Insect herbivory increases from forest to alpine tundra in Arctic mountains ...
Current theory holds that the intensity of biotic interactions decreases with increases in latitude and elevation; however, empirical data demonstrate great variation in the direction, strength, and shape of elevational changes in herbivory. The latitudinal position of mountains may be one important...
| Main Authors: | , , |
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| Format: | Dataset |
| Language: | English |
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Dryad
2021
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.5061/dryad.7m0cfxpw6 https://datadryad.org/stash/dataset/doi:10.5061/dryad.7m0cfxpw6 |
| Summary: | Current theory holds that the intensity of biotic interactions decreases with increases in latitude and elevation; however, empirical data demonstrate great variation in the direction, strength, and shape of elevational changes in herbivory. The latitudinal position of mountains may be one important source of this variation, but the acute shortage of data from polar mountains hampers exploration of latitude effects on elevational changes in herbivory. Here, we reduce this knowledge gap by testing the prediction that a decrease in herbivory occurs with increasing elevation from forest to alpine tundra. We examined six elevation gradients located in three Arctic mountain ranges. Across the ten most abundant evergreen and deciduous woody plant species, relative losses of foliage to insect herbivores were 2.2-fold greater at the highest elevations (alpine tundra) than in mid-elevation birch woodlands or low-elevation coniferous forests. Plant quality for herbivores (quantified by specific leaf area) ... : The study was replicated at four hierarchical levels: three mountain ranges, six gradients, three elevations within each gradient corresponding to three vegetation types, and ten plant species. We selected our uppermost sites in alpine tundra (high elevation hereafter), at the upper distribution limit of our study trees (Scots pine, Norway spruce and mountain birch). Our intermediate sites (mid-elevation, hereafter) were located in subalpine birch woodland. The lowest sites (low elevation, hereafter) were chosen in closed canopy coniferous forests at the foot of the respective mountains. The difference in elevation between the tundra and forest sites ranged from 170 to 325 m (Table S1). We measured herbivory in ten plant species: five trees and tall shrubs (evergreen P. abies, P. sylvestris and Juniperus communis L.; deciduous B. pubescens and Salix phylicifolia L.) and five low shrubs (evergreen V. vitis-idaea and deciduous V. myrtillus, V. uliginosum L., S. glauca L. and B. nana L.). Four of these species ... |
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