Conclusions : The proposition that increased amounts of natural land cover promotes species richness is clearly true at the limit, in landscapes with relatively little (<30%) natural cover. In landscapes with higher amounts of natural cover, a certain amount of human-modified land covers can provide habitat for species that prefer open habitats.

scholarly journals Tree species richness as the element of structure and diversity in mixed stands of beech and valuable broadleaves

2012 ◽  
pp. 157-172
Author(s):  
Branko Stajic ◽  
Milivoj Vuckovic
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Woody Species ◽  
Forest Stands ◽  
Expected Number ◽  
Mixed Stands ◽  
Species Richness And Diversity ◽  
Number Of Species ◽  
Tree Species Richness ◽  
Ecological Unit

In our forest science and forest operations, the tree species richness and diversity of woody species in forest stands are most often evaluated based on the total number of tree species, which is a methodologically partly inadequate approach. For this reason, the quantification and the evaluation of diversity of woody species in mixed forests of beech with valuable broadleaves in the area of the National Park ?Djerdap? were analyzed by five different indices of tree species richness: number of species (S index), two indices of the species richness (R1 and R2), expected number of species in the sample with equal numbers of trees (E(S84)), and expected number of species in the sample with equal areas (E(S0,25ha)). The results showed that the level of woody species diversity in forest stands depended on the applied index characterizing the tree species richness. It was concluded that the tree species richness and diversity were the highest in the stands of ecological unit B (E(S84)=8.6 species) and in the stands of ecological unit G (E(S0,25ha)=9.4 species), and they were the lowest in the stands of ecological unit V (E(S84)=5.8 species, E(S0,25ha)=5.5 species).

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