scholarly journals Diversity of beetles (Coleoptera) in natural and planted saxaul forests (Haloxylon ammodendron) in the South Gobi Desert, Mongolia

ZooKeys ◽  
2020 ◽  
Vol 1000 ◽  
pp. 59-70
Author(s):  
Buyanjargal Batchuluun ◽  
Jens Wunderlich ◽  
Michael Schmitt

We investigated species composition and diversity parameters of beetle communities in two planted saxaul (Haloxylon ammodendron, black saxaul) forests in Southern Mongolia. We also studied nearby natural areas for comparison. Beetles were mainly collected by pitfall traps. 1064 individuals of 38 species of 22 genera in 4 beetle families were identified from planted plots. In comparison, a total of 1395 beetles belonging to 40 species of 24 genera in seven families were collected and identified from the natural saxaul plots. The most diverse beetle families were darkling beetles (Tenebrionidae, 18 species) and snout beetles (Curculionidae, 15 species) in planted and natural saxaul plots. We recorded several species (Apatophysis serricornis, Cephogenia chinensis, and Eumylada punctifera punctifera) which are associated with the saxaul tree. A darkling beetle, Anatolica potanini, was the dominant species in both natural and planted plots of the Nariin Zag forest. There were significant differences in the species richness and abundance between the planted and natural plots of the Ukhaa Zag forest. It is possible that the age of the plantation drove the differences. The higher values of diversity indices and species richness in the planted plots can be explained by the presence of rare species, represented by only one or two individuals. The planted plots and corresponding natural plots within each forest were more similar to each other in species composition and abundance than between forests.

2002 ◽  
Vol 32 (1) ◽  
pp. 38-51 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell

In northern forests, cryptogams (spore producing plants) occupy a key position in forest ecosystem diversity and function. Forest harvesting and silvicultural practices have the potential to reduce cryptogam diversity. This project uses four blocks that were mechanically site prepared, planted with a single conifer species, and subsequently subjected to five conifer release treatments: (1) motor-manual cleaning, (2) mechanical brush cutting, (3) aerial application of triclopyr, (4) aerial application of glyphosate, and (5) control (untreated clearcut). Five 10 × 10 m subplots were installed in each of the five treatment plots and the uncut forest on the four blocks. Botanical surveys were conducted before and 1–5 years after treatments. Species richness and abundance, Shannon's and Heip's indices, and rank abundance diagrams clearly show that richness and abundance were affected by silvicultural treatments. Vegetation management treatments resulted in significant reductions in cryptogam diversity, to the point that only a few colonists and drought-tolerant species remained. Cryptogam diversity was ranked in the following order: forest > clearcut > mechanical clearing > herbicide treatment. Herbicide treatments had the greatest initial effect on species richness, species abundance, and diversity indices. Cryptogam diversity showed signs of recovery 5 years after treatments. Missed strips (untreated areas) within a clearcut provided a refuge for remnant communities of forest cryptogams that could play a key role in the rehabilitation forest diversity.


2017 ◽  
Vol 147 (2) ◽  
Author(s):  
Pallieter De Smedt ◽  
Sam Van de Poel

Sand mining strongly alters the existing landscape, transforming an area into a mosaic of native (sand deposits) and foreign soils, strongly influencing biotic development. The method of restoration of such excavated areas is often debated: natural succession or active restoration. We investigated how natural succession shapes harvestman communities, as part of the soil-dwelling community. We sampled harvestmen over a continuous period of 14 months in 25 plots in an abandoned sand quarry in Belgium using pitfall traps. We found significant increases in harvestman activity-density, species richness and diversity with time since abandonment of the various sections of the quarry. After about 15 years, a drastic change in species composition was observed with the establishment of forest species that more strongly depend on humid conditions to complete their life cycle. Colonisation of harvestmen closely followed vegetation succession despite their limited mobility. We argue that natural succession could be a good management tool for restoring harvestman communities as well as those of other soil-dwelling invertebrates in abandoned sand quarries.


