Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning.
1 December 2018 in Science of The Total Environment
The challenges of a changing climate have directed greater attention to afforestation, but the effects of afforestation on soil fertility and soil biota have not been fully clarified. To explore changes in the soil conditions in two 20-year-old forest plantations established in formerly intensively fertilized plots of agricultural land, we focused on the current developmental state of the sites that received the most fertilizer and evaluated soil properties and Collembola (springtails) communities. Sessile oak (Quercus petraea) and black locust (Robinia pseudoacacia) that had been planted in the afforestation sites were assessed for differences between plantations of native and invasive species. Five adjacent reference associations, including forests and open habitats, were also analyzed and compared. Results showed that the soils in the two afforested sites were similar in their properties and Collembola communities to those of the control cultivated forests, but differed from each other in pH, calcium, phosphorus, and ammonium content. The available potassium and phosphorus contents in the soil of the sessile oak plantation were still high, while the soil organic matter content was adequate (SOM > 2.0%) in both plantations. Species richness of Collembola ranged from 18 in the cultivated arable land to 43 in the relict forest. Only a few species typical for forests (e.g.,Neanura muscorum,Isotomiella minor,Entomobrya muscorum) were detected in the young plantations, while species characteristic of open habitats (e.g.,Protaphorura campata,Lepidocyrtus cyaneus) occurred as well. Although more individuals and species of Collembola were present in the soil of young plantations than in arable fields, their community diversities were significantly lower compared to the control forest stands. Collembola community diversity differed significantly also between the two plantation types (with native and non-native tree species). Mean abundance in the afforested sites was about 2.5 times higher than in the cultivated arable land, yet far lower than the mean abundance in the control forests.
Two new species of the genus Pseudosinella Schaffer, 1897 from Hungary are described and illustrated. Characters shared by both species are the number of eyes (0+0), the labial chaetotaxy (M(1)M(2)rEL(1)L(2)) and the chaetotaxy of abdominal segment II (pABq(1)q(2)). P. csafordi sp. nov., characterized by dorsal macrochaetae formula R0R1R2R3TP/32/0201+2s, inhabits alluvial forests, while P. dungeri sp. nov., characterized by dorsal macrochaetae formula R0R1sR1R2TP/10/0201+2, was collected from a mid-montain steppic grassland.
Increasing human activity is altering the structure of forests, which affects the composition of communities, including birds. However, little is known about the key forest structure variables that determine the richness of bird communities in European temperate oak forests. We, therefore, aimed to identify key variables in these habitats that could contribute to the design of management strategies for forest conservation by surveying 11 oak-dominated forest sites throughout the mid-mountain range of Hungary at 86 survey points to reveal the role of different compositional and structural variables for forest stands that influence the breeding bird assemblages in the forests at the functional group and individual species levels. Based on decision tree modelling, our results showed that the density of trees larger than 30 cm DBH was an overall important variable, indicating that large-diameter trees were essential to provide diverse bird communities. The total abundance of birds, the foliage-gleaners, primary and secondary cavity nesters, residents, and five specific bird species were related to the density of high trunk diameter trees. The abundance of shrub nesters was negatively influenced by a high density of trees over 10 cm DBH. The density of the shrub layer positively affected total bird abundance and the abundance of foliage gleaners, secondary cavity nesters and residents. Analysis of the co-dominant tree species showed that the presence of linden, beech, and hornbeam was important in influencing the abundance of various bird species, e.g., Eurasian Treecreeper (Certhia familiaris), Marsh Tit (Poecile palustris) and Wood Warbler (Phylloscopus sibilatrix). Our results indicated that large trees, high tree diversity, and dense shrub layer were essential for forest bird communities and are critical targets for protection to maintain diverse and abundant bird communities in oak-dominated forest habitats.