Investigations on soil nematode diversity in three contrasting habitat types in Bolu, Turkey (original) (raw)
Related papers
Biological indicative assessment of nematodes in evaluating different terrestrial habitats
International Journal of Agricultural and Applied Sciences
Healthy soil ecosystem plays crucial role maintaining global biosphere and developing sustainable agricultural practices. Land exploitation and improper agricultural practices greatly impact the soil health quality in time and space. Understanding the effects of organic and inorganic enrichments on soil quality and its indicators has been identified as one of the most important goals for modern soil science. For the present study, we compared the differences in the nematode diversity of healthy undisturbed soil with soil enriched with organic amendments and inorganic amendments. Soil samples were collected from three different habitats viz., organic enriched soil, inorganic enriched soil and undisturbed soil in rural and urban areas. Nematode community structure was studied in terms of frequency, density, biomass, trophic diversity and other common diversity or ecological indices. A total of 56, 61 and 72 nematode genera/species were identified in organic enriched, inorganic enriche...
2023
This work evaluates the diversity, and abundance of nematodes and their use as indicators of soil health in an area strongly influenced by industrial wastes (food, metal and paper industries). The relationships between trophic groups, coloniser-persister scale and nematode community indices as well as nematode indicators of soil elements and the relationships of soil elements with different habitats were investigated. Nematodes were recovered from the soil samples of fifty sites from five different habitats. The trophic groups, colonizer-persister scale, and nematode community indices were analysed and compared. To test the significance of the dataset, bivariate linear regression; several samples repeated measure test of Analysis of Variance (ANOVA) have been performed. The Canonical Correspond Analysis (CCA); Principal Component Analysis (PCA), and clustering of habitats were performed to know the relationships between such variables among different habitats. Bacterial feeders with 15,582 individuals were found to be a highly diverse and most abundant group. The results indicated that the nematode diversity and abundance, trophic groups and coloniser-persister ratio were adversely affected by organically enriched habitats to food, metal and paper industries as compared to natural habitats. The habitats contaminated by industrial wastes were mainly dominated by bacterivores and fungivores of c-p2 class. Few colonizer genera were observed to be cosmopolitan and prevalent in all habitats. However, some genera showed specificity towards a particular set of conditions and were more or less endemic for specific habitats.
Ecosystem type affects interpretation of soil nematode community measures
Applied Soil Ecology, 2005
A better understanding of performance among major ecosystem types is necessary before nematode community indices can be applied at large geographic scales, ranging from regional to global. The objectives of this study were to: (1) determine the inherent variability in soil properties among and within wetland, forest and agricultural ecosystems; (2) compare nematode community composition among and within ecosystem types and report genera detected in wetland soils; (3) determine if community composition or composite indices are able to differentiate type and magnitude of disturbance; (4) identify seasonal responses of nematode communities and indices to disturbance; (5) quantify variance components of nematode community measures at the land resource region (LRR) and ecosystem scale. Nematode communities were extracted from soils in relatively undisturbed and disturbed wetland, forest and agricultural soils in three LRR (coastal plain, piedmont and mountain) in North Carolina (n = 18 sites), seven to eight times per year for 2 years, starting in March 1994 and ending in November 1995. Overall, 48, 44 and 45 nematode families were observed in wetland, forest and agricultural soils, respectively. This inventory totaling 110 genera represents the richest nematode fauna reported from wetlands. After adjusting for soil properties as covariables, nematode maturity index (MI) values were inconsistent among ecosystems in their ability to distinguish levels of disturbance. The magnitude of disturbance was greater between relatively undisturbed and disturbed wetland than forest or agricultural soil. Nematode family composition differentiated levels of disturbance and ecosystems better than community indices, and current efforts indicate that taxonomic resolution at the level of genus is necessary for interpretation of ecosystem function. Deviation between disturbance levels in all ecosystems was greatest in July. For use in large-scale environmental monitoring programs, it is more cost-effective and easier to calibrate and interpret indices if variance is greatest at larger rather than at smaller spatial scales, e.g., variance is progressively smaller from among regions, among ecosystems and disturbance within ecosystems. This preferred order of ranking of variance by spatial scale occurred for nematode community indices MI, MI25, SMI25, and SI and abundance of predaceous nematodes. Variance was greater at smaller than at larger spatial scales for nematode community www.elsevier.com/locate/apsoil Applied Soil Ecology 30 (2005) 47-64