2004 ◽  
Vol 52 (1) ◽  
pp. 23 ◽  
Author(s):  
Sarah J. Hill ◽  
Kristine French

Exclosure plots were used to determine the effect of fire and grazing on the structure of a grassy-woodland community. Eighteen months after fire and fence treatments were applied, the species richness, cover and composition of shrubs, trees, herbs and grasses were assessed and compared to pre-treatment censuses. Unburned plots had fewer shrub species and a lower abundance of shrubs, indicating the importance of fire in promoting regeneration of shrub species. Eucalypt species were more abundant and richer following the wildfire burn in summer, suggesting timing of fires is an important aspect in the establishment of the canopy species. Interactions between fire and grazing were found for the abundance of eucalypts (although weak) and resprouting eucalypts, suggesting a subtle interaction between fire and grazing shortly after fire. There was no effect of grazing and no interaction effect between fire and grazing on shrub species richness and abundance or tree species richness and seedling abundance.All plots showed a change in species composition despite treatment, and 46 species (32% of total richness) were recorded only in the final survey. The high rainfall during the 18-month study is likely to be an important factor in facilitating the establishment of species following all disturbances. This may have ameliorated the impact of grazing as abundant food was available throughout the woodland. The interaction between fire and grazing may be more important in structuring these grassy communities during periods of lower rainfall.


2013 ◽  
Vol 145 (1) ◽  
pp. 61-76 ◽  
Author(s):  
Jaime Pinzon ◽  
John R. Spence ◽  
David W. Langor

AbstractSpiders (Araneae) were sampled in white spruce (Picea glauca (Moench) Voss (Pinaceae)) dominated stands from the ground and shrub layers, and from several overstorey strata to assess patterns in species composition and diversity (alpha and beta) along the vertical gradient (0–12 m above ground). Overall, 3070 adult spiders in 15 families and 76 species were collected, with the ground layer accounting for the highest species richness (40 species) followed by the mid-overstorey (36 spp.) and the shrub layers (33 species). Vertical stratification was apparent in the samples: richness clearly decreased with height, and species turnover between the ground, shrub, and mid-overstorey levels was evident, suggesting that species composition in each layer was highly distinctive. Within the mid-overstorey stratification was less obvious but both species richness and spider abundance were predicted significantly by height from the ground and branch size. Given the role of late-seral conifer stands for maintaining old-growth species, understanding diversity patterns across strata provides basic knowledge to support forest management decisions that effectively conserve spider species and assemblages. It is clearly important to include higher canopy layers in considering impacts of forestry on biodiversity in the boreal mixedwood.


2020 ◽  
Vol 63 (2) ◽  
pp. 75-90
Author(s):  
Elena Salerni ◽  
Debora Barbato ◽  
Cecilia Cazau ◽  
Lorenzo Gardin ◽  
Gianni Henson ◽  
...  

As a man-induced disturbance of forest ecosystems, thinning may affect biodiversity and other related ecological functions including fungal dynamics. In this context, a multidisciplinary EU-Life project was established in 2014 to evaluate the application of selective thinning in two Pinus nigra plantations areas of the Apennines (Monte Amiata and Pratomagno, Tuscany, Italy). Selective thinning had the aim to improve stands stability and growth rates, taking also into account the various components of soil biodiversity (flora, fungi, mesofauna, nematodes, microarthropods and bacteria). Here we present mushroom fruiting patterns previous to treatment in 2014 and the effect following the application of forest management (selective thinning and traditional thinning from below) in 2018. Boxplots were used to graphically represent intra and inter annual variations in species richness and abundance, while Principal Coordinates Analyses and multi-response permutation procedures based on Bray-Curtis dissimilarity matrix were applied to evaluate turnover in species composition before the management and after 4 years. A significant reduction of fungal richness and abundance after 4 years thinning impact was lacking in both study areas, testifying a certain degree of resistance and/or resilience of mushroom fruiting to forest management-related anthropogenic disturbance. Considering each study site separately, Monte Amiata and Pratomagno did not show one uniform trend but differed significantly in their response to management: while in Pratomagno relevant inter-annual differences were present only in a few cases, an underlining significant variation both for species richness and abundance was registered in Monte Amiata for all treatment types among years (inter-annual variation) but not within each year (intra-annual variation). Only in Pratomagno turnover in species composition in selective thinning differed somewhat from the traditional treatment in 2018, showing that a process is underlying but still potentially masked by other variables. Due to the nature of macrofungi, a longer study period (more than 4 years post treatment impact) as well as the application of a more intense forest management, could be necessary to highlight and disentangle any possible trends in fungal fruiting in artificial stands


