THE STUDY OF THE IMPACT OF TWO ECOLOGICAL GROUPS OF EARTHWORMS ON PALM AND OLIVE WASTES IN SAHARAN CONDITIONS

2019 ◽  
Vol 75 (1) ◽  
Author(s):  
Kemassi Samia ◽  
Daddi Bouhoun Mustapha
Keyword(s):  
2018 ◽  
Vol 1 ◽  
Author(s):  
Natália Raschmanová ◽  
Vladimír Šustr ◽  
Ľubomír Kováč ◽  
Andrea Parimuchová ◽  
Miloslav Devetter

We hypothesized that trogloxenes inhabiting surface habitats, thermally fluctuating environment, would tolerate wide temperature ranges. We expected that the temperature tolerances would diminish over categories trogloxene - subtroglophile - eutroglophile - troglobiont as a result of the degree of adaptation to subterranean environment that is characteristic with thermally stable conditions. We also assumed that body size may play crucial role in tolerance of Collembola to high and low temperature. Eighteen species of all four categories were exposed to one-hour survival laboratory test. The impact of temperature, species and species-temperature interaction on the cold and heat survival was statistically significant. The species heat tolerance significantly increased with increasing cold tolerance. In general, decrease in cold and heat tolerance was shown from trogloxenes, over subtroglophiles and eutroglophiles to troglobionts. Cryptic species Folsomia sp. among trogloxenes and Ceratophysella sigillata, Hypogastrura crassaegranulata among subtroglophiles were highly heat- and also cold-resistant, showing wide ecological plasticity. Subtroglophilous Tetrodontophora bielanensis and Lepidocyrtus violaceus , eutroglophilous Heteromurus nitidus and troglobiont Protaphorura janosik were the most cold-sensitive species, and all troglobionts and eutroglophilous Pygmarrhopalites pygmaeus as the most heat-sensitive species. Species belonging to ecological groups not or less associated to cave environment (trogloxenes and subtroglophiles) showed wider range of temperature tolerance in comparison with more cave adapted species (eutroglophiles and troglobionts), tested by ANOVA. Cold resistance decreased significantly with increasing body length, indicating that body size plays an important role in temperature tolerances of arthropods inhabiting soil and subterranean habitats.


2020 ◽  
Vol 153 (1) ◽  
pp. 22-32
Author(s):  
Komla Elikplim Abotsi ◽  
Kouami Kokou ◽  
Germinal Rouhan ◽  
Vincent Deblauwe

