Research Article |
Corresponding author: Ondřej Horňák ( hornak.o@seznam.cz ) Academic editor: László Dányi
© 2020 Ondřej Horňák, Andrej Mock, Bořivoj Šarapatka, Ivan Hadrián Tuf.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Horňák O, Mock A, Šarapatka B, Tuf IH (2020) Character of woodland fragments affects distribution of myriapod assemblages in agricultural landscape. In: Korsós Z, Dányi L (Eds) Proceedings of the 18th International Congress of Myriapodology, Budapest, Hungary. ZooKeys 930: 139-151. https://doi.org/10.3897/zookeys.930.48586
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Fragments of woodland fulfil many irreplaceable functions in the agricultural landscape including being the main source of biodiversity of soil invertebrates. Due to intensive farming and land use changes, especially in the second half of the 20th century, fragments of woodland in agricultural landscape almost disappeared. This has led to a decrease in the diversity of invertebrates, especially those for which the presence of these woodland habitats in the landscape is a key element for survival. The aim of this study was to evaluate the importance of fragments of woodland (characterised by their area, vegetation structure, the amount of leaf litter layer and soil moisture) on the distribution of centipedes and millipedes (Myriapoda) in the agricultural landscape of South Moravia (Czech Republic). Myriapods were collected using pitfall traps during summer in 2016 and 2017. Results showed that activity-density of myriapods is positively correlated with thickness of the leaf litter layer. Moreover, the species richness of centipedes is positively correlated with increasing size of fragments of woodland although higher centipedes’ activity-density was found in rather uniform woodlands in term of diversity of tree species.
activity-density, area, Chilopoda, Diplopoda, landscape elements, species richness
Hedgerows, wood fragments, windbreaks, and other wood elements represent an integral part of the agricultural landscape, defined as a mosaic of fields and uncultivated natural or semi-natural areas (
The presence of invertebrates is very important as they provide many irreplaceable ecosystem services. One of the major groups of ground dwelling invertebrates in this regard are myriapods (Myriapoda). Millipedes (Diplopoda) are in most cases detritovores, saprophages or phytophages (
For ground dwelling invertebrates, that use uncultivated areas, hedgerows and fragments of woodland are indispensable as they provide suitable habitats for the survival of their populations in the agricultural landscape (
Fragments of woodland and hedgerows were for centuries under the influence of transformations by farmers, who often evaluated them as being worthless and thus they eliminated them (
Such long-term landscape management caused many negative effects, which also manifested themselves in the ground dwelling invertebrates.
Quality natural resources and ecosystem services that directly provide fragments of woodland and hedgerows or invertebrates, which are supported through presence of these habitats, are indispensable for agriculture. Their rational use and proper management in the landscape should therefore be given special attention (
Research was realized in agricultural landscape of Southern Moravia in the vicinity of the villages of Šardice (48°58'N, 17°2'E), Stavěšice (49°0'N, 17°2'E), Čejč (48°57'N, 16°58'E), and Hovorany (48°57'N, 17°0'E). The studied sites consisted of 38 pre-selected isolated wood fragments and hedgerows. The surrounding matrix of these habitats consisted mainly of arable land, vineyards and partly permanent or temporary grasslands.
Wood fragments represented the remains of lowland broadleaf forests, coastal tree vegetation around the streams, or artificially planted orchards, or wood linear elements forming the natural boundaries between lands. Many patches were largely invaded by self-seeding black locust (Robinia pseudacacia), blackthorn (Prunus spinosa) and elderberry (Sambucus nigra). Remains of large wood stands were mostly made up of linden (Tilia spp.), birch (Betula pendula), ash (Fraxinus excelsior), pine (Pinus silvestris), chestnut (Aesculus hippocastanum), oak (Quercus spp.) or maple (Acer spp.). Other hedgerows were often made of walnut (Juglans regia), cherry (Prunus spp.) or poplar (Populus spp.).
Five pitfall traps were placed at each site, these consisting of a plastic cup of a volume of 3 decilitres (diameter 7 cm, high 13 cm) buried uniformly with the soil surface. The traps were half filled with 4% formaldehyde as a fixative solution and were covered by metal sheets. The pitfall traps were arranged in line spacing 10 m inside a wood patch. Some linear wood strips were only ca 10 m wide; in this situation a line of traps passing through the middle of the strip. In larger patches, the line was placed at least 10 m far from the edge. Traps were installed on the sites for three weeks during June to August of 2016 or 2017. Caught centipedes and millipedes were identified to species level.
