Effects of Timing of Grazing on Arthropod Communities in Semi-Natural Grasslands

Abstract

Arthropod communities were investigated in two Swedish semi-natural grasslands, each subject to two types of grazing regime: conventional grazing from May to September (continuous grazing) and traditional late management from mid-July (late grazing). Pitfall traps were used to investigate abundance of carabids, spiders, and ants over the grazing season. Ant abundance was also measured by mapping nest density during three successive years. Small spiders, carabids and ants (Myrmica spp.) were more abundant in continuous grazing than in late grazing while larger spiders, carabids, and ants (Formica spp.) were more abundant in late grazing. The overall abundance of carabids was higher in continuous grazing in the early summer but higher in late grazing in the late summer. The switch of preference from continuous to late grazing coincided with the time for larvae hibernating species replacing adult hibernating. We discuss possible explanations for the observed responses in terms of effects of grazing season on a number of habitat variables for example temperature, food resources, structure of vegetation, litter layer, competition, and disturbance.

Influence of Ecological and Integrated Management of Farming on Biodiversity of Basic Epigeic Group

“…Despite their lower representation, these groups contribute to biodiversity of agroecosystem and reflect its stability. A similar view was also expressed by Lenoir and Lennartsson (2010) who report the epigeic groups with the higher abundance in agroecosystem of Araneida, Formicoidea and Coleoptera, which according to Peterková (2004) due to th high abundance and diversity significantly affect the maintenance of the natural balance and substance cycle and flow of energy in ecosystems. Holecová et al (2003) state that the dominant groups are epigeic ant communities which significantly affect each biocenosis.…”

Effects of large herbivores on grassland arthropod diversity

“…In addition, the life cycle of many arthropod species is strictly synchronized (Zaslavski, 1988). This means that the habitat conditions for each life-cycle stage must be present at exactly the right time of year, making arthropods especially sensitive to the timing of grazing (Carvell, 2002; Lenoir & Lennartsson, 2010; Van Noordwijk et al , a 2012)…”

“…In addition, the life cycle of many arthropod species is strictly synchronized (Zaslavski, 1988). This means that the habitat conditions for each life-cycle stage must be present at exactly the right time of year, making arthropods especially sensitive to the timing of grazing (Carvell, 2002;Lenoir & Lennartsson, 2010;Van Noordwijk et al, 2012a) Third, plants are more plastic in their response to grazing than are arthropods. Plants can often survive (periodical) high trampling and defoliation through dwarf growth, vegetative spread and belowground storage of resources.…”

Biodiversity And Dynamics Of Occurence Of Epigeic Groups In Different Types Of Farming

“…The above findings confirm the view of Kromp and Steinber (1992), who considered epigeic groups Coleoptera, Collembola, Acarina and Araneida for groups typically dominant in agricoenose, but also greatly threatened due to intensive cultivation. Lenoir and Lennartsson (2010) found that excluding mentioned groups, Formicoidea had dominant occurrence in the agricoenose, but this is not confirmed. All groups in their opinion due to its high abundance and diversity significantly affect the maintenance of the natural balance and substance cycles and energy flow in ecosystems.…”

“…L.- Bartošová et al (2005) and Porhajašová et al (2008) claim in their works that the ecological stability of the landscape as a rule increases with increasing the ecosystem and species diversity. Paoletti (1999) under the term epigeon biodiversity explains that among insect (Insecta) living in the soil and on its surface, we can find representatives of many groups, for example species of orders Heteroptera, Neuroptera, Diptera, Larvae, but especially species of order Coleoptera, according to Lenoir and Lennartsson (2010) these are groups typical for agroecosystems. Strašiov et al (2012) paid attention to the occurrence of chilopodecenosis in terms of conservation of biodiversity of their communities in agricultural land, and found out that the application of various forms of management and variety spatial distribution of small-scale agricultural areas positively affect their biodiversity.…”