Contexte et objectifs – La conservation durable de la biodiversité requiert une bonne compréhension des causes de son déclin. Mis à part les activités humaines, les changements climatiques se révèlent comme la principale menace qui pèse sur la biodiversité au 21ème siècle. Notre étude vise à déterminer l’impact du changement climatique sur les Ptéridophytes au Togo.Méthodologie – En se basant sur 2865 occurrences de Ptéridophytes couvrant toute l’Afrique de l’Ouest et regroupés en 5 groupes écologiques, les distributions actuelle et future des Ptéridophytes ont été modélisées grâce à Maxent. La capacité de conservation des aires protégées du Togo vis-à-vis de ces plantes a été évaluée.Résultats clés – Nos résultats montrent que 9,81% du pays peut abriter simultanément l’ensemble des groupes de ptéridophytes. Les précipitations des périodes sèches, l’isothermalité et la saisonnalité de la température sont les variables climatiques qui contraignent le plus leurs niches en Afrique de l’Ouest et particulièrement au Togo. Exceptés les taxons thermophiles dont les zones climatiquement favorables devraient quasiment doubler à l’horizon 2070, les niches des autres groupes devraient se restreindre drastiquement au Togo. Seules les aires protégées du tiers sud des Monts Togo pourront garantir la conservation des niches climatiques actuelles et futures des ptéridophytes dans le pays.Conclusions – Le sud des Monts Togo constituera probablement un refuge climatique pour les ptéridophytes au Togo. Toutefois, la faiblesse de l’étendue des aires protégées dans cette partie du pays pourrait constituer une source de vulnérabilité pour ces plantes.   Vulnerability of pteridophytes to climate change and implications for their conservation in Togo (west Africa)   Background and aims – The sustainable conservation of biodiversity requires a good understanding of the causes of its decline. Apart from human activities, climate change is the major threat to global biodiversity during the 21st century. Our study aims to determine the impact of climate change on pteridophytes in Togo.Methods – Based on 2865 occurrences of pteridophytes covering West Africa and grouped into 5 ecological groups, current and future distributions of pteridophytes were modelized using Maxent. The conservation capacity of Togolese protected areas for these plants was assessed.Key results – Our results show that 9.81% of the country can shelter simultaneously all groups of pteridophytes. Precipitations of the driest periods, isothermality and temperature seasonality are the climatic variables which constrain the most their niche in West Africa and particularly in Togo. Apart from thermophilic taxa whose climatically suitable niche is expected to nearly double by 2070, niche of all other group should be drastically restricted in Togo. Only protected areas in the southern third of Togo Mountains would guarantee current and future climatic niches for pteridophytes in the country.Conclusions – Southern Togo Mountains will probably constitute a climatic refugium for Pteridophytes in Togo. However, the small extent of protected areas in this part of the country would be a source of vulnerability for these plants.


2021 ◽  
Vol 1 (4) ◽  
pp. 1-15
Author(s):  
A.P. Geraskina ◽  

To date, forest ecology has not made any clear conclusions regarding the impact of large saprophagous invertebrates such as earthworms on soil carbon dynamics. Some authors claim that earthworm activities result in decreased carbon accumulation. Other studies show that earthworms contribute to soil carbon accumulation. At the same time, many studies do not take into account the differences between trophic and digging activity of different morpho-ecological groups of earthworms in different soil horizons. The objective of this study was to carry out differentiated assessment of the impact of different morpho-ecological groups of earthworms on carbon accumulation and correspondent soil parameters (nitrogen content and С/N ratio) throughout the change in forest succession status. Field operations were performed in the spring and summer of 2016 and 2018 in three regions: Bryansk Oblast (Bryansk Forest reserve), Moscow Oblast (Moskva–Oka plain, Valuyevsky urban forest) and Northwest Caucasus (Krasnodar Krai, Apsheron forestry; Republic of Adygeya, Caucasian Biosphere Reserve). Three main stages of coniferous-broadleaf forest restoration after clear cuttings were identified in each region. Three test plots 50х50 m were allocated for each stage; geobotanical and soil descriptions as well as earthworm registration were carried out on each plot. It was found out that during the change in forest succession status the species composition and the set of morpho-ecological groups of earthworms became more complicated, but there was no successive replacement of any groups with others. Ambiguous effects of different morpho-ecological groups of earthworms on carbon accumulation in forest soils were revealed. Negative correlation was found between the total biomass of earthworms feeding on the soil surface (epigeic, epi-endogeic and anecic species) and litter store. In the humus horizon, the biomass of epi-endogeic species was positively correlated with the content of carbon. C/N ratio and nitrogen content are unidirectionally correlated with the biomass of earthworms in the horizons of their activity: with an increase in the biomass of earthworms of different morpho-ecological groups, the C/N ratio decreases, and the nitrogen content increases.


