scholarly journals Composition and functional groups of epiedaphic ants (Hymenoptera: Formicidae) in irrigated agroecosystem and in nonagricultural areas

2009 ◽  
Vol 44 (8) ◽  
pp. 904-910
Author(s):  
Patricia Hernández-Ruiz ◽  
Gabriela Castaño-Meneses ◽  
Zenón Cano-Santana

The objective of this work was to evaluate the species composition and functional groups of ants in nonagricultural (NA) and in irrigated areas (S, seasonal irrigation; P, irrigation with well water; W, irrigation with wastewater) in an arid agricultural region in central Mexico, throughout 2005 and 2006. A total of 52,358 ants belonging to 6 subfamilies, 21 genera and 39 species was collected using pitfall traps. The species best represented in all plots were: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum and Dorymyrmex spp. NA plots recorded the highest density of ants. The highest values for diversity (H') and equitativity (J') were recorded in NA and P plots, while the lowest were recorded in W plots. Cluster analysis showed two different groups regarding species composition: NA-S and W-P. Functional groups recorded were: dominant Dolichoderinae, three species; subordinate Camponotini, five species; hot climate specialists, three species; tropical climate specialists, seven species; cold climate specialists, five species; cryptic species, one species; opportunists, six species; generalized Myrmicinae, nine species. Agricultural activity affects the structure of the ant community with epiedaphic forage, and the constant use of irrigation wastewater in conjunction with intense agricultural practices has negative effect upon species richness of epiedaphic ants.

2014 ◽  
Vol 92 (1) ◽  
pp. 49-55 ◽  
Author(s):  
T.M. Radtke ◽  
J.R.N. Glasier ◽  
S.D. Wilson

Habitat alteration by exotic plant species can have profound effects on vertebrates, but its effects on invertebrates are less well-known. Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a perennial grass that has been planted on >106ha of the Great Plains. We tested the hypothesis that invertebrate communities (especially ants) differed between native grasslands and A. cristatum stands, using pitfall traps in Saskatchewan and Montana. Ant species composition differed significantly between native grasslands and A. cristatum stands, but there were no differences in total ant abundance, the abundance of functional groups, or species richness. Ant species richness was significantly greater in Montana than Saskatchewan. In Saskatchewan, bare ground was positively related to total ant abundance and the abundance of “cold-climate specialist” and “opportunist” functional groups of ants. In Montana, the cover of forbs was positively related to total ant abundance. The abundances of individual ant species were not predicted by any vegetation characteristics, except for Formica obscuripes Forel, 1886, which increased significantly with litter. The total abundance of other invertebrates was greater in native grasslands than in A. cristatum stands, although not significantly so. Within each vegetation type, variation in ant communities may depend either directly on the effects of vegetation species composition, or indirectly via the effect of vegetation on other factors such as temperature. The results suggest that ant community composition was influenced more by variation within grasslands and between locations than by differences between native and exotic grasslands.


Sociobiology ◽  
2021 ◽  
Vol 68 (2) ◽  
pp. 6071
Author(s):  
Roberta De Jesus Santos ◽  
Pavel Dodonov ◽  
Jacques Hubert C. Delabie

Conversion of natural to anthropogenic environments affects biodiversity, and the understanding of these impacts may be improved by assessing how different functional groups respond to such land conversion. We studied land conversion impacts on ant functional groups, as ants are ecologically important and respond well to various environmental changes. We hypothesized that conversion of natural to anthropogenic environments modifies the composition of functional groups, fostering generalist and opportunistic groups over specialist ones, with more responses of this type in tropical than in temperate regions. We recovered 412 papers from ISI Web of Science, of which we selected 17 studies, published between 1993 and 2018, that addressed our study’s question. We assessed whether each functional group responded positively or negatively to conversion of natural habitat into anthropogenic land uses and used Monte Carlo tests to assess significance. Ants were affected by natural habitat conversion into monoculture and polyculture and by the conversion of savannas and of tropical and subtropical forests. Land conversion affected six of the 13 functional groups assessed here. In the temperate zone, cryptic species, predators, subordinate Camponotini, cold-climate specialists and tropical-climate specialists were impaired, whereas hot-climate specialists were favored. In the tropics, land conversion negatively impacted fungus-growers and predators. In both climatic zones, several functional groups, mainly those with broad ecological niches, did not respond to land conversion. Our results corroborate that land conversion effects vary among ant functional groups and indicate that the ant fauna of temperate ecosystems may be more susceptible than that of tropical regions.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 474
Author(s):  
Darija Lemic ◽  
Ivana Pajač Živković ◽  
Marija Posarić ◽  
Renata Bažok