Applied Soil Ecology, 2000
The nematode communities of 36 grassland ecosystems in Romania, belonging to different plant associations and soil types, were studied. The abundance of nematodes, the species and trophic types present, as well as their distribution in relation to plant community and soil characteristics are analyzed and discussed. The abundance of nematodes from the 36 grasslands studied ranged between 0.41 × 10 6 and 8.57 × 10 6 individuals/m 2 , and a total of 121 genera and 145 species of nematodes were found. The highest diversity was found in grasslands developed on brown earth soil (65-67 genera and 74-76 species), with least diversity in those evolving on podzol and lithosol (33-36 genera with 25-28 identified species). Most of the dominant taxa were found in specific soil layers; some obligate plant parasitic genera (e.g., Paratylenchus, Rotylenchus, Criconema) showed preference for deeper soil layers. The nematode diversity index (H), with values ranging between 2.38 and 3.47, did not differ significantly between the different types of grasslands. Plant feeding, bacterial feeding, hyphal feeding and omnivorous nematodes were the main groups in mountainous grasslands developed on different soil types. Plant feeding and bacterial feeding nematodes dominated the trophic structure and more plant feeders (62-69%) were found in communities of subalpine and alpine grasslands developed on podzol and alpine meadow soil, than in those developed on rendzina and lithosol (27-33%). The ratio of hyphal feeding to bacterial feeding nematodes (Hf/Bf) is constantly in favour of the bacterial feeding group, the values being an indicator of good soil fertility for most studied grasslands. The nematode communities of grasslands are grouped into six main clusters according to their genera affinity and distinguished by different grassland and soil types. Communities from subalpine grasslands developed on rendzina, acid brown and lithosol have the greatest similarities. An ordination of nematode communities in relation to important environmental variables is presented. Environmental variables relevant in explaining the patterns of nematode composition in grasslands, using canonical correspondence analysis (CCA), are: humus, pH, total nitrogen, exchangeable bases and soil type. No single factor could be selected.
Journal of Applied and Natural Science, 2022
Nematodes are the most numerous soil dwelling organisms comprising the largest phylum in the animal kingdom in relation to diversity and abundance. They have diverse feeding habits and habitats based on which different functional groups of nematodes are developed. The functional characteristics of nematodes reveal ecosystem functioning and soil biodiversity. However, ecological research also indicates that ecosystem functioning is defined by the functional diversity or functional characteristics of organisms (Hooper et al., 2005, McGill et al., 2006). Functional characteristic-based knowledge also reveals the complexity of a community and any disturbance to ecosystems (
Biology and Fertility of Soils, 1992
Nematodes are the most abundant metazoans in soil, and are exceeded in species diversity only by the arthropods. Estimates of nematode diversity in natural and agroecosystems have been based on both species-level taxonomy and trophic-level guilds. Because trophic groups do not act in a unitary manner with respect to environmental alterations, species-level analysis is more meaningful and should be preferred for most kinds of investigations. Nematodes of a biotope have often been considered as mere assemblages, but there is increasing evidence that certain plant associations have characteristic groups of species. This concept has been used by Bongers to develop a maturity index relating nematode families and site stability, and to identify assemblages that colonize disturbed soils. Major constraints on detailed ecological studies of soil nematode faunas are an incomplete understanding of trophic groups and their subsets, the need for repeated sampling of seasonally variable populations, and a severe shortage of taxonomycompetent persons, especially for microbial feeders.