10.12737/6546 ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 135-138
Author(s):  
Мухитов ◽  
Lenar Mukhitov ◽  
Самуилов ◽  
Feofan Samuilov

The impact of contrasting conditions of water availability on the size of the upper internodes in wheat varieties was studied under the conditions of the Orenburg steppe zone. It was noted, that less drought-resistant varieties formed a short upper internodes. We conducted a mathematical analysis of the relationship of productivity and length of ear-carrying internodes of spring soft wheat varieties of different ecological groups. It was established, that we can observe a gradual increase of grain productivity with increasing the length of the upper internodes in the studied range. As a result, the following varities were selected for inclusion into the hybridization: Logachevka, Tulaykovskaya steppe, Tulaykovskaya 1, Tulaykovskaya Belozernaya, Prokhorovka and Uchitel. They have the optimal settings for the presented feature. Using the selected varieties as parental forms can enhance the efficiency of wheat breeding programs for resistance to drought in the forest-steppe zone of the Southern Urals.


2020 ◽  
Author(s):  
Guillaume Le Mer ◽  
Nicolas Bottinelli ◽  
Marie-France Dignac ◽  
Arnaud Mazurier ◽  
Laurent Caner ◽  
...  

<p>Plant residues are the main precursors of soil organic matter (SOM) and soil macrofauna is an important driver of ecological processes involved in the sequestration of carbon (C) in soils. In particular, earthworms are one of the largest contributors to soil matter formation in most terrestrial ecosystems. In the short term, they may increase the rate of OM turnover by mineralization, fragmentation and stimulation of microbial activity. On the other hand they may reduce OM degradability by forming stable aggregates and organo-mineral complexes protecting C from mineralization for longer time scales. Earthworms are classified in three main ecological groups depending on their behaviors and on their morpho-functional traits. However, their intra- or inter- ecological group effect on C stabilization needs to be investigated.</p><p>In this study, we explored the impact of earthworm diversity (composed of several species belonging to different ecological groups) on the physicochemical properties of casts, related to CO<sub>2</sub> emissions. We hypothesized that C mineralization in casts would be related to the ecological category.</p><p>We studied casts of 6 species (2 anecic species: Lumbricus terrestris & Aporectodea nocturna, 2 endogeic species: Allolobophora icterica & Aporrectodea caliginosa and 2 epigeic species: Lumbricus castaneus & Eisenia fetida) produced in a silty subsoil with addition of plant litter. Casts were incubated for 140 days under similar laboratory conditions. We measured CO<sub>2</sub> mineralization, pH, elemental composition and physical cast organization by X-ray microtomography (resolution of 9.49 µm voxel) at 7, 42, and 140 days.</p><p>Our results showed lower CO<sub>2</sub> mineralization in aggregates produced without earthworms than all earthworm casts. In the beginning of the incubation casts showed similar CO<sub>2</sub> emissions and specific physicochemical properties as OC content and pH. After 140 days, CO<sub>2</sub> emissions were earthworm species specific with Aporectodea nocturna showing highest CO<sub>2</sub> emissions, and Aporrectodea caliginosa the lowest values. Microtomographic analyses showed that this is due to an increase of cast porosity with increasing cast age coupled with a concurrent decrease particulate organic matter (POM) structures. Our first results seemed to suggest that earthworms belonging to the same ecological category influence similarly C mineralization through their impact on the cast organization.</p>


2016 ◽  
Vol 9 (2) ◽  
pp. 29-60 ◽  
Author(s):  
Ralph Platen ◽  
Thomas Kalettka ◽  
Christian Ulrichs

Abstract Kettle holes are small depressional wetlands and because of the high variability of site factors they are potential hotspots of biodiversity in the monotone arable land. We investigated eight kettle holes and two agrarian reference biotopes for carabid beetles and spiders. The animals were captured with pitfall traps from May to August 2005, along with surveys of the soil and vegetation. We asked whether each kettle hole has specific ecological properties which match with characteristic carabid beetle and spider coenoses and whether they represent isolated biotopes. Differences in the composition of ecological and functional groups of carabid beetles and spiders between the plots were tested with an ANOVA. The impact of the soil variables and vegetation structure on the distribution of species was analyzed with a Redundancy Analysis. The assemblage similarities between the kettle hole plots were calculated by the Wainstein-Index. Ecological groups and habitat preferences of carabid beetles had maximal expressions in seven different kettle holes whereas most of the ecological characteristics of the spiders had maximal expression in only two kettle holes. High assemblage similarity values of carabid beetle coenoses were observed only in a few cases whereas very similar spider coenoses were found between nearly all of the kettle holes. For carabid beetles, kettle holes represent much more isolated habitats than that for spiders. We concluded that kettle holes have specific ecological qualities which match with different ecological properties of carabid beetles and spiders and that isolation effects affect carabid beetles more than spiders.