The aim of this study was to determine the effects of different pre-sowing operations on the abundance and composition of total soil fauna in soybean cultivation, with special attention to carabids as biological indicators of agroecosystem quality. The study was conducted in central Croatia with six different pre-sowing activities (cover crop, mulching, ploughing, glyphosate, fertiliser removal, conventional tillage). Pitfall traps were used to collect soil fauna in April, June and September. After determining the abundance and composition of the fauna, their coenological characteristics were calculated and statistical analysis was performed. During the study, 7836 individuals of soil fauna were collected. The composition consisted of 84% beneficial, 8% harmful and 8% indifferent fauna. Class Insecta was the most numerous with a proportion of 56%, with most members of the family Carabidae (1622 individuals), followed by the class Arachnida (40%). The number of fauna collected was influenced by the interaction between pre-seeding intervention and sampling date. Pre-seeding interventions that did not involve soil activities did not affect the number and composition of soil fauna at the beginning of vegetation. Mechanical interventions in the soil and warmer and drier weather have a negative effect on the number and composition of soil fauna. As the season progresses, the influence of pre-sowing activities on soil fauna in soybean crops decreases. It seems that a reduction in mechanical activities in the shallow seed layer of the soil has a positive effect on species richness or diversity. Of particular note is the large proportion of beneficial insects that currently colonise the study area, characterising soil richness and stable natural equilibrium.


2021 ◽  
pp. 1-9
Author(s):  
T.P. Rajesh ◽  
Anjana P. Unni ◽  
U. Prashanth Ballullaya ◽  
K. Manoj ◽  
Palatty Allesh Sinu

Abstract Sacred groves (SGs) of India are islets of forests providing ecosystem and spiritual services to man. Studies suggest that SGs are deteriorating on their quality due to urbanization, invasive species, land-use change, and religious modernization. We explored diversity, community, and abundance of overall and different functional groups of litter ants, including Anoplolepis gracilipes – an invasive ant – on paired SG-neighbouring home garden (HG) sites in rural and urban landscape to (a) assess the quality of SGs and (b) examine whether the variation in ant community of the two habitats was predicted by urbanization and abundance of A. gracilipes. We considered species and local contribution to β-diversity to identify species and sites crucial for conservation of sites. Abundance and richness of overall ants, proportional trap incidence of species, and abundance of A. gracilipes were similar on SG and HG, but species diversity and abundance of certain ant functional groups were higher on SG. Ant community of SG was different from HG, but was not affected by urbanization. A. gracilipes and rural SGs contributed the most to β diversity. A. gracilipes gave little pressure on native ant community. The study concludes that SGs, despite invaded by A. gracilipes, have potential for conserving biodiversity.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ahmad Zia Wahdat ◽  
Michael Gunderson

PurposeThe study investigates whether there is an association between climate types and farm risk attitudes of principal operators.Design/methodology/approachThe study exploits temperature variation in the diverse climate types across the US and defines hot- and cold-climate states. Ordered logit and generalized ordered logit models are used to model principal operators' farm risk attitudes, which are measured on a Likert scale. The study uses two datasets. The first dataset is a 2017 survey of US large commercial producers (LCPs). The second dataset provides a Köppen-Geiger climate classification of the US at a spatial resolution of 5 arcmin for a 25-year period (1986–2010).FindingsThe study finds that principal operators in hot-climate states are 4–5% more likely to have a higher willingness to take farm risk compared to principal operators in cold-climate states.Research limitations/implicationsIt is likely that farm risk mitigation decisions differ between hot- and cold-climate states. For instance, the authors show that corn acres' enrollment in federal crop insurance and computers' usage for farm business are pursued more intensely in cold-climate states than in hot-climate states. A differentiation of farm risk attitude by hot- and cold-climate states may help agribusiness, the government and economists in their farm product offerings, farm risk management programs and agricultural finance models, respectively.Originality/valueBased on Köppen-Geiger climate classification, the study introduces hot- and cold-climate concepts to understand the relationship between climate types and principal operators' farm risk attitudes.


Author(s):  
Sergei L. Esyunin ◽  
◽  
Nadezhda L. Ukhova ◽  
Anna M. Domolazova ◽  
◽  
...  

The assemblages of herpetobion spiders from four habitats: two seven-year-old burns, spruce-birch and fir-spruce forests, were examined in the Visimskiy Reserve (Sverdlovsk Region) during May-September 2017 using pitfall-traps. The structure of the spiders population of burns significantly differs from that of forests in species composition, total occurrence rate (ind./100 trap-days), seasonal dynamics and composi-tion of the dominant species. Differences in the structure of the population are most pronounced in the summer. In summer spider assemblages of burns, the most abundant are Agyneta allosubtilis, Alopecosa pulverulenta, P. fulvipes, P. lugubris, P. riparia and Piratula hygrophila, in forests - Allomengea scopigera and Haplodrassus soerenseni.