2021 ◽  
Vol 43 ◽  
pp. e56924
Author(s):  
Pablo Henrique dos Santos Picapedra ◽  
Cleomar Fernandes ◽  
Gilmar Baumgartner ◽  
Paulo Vanderlei Sanches

We investigated changes in the species richness, abundance, and composition of the zooplankton community in response to the formation of a small reservoir in the Caveiras River, southern Brazil. Zooplankton were collected using a motor-pump and a plankton net (68 μm mesh), with 600 L of water filtered per sample. Sampling occurred during the pre- (April, August, and December 2011) and post-impoundment (July and October 2013, and January 2014) phases of the Caveiras River. We identified 86 taxa in this study, and rotifers were the predominant group. The species richness and abundance of the zooplankton increased after the filling of the reservoir. Furthermore, the zooplankton community showed a clear change in the species composition between the phases before and after the formation of the reservoir, with the emergence of typical planktonic species. Changes in the structure of the zooplankton community were related to changes in limnological characteristics due to the impoundment of the river, mainly in the availability of food and in the concentration of nutrients.


2020 ◽  
Vol 13 (1) ◽  
pp. 1-9
Author(s):  
Ziyad Jemal ◽  
Zerihun Girma ◽  
Girma Mengesha

Background: Birds are one component of biodiversity. Ethiopia is rich in biodiversity resources. The avian diversity record is far from complete. There is no scientifically documented information on bird species composition and abundance at Nensebo forest. The objective of the study was to assess species composition, relative abundance and distribution of birds at Nensebo forest in southern Ethiopia. Methods: We employed a stratified random sampling technique with our study area stratified into two dominant habitat types: moist Afromontane forest and modified habitat. Within strata, we established 20 transect lines of 1km length and 0.25km width to sample 27.75% of the study area. We used line transect count methods aided by binoculars to estimate avian species diversity and distribution. We employed quantitative biodiversity indices, such as Shannon wiener diversity indexes to compare species diversity among habitat types and two way ANOVA to analyze the effect of season and habitat on bird species richness and abundance. Results: A total of 105 bird species consisting of 1 endemic, 8 near endemic, 1 globally threatened and 9 Palearctic migrants were recorded in Nensebo forest. Species richness and abundance varied between habitat types in Nensebo forest with mean species richness greater in modified habitat (mean= 4.70 ±1.65) as compared to moist Afromontane forest habitat (mean= 3.95 ±4.12, F=94.66 P<0.001). Additionally, modified habitat (Shannon diversity index= 4.131) harbored higher diversity of birds as opposed to Afromontane forest habitat (Shannon diversity index=3.79). Conclusion: The Nensebo forest has high avian species diversity including several endemic and endangered species revealing the importance of this site for bird conservation. Although we found that habitat heterogeneity favored bird species diversity, moist Afromontane habitat is critical for forest obligate species. Hence, sustainable bird conservation strategies including land use planning should be initiated for this area.


2013 ◽  
Vol 42 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Reda Iršėnaitė ◽  
Ernestas Kutorga

Wood-inhabiting fungi on pedunculate oak (<em>Quercus robur</em>) coarse woody debris (CWD) was investigated in 50 plots of 0.1 ha in oak stands of different ages in Lithuania. In maturing stands (50-120 years) the average volume of oak CWD was 4.7 m<sup>3</sup>/ha, and in mature stands (over 120 years) – 13.9 m3/ha. Both in maturing and mature stands, the greatest fraction of CWD consisted of fallen oak branches (81 % and 84 % respectively), whereas fallen trunks comprised about 10 % of the total units of CWD. In total 1350 records of 203 species (49 ascomycetes and 154 basidiomycetes) were collected during 2 years of investigation. Species richness and abundance increased significantly with the increase of volume and abundance of CWD. Higher species richness was detected in mature stands than in maturing ones. Wood-inhabiting species composition varied greatly at stand scale, and one third of all detected species occurred only in one plot. Red-listed fungi were found only in mature stands. We conclude that, even in managed oak stands, oak CWD maintains a rather diverse species composition of ascomycetes and basidiomycetes. However, the current practice of forestry in Lithuania of removing dying or dead wood of large volume, e.g. standing and fallen trunks, reduce the distribution of highly specialized, usually rare, and endangered fungi.