2020 ◽  
Author(s):  
Maria Ługowska

The paper deals with segetal flora in the Liwiec, Tyśmienica, and Wilga river valleys and with the impact of those locations on biodiversity and migra-tion of species from seminatural communities to arable fields. The studies were conducted between 2014 and 2018 on cereals, root crops, and stubble fields.To this end, the following research objectives were designated: 1. Inventory of flora in the agrocoenoses of the Liwiec, Tyśmienica, and Wilga river valleys. 2. Multidimensional comparative analysis of inventoried vascular plants, including: species occurrence, their geographical and historical origin, life-form, plant propagation, and type of ecological strategy. 3. Assessment of habitat conditions in designated permanent research plots in the transects located in the river valleys. 4. Statistical comparative analysis of habitat conditions in river valleys and permanent research plots. 5. Analysis of flora in permanent research plots in terms of plant sociolog-ical and ecological groups and their development strategies. 6. Statistical assessment of biodiversity in permanent research plots. 7. Analysis of the floristic richness of plant communities in terms of habitat conditions of the valleys of the Liwiec, Tyśmienica and Wilga rivers.


2021 ◽  
Author(s):  
Bibiana Betancur Corredor ◽  
Birgit Lang ◽  
David Russell

<p>The impact of agricultural activities on soil fauna can be highly variable, depending on the management options adopted. High-input agricultural practices can promote a reduction in diversity of soil microarthropod communities but, at the same time can also favor bacterial-feeding fauna through the increase of bacterial food web pathways. In contrast, low-input practices can increase the dominance of fungal-feeding fauna through the promotion of fungal pathways. Responses also vary with time after fertilizer application and are strongly dependent on crop species or shifts in plant species composition due to fertilization. The type of fertilizer, organic or inorganic, can also have diverse effects on soil organisms. Organic fertilizers can increase the population of soil decomposers serving as nutrient sources for other soil organisms. Nitrogen fertilization may disturb soil organisms in a manner that affects ecosystem functioning, but the links are not yet well quantified. Therefore, a systematic compilation of available experimental data on the effects of nitrogen fertilization on taxonomic and functional groups of soil fauna is needed to clarify the patterns and mechanisms of responses. </p><p>Paired observations for meta-analysis were collected from 198 studies published in the last 30 years across 37 countries. First results show that nitrogen fertilization increased the biomass of earthworms (mean increase of 19.7%), the abundance of nematodes (mean increase of 36.6%), springtails (mean increase of 29.7%), and mites (mean increase of 35.2%), and reduced the abundance of earthworms (mean reduction of 9.2%) compared to when no fertilizer was applied. The population responses of all organisms were larger when organic fertilizers were applied. The meta-analyses for different earthworm ecological groups showed that the biomass of epigeic and endogeic earthworms were most sensitive to organic fertilization, and this effect was magnified when higher rates of nitrogen are applied. The meta-analyses for different nematode feeding groups, life-form groups of springtails and mite suborders showed that each group is affected differently by organic and inorganic fertilization. Additional meta-analysis also showed that the responses of the soil organisms to nitrogen fertilization can also be modulated by physicochemical properties of the soil as well as climatic conditions. </p>