The distribution of invertebrates in the landscape was assessed in relation to several selected environmental variables:
(1) size of the sites, which ranged from 0.04 to 7 ha (measured using Google Earth software),
(2) density of the canopy of trees, evaluated at scale 1–4, when level 1 is for canopies covering sky from 0–25%, level 2 for sky covered by canopies at level 26–50%, level 3 for covering sky at level 51–75% and level 4 for canopy covering sky by 76–100%, covering was mean of estimations by naked eyes of three independent persons,
(3) the percentage coverage of surface by herb layer, estimated as mean of three independent estimations (rounded to tens of percent),
(4) dominance of grasses in herb layer, evaluated by the same methods as previous parameter,
(5) thickness of leaf litter layer, measured in centimetres as the mean of three measures on different points at each site,
(6) soil moisture, measured gravimetrically during installation of traps,
(7) species richness of trees, expressed as number of tree species creating evaluated wood fragment and
(8) black locust dominance in tree layer, estimated as the mean of three independent estimations with 10% accuracy.
Constrained ordination and canonical correspondence analysis (CCA) were used to analyse the activity-density and species richness of the invertebrates (dependent variables) in relation to individual environmental factors (independent variables). To assess the trends of the ordination diagrams, we used a generalized additive model (GAM). All analyses were performed using the CANOCO 5 program (
Altogether 245 individuals of centipedes (Chilopoda) in 11 species were caught, and 304 individuals of millipedes (Diplopoda) in 7 species (Tab.
List of the centipedes and millipedes caught on 38 studied localities, total number of individuals caught by 5 traps during 3 weeks and number of localities, at which species was recorded.
Taxon | Individuals | Localities |
---|---|---|
Chilopoda | 245 | 37 |
Geophilus electricus (Linnaeus, 1758) | 3 | 3 |
Lamyctes emarginatus Newport, 1844 | 3 | 3 |
Lithobius aeruginosus L.Koch, 1862 | 2 | 2 |
Lithobius austriacus Verhoeff, 1937 | 1 | 1 |
Lithobius crassipes L.Koch, 1862 | 2 | 2 |
Lithobius cyrtopus Latzel,1880 | 1 | 1 |
Lithobius erythrocephalus C.L.Koch, 1847 | 8 | 6 |
Lithobius forficatus Linnaeus, 1758 | 164 | 32 |
Lithobius micropodus (Matic, 1980) | 2 | 2 |
Lithobius microps Meinert, 1868 | 45 | 18 |
Lithobius mutabilis L.Koch, 1862 | 14 | 9 |
Diplopoda | 304 | 24 |
Blaniulus guttulatus (Fabricius, 1798) | 1 | 1 |
Brachyiulus bagnalli (Curtis, 1845) | 1 | 1 |
Brachyiulus lusitanus Verhoeff, 1898 | 1 | 1 |
Cylindroiulus boleti (C.L. Koch, 1847) | 1 | 1 |
Enantiulus nanus (Latzel, 1884) | 1 | 1 |
Polydesmus cf. denticulatus C.L. Koch, 1847 | 6 | 3 |
Polydesmus complanatus (Linnaeus, 1761) | 293 | 22 |
Using canonical correspondence analysis (CCA) and subsequent generalized additive models (GAM), we tested the species richness and activity-density of both myriapods in total, and centipedes and millipedes independently in relation to individual measured environmental characteristics.
In independent evaluation of centipedes’ distribution, the measured environmental variables explained 22.2% of the pattern of distribution. From the tested environmental characteristics, the size of fragments of woodland (F = 3.8, p = 0.031), the thickness of the leaf litter (F = 3.4, p = 0.045) and species richness of the tree floor (F = 3.6, p = 0.038) proved to be significant (Tab.
The effect of measured environmental factors to myriapod communities. Effects to its activity-density and species richness for both taxa are presented independently.
