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Density and community structure of soil- and bark-dwelling microarthropods along an altitudinal gradient in a tropical montane rainforest.

Illig J, Norton RA, Scheu S, Maraun M - Exp. Appl. Acarol. (2010)

Bottom Line: However, as we predicted the density of each of the groups decreased with soil depth.Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata.The oribatid mite community on bark did not differ significantly from that in soil.

View Article: PubMed Central - PubMed

Affiliation: Technische Universität Darmstadt, Institut für Zoologie, Schnittspahnstrasse 3, Darmstadt, Germany.

ABSTRACT
Microarthropod communities in the soil and on the bark of trees were investigated along an elevation gradient (1,850, 2,000, 2,150, 2,300 m) in a tropical montane rain forest in southern Ecuador. We hypothesised that the density of microarthropods declines with depth in soil and increases with increasing altitude mainly due to the availability of resources, i.e. organic matter. In addition, we expected bark and soil communities to differ strongly, since the bark of trees is more exposed to harsher factors. In contrast to our hypothesis, the density of major microarthropod groups (Collembola, Oribatida, Gamasina, Uropodina) was generally low and decreased with altitude. However, as we predicted the density of each of the groups decreased with soil depth. Density of microarthropods on tree bark was lower than in soil. Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata. The oribatid mite community on bark did not differ significantly from that in soil. The number of oribatid mite species declined with altitude (24, 23, 17 and 13 species at 1,850, 2,000, 2,150 and 2,300 m, respectively). Rarefaction curves indicate that overall about 50 oribatid mite species are to be expected along the studied altitudinal gradient. Results of this study indicate (1) that microarthropods may be limited by the quality of resources at high altitudes and by the amount of resources at deeper soil layers, and (2) that the bark of trees and the soil are habitats of similar quality for oribatid mites.

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Principal component analysis (PCA) of oribatid mites at four different altitudes (1,850, 2,000, 2,150, 2,300 m) in soil. PCA was carried out with log-transformed data that were calibrated for density. The altitude was included as a passive variable. Eigenvalues of axes one and two were 0.38 and 0.19 respectively
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Fig3: Principal component analysis (PCA) of oribatid mites at four different altitudes (1,850, 2,000, 2,150, 2,300 m) in soil. PCA was carried out with log-transformed data that were calibrated for density. The altitude was included as a passive variable. Eigenvalues of axes one and two were 0.38 and 0.19 respectively

Mentions: The community structure of Oribatida changed along the altitudinal gradient (DFA: Wilks’ Lambda 0.0097; F9,14 = 9.38; P = 0.001), and differed significantly between each of the four altitudes as indicated by Mahalanobis distances (MD). Differences were most pronounced between 2,150 and 2,300 m (MD = 74.11; P = 0.0006), and least pronounced between 1,850 and 2,300 m (MD = 13.37; P = 0.045). PCA with the calibrated densities of Oribatida also showed that the community structure did not gradually change from the lower to the higher altitudes; rather the community structure of Oribatida at lower altitudes was similar to that at the highest altitude (Fig. 3). Galumnidae dominated at 1,850 m, parthenogenetic taxa such as (most) Suctobelbidae, Oppiella nova and Rostrozetes sp. were dominant at 2,000 m; Rhynchoribates ecuadoriensis, Epidamaeus sp. and Brachyoppiella periculosa had their highest relative densities at 2,150 m, whereas the parthenogenetic species Malaconothrus angulatus was the only Oribatida species that had its highest relative abundance at 2,300 m (Fig. 3).Fig. 3


Density and community structure of soil- and bark-dwelling microarthropods along an altitudinal gradient in a tropical montane rainforest.

Illig J, Norton RA, Scheu S, Maraun M - Exp. Appl. Acarol. (2010)

Principal component analysis (PCA) of oribatid mites at four different altitudes (1,850, 2,000, 2,150, 2,300 m) in soil. PCA was carried out with log-transformed data that were calibrated for density. The altitude was included as a passive variable. Eigenvalues of axes one and two were 0.38 and 0.19 respectively
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2914295&req=5

Fig3: Principal component analysis (PCA) of oribatid mites at four different altitudes (1,850, 2,000, 2,150, 2,300 m) in soil. PCA was carried out with log-transformed data that were calibrated for density. The altitude was included as a passive variable. Eigenvalues of axes one and two were 0.38 and 0.19 respectively
Mentions: The community structure of Oribatida changed along the altitudinal gradient (DFA: Wilks’ Lambda 0.0097; F9,14 = 9.38; P = 0.001), and differed significantly between each of the four altitudes as indicated by Mahalanobis distances (MD). Differences were most pronounced between 2,150 and 2,300 m (MD = 74.11; P = 0.0006), and least pronounced between 1,850 and 2,300 m (MD = 13.37; P = 0.045). PCA with the calibrated densities of Oribatida also showed that the community structure did not gradually change from the lower to the higher altitudes; rather the community structure of Oribatida at lower altitudes was similar to that at the highest altitude (Fig. 3). Galumnidae dominated at 1,850 m, parthenogenetic taxa such as (most) Suctobelbidae, Oppiella nova and Rostrozetes sp. were dominant at 2,000 m; Rhynchoribates ecuadoriensis, Epidamaeus sp. and Brachyoppiella periculosa had their highest relative densities at 2,150 m, whereas the parthenogenetic species Malaconothrus angulatus was the only Oribatida species that had its highest relative abundance at 2,300 m (Fig. 3).Fig. 3

Bottom Line: However, as we predicted the density of each of the groups decreased with soil depth.Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata.The oribatid mite community on bark did not differ significantly from that in soil.

View Article: PubMed Central - PubMed

Affiliation: Technische Universität Darmstadt, Institut für Zoologie, Schnittspahnstrasse 3, Darmstadt, Germany.

ABSTRACT
Microarthropod communities in the soil and on the bark of trees were investigated along an elevation gradient (1,850, 2,000, 2,150, 2,300 m) in a tropical montane rain forest in southern Ecuador. We hypothesised that the density of microarthropods declines with depth in soil and increases with increasing altitude mainly due to the availability of resources, i.e. organic matter. In addition, we expected bark and soil communities to differ strongly, since the bark of trees is more exposed to harsher factors. In contrast to our hypothesis, the density of major microarthropod groups (Collembola, Oribatida, Gamasina, Uropodina) was generally low and decreased with altitude. However, as we predicted the density of each of the groups decreased with soil depth. Density of microarthropods on tree bark was lower than in soil. Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata. The oribatid mite community on bark did not differ significantly from that in soil. The number of oribatid mite species declined with altitude (24, 23, 17 and 13 species at 1,850, 2,000, 2,150 and 2,300 m, respectively). Rarefaction curves indicate that overall about 50 oribatid mite species are to be expected along the studied altitudinal gradient. Results of this study indicate (1) that microarthropods may be limited by the quality of resources at high altitudes and by the amount of resources at deeper soil layers, and (2) that the bark of trees and the soil are habitats of similar quality for oribatid mites.

Show MeSH
Related in: MedlinePlus