Author(s):  
John S. Gray ◽  
Michael Elliott

In the previous chapter we covered ways of describing samples of benthos, but specifically did not include diversity. We can talk of primary community variables, such as abundance (A), species richness (S) and biomass (B), and derived variables from these such as true diversity indices, evenness indices, and ratios indicating the relationship between species richness and abundance (A/S, the abundance ratio or the average abundance per species) and between biomass and abundance (B/A, the biomass ratio or the mean biomass per individual). Diversity is not just simply about the number of species found in a sample or area, but also uses data on the abundances of individuals among the species and the way those abundances are distributed among the species within the assemblage. There are many ways of describing diversity. Here we give a summary of the most important ones and reference sources of recent literature on the subject (see also the data analysis summary in Chapter 11). In the following section we consider simple indices (univariate) as measures of diversity; multivariate methods of analysing patterns will be covered in Chapter 7 on the effects of disturbance. The simplest way to measure diversity is the number of species found in a sample, called the species richness (S or SR). Yet diversity is not just about numbers of species; it is also concerned with the distribution of numbers of individuals per species. For example, if one assemblage has 50 individuals of each of 2 species A and B whereas another assemblage has 99 individuals of species A and 1 individual of species B, then both have the same species richness but the first assemblage is the more diverse. Thus a measure of diversity (an index) must take into account not only the number of species, but also the number of individuals per species. To distinguish this from species richness, the combination of individuals per species and number of species is called heterogeneity diversity. In fact there are a large number of diversity indices, and we do not propose to consider them all here (Magurran 2004 gives an excellent and detailed account and others are mentioned in the summary in Chapter 11).


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 775
Author(s):  
Muhammad Farooq ◽  
Xianfu Li ◽  
Lu Tan ◽  
Davide Fornacca ◽  
Yanpeng Li ◽  
...  

Mountain freshwater ecosystems are threatened all over the world by a range of human-induced stresses, ensuing in a rapid loss of habitats and species diversity. Many macroinvertebrates are reactive to habitat disturbance, and mayflies (Ephemeroptera) are amongst the most sensitive groups. Despite they are susceptible to environmental deviation, knowledge concerning their species richness and diversity is still unknown in remote areas. The objectives of this study were to (1) investigate the mayfly species assemblage and community composition along different mountain streams and assess potential differences, and (2) identify the environmental variation and its influence on the structure of mayfly communities within such freshwater systems. We collected biological and environmental data from 35 sites situated along elevation gradients in the Baima Snow Mountain, northwest Yunnan, China. Multivariate analyses were performed on the environmental variables and the mayfly species composition, as well as on richness and diversity indices. We found that the community composition of mayflies was different across all three watercourses. Among the 18 Ephemeroptera taxa identified, Baetis sp. and Baetiella marginata were highly dominant, accounting for over 50% of the dissimilarity of each stream. In terms of species assemblages, almost all sites in the Yeri stream hosted good-quality habitats for several mayfly species, as reflected by the highest species richness. The Benzilan stream followed, whereas the Sharong stream showed relatively low mayfly assemblage. This variation was explained by the high environmental heterogeneity between the three watercourses. In particular, the RDA model revealed that among the different environmental factors analyzed, altitude, conductivity, total dissolved solids, water temperature, dissolved silicon, and pH explained most of the variation in species composition. Moreover, the altitude alone explained 17.74% of the variation, and in-depth analysis confirmed its significant effect on diversity indices. Further research should focus on evaluating the scale of threats to this important group of insects in the mountain freshwater ecosystem, particularly the impact of human-induced disturbances such as land use/landcover alterations.


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