Chilopoda | Diplopoda | |||||||
---|---|---|---|---|---|---|---|---|
Activity-density | Species richness | Activity-density | Species richness | |||||
F | p | F | p | F | p | F | p | |
area of wood fragment | 1.60 | 0.208 | 3.80 | 0.031 | 1.40 | 0.257 | 2.40 | 0.104 |
canopy coverage | 0.07 | 0.931 | 0.45 | 0.643 | 2.40 | 0.105 | 2.50 | 0.101 |
herb layer coverage | 1.40 | 0.257 | 0.60 | 0.556 | 0.38 | 0.687 | 1.50 | 0.248 |
grasses dominance | 2.10 | 0.144 | 1.50 | 0.237 | 1.50 | 0.229 | 0.69 | 0.506 |
leaf litter thickness | 3.40 | 0.045 | 1.10 | 0.336 | 4.20 | 0.023 | 0.56 | 0.576 |
soil moisture | 0.91 | 0.588 | 2.30 | 0.113 | 0.44 | 0.650 | 0.42 | 0.659 |
tree diversity | 3.60 | 0.038 | 2.90 | 0.071 | 1.10 | 0.341 | 1.20 | 0.326 |
black locust dominance | 0.63 | 0.538 | 1.10 | 0.343 | 2.50 | 0.095 | 0.62 | 0.543 |
In independent analysis of millipedes’ distribution, the measured variables explained 23.5% of variability in their distribution pattern. A significant response of millipedes was to leaf litter thickness (F = 4.2, p = 0.023) in terms of their activity-density, i.e., with increasing thickness of leaf litter the number of captured individuals increased (Fig.
GAM plots evaluating effect of selected measured environmental factors to communities of centipedes and millipedes a relationship between size of wood fragments and number of centipedes’ species trapped b relationship between thickness of leaf litter and number of centipedes trapped c relationship between species richness of trees in sites and number of centipedes trapped d relationship between thickness of leaf litter and number of millipedes trapped. Circles on diagram represent individual fragments of woodland.
We studied the distribution of millipedes and centipedes inhabiting fragments of woodland and hedgerows in intensively used agricultural landscape. We focused on several characteristics of the environment, which, as we supposed, could affect the species richness and abundance of these myriapods. Leaf litter thickness, area size and species richness of tree species affected myriapod assemblages.
Although number of trapped individuals seems to be rather low, very similar number of trapped centipedes (0.45 per trap per week) and millipedes (0.52 respectively) were recorded in hedgerows in Slovakia (
Myriapods usually occur in the leaf litter layer, typically in deciduous forests and benefit from its greater thickness and soil surface coverage. For millipedes, leaf litter is a direct source of food, while centipedes are affected indirectly through the availability of prey (
Millipedes are influenced by the quality of leaf litter consumed, while higher tree species diversity often contributes to greater variability in food supply (
Centipedes showed that with increasing richness of tree species their activity-density decreased. At the same time, in habitats with a lower number (2–4) of tree species black locust dominated. Similarly,
The increase in species richness with area size is mostly attributed to increasing environmental heterogeneity (
Accordingly,
None of the other environmental characteristics investigated has been shown to be significant, although, for example, moisture is one of the major factors affecting the distribution of myriapods, as reported by many authors (
However, there were no substantial differences in moisture within the sites (moisture of soil ranged from 10 to 41% as measured during installation of traps), which may be one of the reasons why moisture did not significantly affect myriapod distribution (
The results of our study show that the leaf litter layer may be one of the important characteristics affecting the surface dwelling myriapod assemblages inhabiting the fragments of woodland in the agricultural landscape. In addition, the size of individual fragments of woodland and the species richness of the tree canopy also have a noticeable effect. These habitat characteristics work together with many other factors, and the interpretation of particular conclusions is often difficult. However, we believe that specific environmental conditions of fragments of woodland are a key element for distribution of myriapod assemblages in intensively cultivated agricultural landscape.
Research was done with the support of a grant from the Ministry of Agriculture, No. QJ1630422 Soil protection using optimization of spatial and functional parameters of landscape structure patterns and an internal grant from the Faculty of Science of Palacký University Olomouc, No. PrF_2019_021. The authors are grateful to László Dányi, Ivan Kos and Jolanta Wytwer for their useful comments that improved quality of our paper and to Gregory D. Edgecombe who improved manuscript linguistically.