2018 ◽  
Vol 10 (9) ◽  
pp. 3153
Author(s):  
Ditmar Kurtz ◽  
Marcus Giese ◽  
Folkard Asch ◽  
Saskia Windisch ◽  
María Goldfarb

High impact grazing (HIG) was proposed as a management option to reduce standing dead biomass in Northern Argentinean (Chaco) rangelands. However, the effects of HIG on grassland diversity and shifts in plant functional groups are largely unknown but essential to assess the sustainability of the impact. During a two-year grazing experiment, HIG was applied every month to analyze the seasonal effects on plant species composition and plant functional groups. The results indicate that irrespective of the season in which HIG was applied, the diversity parameters were not negatively affected. Species richness, the Shannon–Wiener diversity index and the Shannon’s equitability index did not differ from the control site within a 12-month period after HIG. While plant functional groups of dicotyledonous and annual species could not benefit from the HIG disturbance, C3-, C4-monocotyledonous and perennials increased their absolute and relative green cover. Our results suggest that HIG, if not applied in shorter frequencies than a year, neither alters diversity nor shifts the plant species composition of the grassland plant community, but instead it promotes previously established rather competitive species. HIG could therefore contribute as an alternative management practice to the sustainable land use intensification of the “Gran Chaco” grassland ecosystem and even counteract the encroachment of “low value” species.


Author(s):  
Chengxue Ma ◽  
Chang Zhao ◽  
Patteson Chula Mwagona ◽  
Ziyu Li ◽  
Zixuan Liu ◽  
...  

The debates about the extent to which phytoplankton in freshwater ecosystems are regulated by top-down or bottom-up forces have been ongoing for decades. This study examines the effects of bottom-up and top-down factors on the phytoplankton functional groups in a eutrophic lake. Phytoplankton and zooplankton were sampled and physical-chemical variables measured from May 2019 to October 2019 in Lake Hulun, China. Approximately 43 phytoplankton species were observed and grouped into 23 functional groups. For the zooplankton, about 27 species were observed and classified into 8 functional groups. The study revealed that the bottom-up effects of physical-chemical variables on some phytoplankton functional groups was stronger than the top-down effects of zooplankton. Water temperature (WT), total phosphorus (TP), total nitrogen (TN), conductivity (Cond), water transparency (SD), and dissolved oxygen (DO) significant influence the biomass of the phytoplankton functional groups. The biomass of phytoplankton functional groups was influenced positively by nutrient availability likely because nutrients influence the growth and reproduction of phytoplankton in freshwater. WT and DO had a positive influence on biomass of phytoplankton functional groups. Conversely, phytoplankton biomass revealed a decreasing trend when SD and Cond significantly increased. This study showed that zooplankton functional groups were positively correlated with phytoplankton biomass implying that the top-down control of phytoplankton by the zooplankton in the lake is not strong enough to produce a negative effect. It is evident that the zooplankton functional groups in Lake Hulun are controlled more by bottom-up force than top-down.


2019 ◽  
Vol 11 (23) ◽  
pp. 6782 ◽  
Author(s):  
Maria-Mar Fernandez-Antolin ◽  
José-Manuel del-Río ◽  
Roberto-Alonso Gonzalez-Lezcano

In this research work, energy simulation was used as a forecasting tool in architectural design. It includes the study of a multi-family residential building in five different climate zones of Spain, i.e., A4 (very hot climate zones), B4 (hot climate zones), C4 (moderate climate zones), D3 (cold climate zones), and E1 (very cold climate zones). The authors accomplished a sensitivity analysis in order to identify the influence of passive strategies (i.e., with regard to solar reflectance) and renewable energy (i.e., with regard to aerothermal energy) on indoor temperatures and energy demands. The increment in indoor temperatures depends on the neighboring buildings so that effect of urban contexts as a source of protection against sunlight is also considered. The increment in the albedo (i.e., the solar reflectance) of the façade during the winter period produces little differences in indoor operative temperatures. On the contrary, during the summer period, it produces large temperature differences. Therefore, it is shown that colors significantly reduce temperatures from 1.24 to 3.04 °C, which means considerable annual energy savings. This research demonstrates that solar reflectance can reduce the air indoor operative temperature down to 4.16 °C during the month of May in the coldest climate zones. As a result of the simulations, it is noted that the coldest climate zones are influenced to a greater extent by the inclusion of their urban contexts in the simulations. However, the heating demand, without considering it, becomes lower. Therefore, ignoring the urban context produces important errors in the heating analysis (12.2% in the coldest climate zones) and also in the cooling analysis (39% in the hottest climate zones). Finally, the use of renewable energy in the configuration of a model with a high urban canyon (Hc), as well as with an east–west building orientation and a low albedo produces a difference of around 76% in the cooling costs within the hottest climate zones and around 73% in the heating costs within the coldest climate zones. The results of this study can be applied as a guideline in early architectural design.


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