2020 ◽  
Vol 28 (2) ◽  
pp. 195-202
Author(s):  
O. M. Kunakh ◽  
I. O. Fedyay

The Heteroptera is a group of animals associated with the vegetation cover. The conducted analysis indicates that groups of heteropterans in the urban environment have a pattern of reaction to the environmental factors, determined using the phytoindication method. In the study, we considered the following hypotheses: 1) phytoindicational assessments of ecological factors may explain the patterns of variation of the groups of heteropterans; 2) among Heteroptera species, comparatively homogenous ecological groups could be distinguished which are characterized by similar character of response to the effect of certain environmental factors; 3) these groups could be used for bioindication of the conditions of environment in urban ecosystems. Stationary collection of heteropterans was performed during three years from May to October of 2017–2019 on six plots in Kharkiv. The article describes factors which affect the structure of groups of Heteroptera within the ecosystem of the large city and assess the bioindication possibilities. The data presented in the article, as well as the conclusions drawn, are to a large extent associated with stenotopic species, most of which could be used as bioindicators of the condition of one or another biocenosis. According to the results of a taxonomical survey in the territory of Kharkiv, 180 species of Heteroptera were found, belonging to 120 genera and 17 families. The highest species diversity was seen for the family Miridae, accounting for 50 species (27.0% of the total number of counted species). Fewer species were identified as the representatives of families Lygaeidae – 46 species (24.9%) and Pentatomidae – 23 (12.4%). Family Rhopalidae was represented by 11 species (5.9%). Nabidae and Tingidae – 10 species each (5.4%). Families Coreidae – 8 (4.3%), Cydnidae and Scutelleridae – 4 species each (2.2%), Anthocoridae – 3 (1.6%). The families Berytidae, Piesmatidae, Pyrrhocoridae and Reduviidae were represented by only 2 species each (1.1%). Families Acanthosomatidae, Alydidae and Aradidae were represented by 1 species each, in total accounting for 1.5%. The reasonably high level of species and ecological diversities of Heteroptera in the territory of the city allows them to be used in bioindication studies. We determined comparatively homogenous ecological groups of heteropterans which have a similar pattern of response to the impact of certain environmental factors. The study demonstrates that phytoindicatory assessments of the ecological factors can explain the patterns of variation in groups of heteropterans, We determined the factors which have effects on the structure of the group of heteropterans within the metropolitan ecosystem. The level of their effect on groups of heteropterans within the city is different. The most influential were light and humidity. Comparison of potential and realized projections of ecological space allows us, to a certain extent, to generate hypotheses about the orientations of transformation of the group heteropterans.


2009 ◽  
Vol 39 (7) ◽  
pp. 1375-1386 ◽  
Author(s):  
Tine Grebenc ◽  
Morten Christensen ◽  
Urša Vilhar ◽  
Matjaž Čater ◽  
María P. Martín ◽  
...  

Data on the impact of forest management practices on ectomycorrhizal community structure remains fragmentary and mainly originates from studies in northern coniferous forests. This study focuses on a comparison of ectomycorrhizal communities between canopy gaps and closed canopy areas within natural and managed beech-dominated forests at four locations in Europe. We used high resolution rDNA techniques to identify ectomycorrhiza-forming fungi and attempted to extract potential stand-, gap-, soil-, and selected environmentally derived variables by applying multivariate analysis and ordination for pooling of ecological groups of ectomycorrhiza. A significant reduction of diversity indices, ectomycorrhizal and fine root dynamics, in gaps in comparison with closed canopy stands indicates an effect of forest management practice and the high importance of maintaining and protecting natural forest areas for conservation of soil biodiversity and forest genetic resources. The ordination analysis revealed three groups of ectomycorrhiza correlated with changing environmental conditions. The litter and soil pH, number of beech seedlings, and presence of a gap had a pronounced effect on the ectomycorrhizal community. Combined analysis of ectomycorrhiza and environmental factors using correspondence analysis provided an insight into the ecological preferences of the analysed species and confirmed that environmental factors drive ectomycorrhizal community changes.


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