Nematode community structure as indicator of soil functioning in European grassland soils
European Journal of Soil Biology, 2001
This investigation analyses whether soil nematode diversity is correlated with soil functional parameters to serve as bioindicator of soil functioning. The analysis focuses on the interrelations of nematofauna, microflora, and soil nitrogen pools. The sites studied represent six major European grassland types: Northern tundra, atlantic heath, wet grassland, seminatural temperate grassland, East European steppe, and mediterranean garigue. Continental and local climate gradients were combined to a wide and continuous range of microclimate conditions. Nematode richness, as indicated by the number of genera, was highest under temperate conditions and declined towards the climatic extremes. Differences in richness affected all nematode feeding types proportionally. Nematode richness was the only parameter among a range of 15 alternatives tested that exhibited consistent correlations with mass and activity parameters of both nematofauna and microflora in the mineral grassland soils (garigue, wet grassland, seminatural grassland, steppe). In the same soils, the nematode Maturity Index was the best indicator of nitrogen status. We conclude that a high nematode richness can generally be seen as a good indicator of an active nematofauna and microflora in mineral grassland soils, and hence as an indicator of the decomposition function. The prospects of exploiting nematode diversity as an indicator of soil functioning are critically discussed. © 2001 Éditions scientifiques et médicales Elsevier SAS bioindication / diversity-function relationship / microflora / nematodes / soil nitrogen
Ecological Indicators, 2014
Biodiversity surrogates are often used in ecology to save money and time. One such widely used surrogacy method is the higher taxon approach, also known in the literature as taxonomic sufficiency. This approach has rarely been applied to microscopic organisms like soil microfauna, although there is a lack of detailed taxonomic knowledge regarding the latter. We tested taxonomic sufficiency for genus alpha and beta diversity, as well as for community structure of soil nematodes. We also tested whether the functional classifications of nematodes into functional guilds and trophic groups can serve as efficient indicators of nematode diversity and community structure. We used data from soil nematode communities from five different microhabitats (soil, soil moss, rock moss, low tree trunk moss and high tree trunk moss) in forested and non forested areas at five different stations (differing in elevation and aspect). Our results showed that both the higher taxon approach and the functional surrogacy approach could serve as reliable indicators of alpha and beta diversity. Furthermore, our community analysis of both taxonomic and functional composition identified that the variability at the finer scales, and namely the habitat structure, played the leading role in shaping nematode communities.
The use of nematodes in ecological soil classification and assessment concepts
Although there has been extensive applied agricultural research (research on plant-parasitic species has a long tradition), insufficient taxonomical knowledge, especially of free-living nematodes, is a serious problem concerning the use of nematodes in soil classification and assessment. However, due to their essential and various roles in ecosystem functioning and their high diversity and abundance, interest in using these organisms for the assessment of soil quality is increasing. In particular in The Netherlands, but also in other countries (e.g., Germany, United Kingdom), progress in taxonomy is being achieved and evaluation strategies are being elaborated. While examples exist for the successful use of nematodes as part of a community approach comprising several organism groups, much work concerning the establishment of an adequate reference database remains to be done. This article is a general overview of the suitability and application of soil nematodes in soil assessments.
Nematodes for Soil Quality Monitoring: Results from the RMQS BioDiv Programme
Open Journal of Soil Science, 2013
A French programme, "Réseau de mesure de la qualité des sols: biodiversité des organismes" (RMQS BioDiv) was developed in Brittany (27,000 km² in the western part of France) as an initial assessment of soil biodiversity on a regional scale in relation to land use and pedoclimatic parameters. The nematode community assemblages were compared among the land use categories. Crops were characterised by a high abundance of bacterial-feeders, particularly opportunistic bacterial-feeders belonging to Rhabditidae. Meadows presented a higher total abundance of nematodes than did crops (20.6 ind·g −1 dry soil vs. 13.1 ind·g −1 dry soil), and they were mainly linked to the great abundance of plant-parasitic nematodes, particularly Meloidogyne, but with a very high heterogeneity between sampled plots. The nematodes were most abundant in forests (23.7 ind·g −1 dry soil) and presented the most structured community (SI = 82.2 in forests vs. 58.6 and 55.5 in crops and meadows, respectively). Forests had also the higher fungal component (fungal-feeders and facultative plant-feeders belonging to the Tylenchidae) leading to a significant higher part of the fungal decomposition pathway in forests than in crops. The ability of different taxonomic levels of nematode identification to discriminate among different cropping systems (i.e., continuous cropping system, crop with meadow in the rotation, meadow with crop in the rotation and permanent meadow) was also tested. The family level (48 families identified in these samples) was more efficient than the other taxonomic levels (86 taxa, 17 functional guilds and 6 trophic groups): best statistical significant discrimination for time spent in identification. The relation between the nematode ecological indices, the abundance of nematode trophic groups and the crop management practices were studied. The effects of fertilization, ploughing frequency, use of pesticides and management systems on ecological indices, particularly on the Maturity Indices, were observed. Figure 4. Box plot of the nematode parameters in relation to agricultural practices: (a) Management system and the nematode ecological indices MI, BaMI and FuMI; (b) Fertilisers and the nematode ecological indices MI, NCR and EI; (c) Ploughing frequency and the nematode ecological indices MI, PPI and CI; (d) Time since last tillage and the nematode ecological indices MI, PPI and EI; (e) Use of pesticides and the nematode ecological indices MI, NCR and CI (n = 99; forest sites excluded from these analyses).