DOI: 10.5061/dryad.d51c5b08s
title: Relationships between abiotic factors, foliage chemistry and herbivory in a tropical montane ecosystem

description: Herbivore-plant interactions are fundamental processes shaping ecosystems,
 yet their study is challenged by their complex connections within broader
 ecosystem processes, requiring a nuanced understanding of ecosystem
 dynamics. This study investigated the relationship between nutrient
 availability and insect herbivory in the Australian Wet Tropics. Our
 objectives were threefold. Firstly, to understand which factors influence
 nutrient availability for plants and herbivores across the landscape;
 secondly, to investigate how trees of different species respond to
 nutrient availability; and thirdly, to unravel how the relationships
 between resources and plant chemistry affect herbivory. We established a
 network of 25 study sites covering important abiotic gradients, including
 temperature, precipitation, and geology. Employing a hierarchical
 modelling approach, we assessed the influence of climate and geology on
 resource availability for plants, primarily in the form of soil nutrients.
 Then, we explored the influence of the above factors on the interaction
 between herbivory and foliage chemistry across three widespread rainforest
 tree species, comparing how these relationships emerged across genera. Our
 findings suggest an overarching influence of climate and geology over soil
 chemistry, foliar nitrogen, and insect herbivory, both directly and
 indirectly. However, individual constituents of soil fertility showed
 equivocal influences on spatial patterns of foliage chemistry once site
 geological origin was accounted for, suggesting a questionable
 relationship between soil nutrients and foliar composition. We have
 demonstrated that herbivore-plant interactions are complex dynamics
 regulated by an intricate web of relationships spanning different
 biogeochemical processes. While our results provide some support to the
 notion that herbivory is affected by resource availability, different
 species growing under the same conditions can show differing responses to
 the same resources, highlighting the importance of identifying specific
 limiting factors rather than simpler proxies of resource availability.
description: # Disentangling the relationship between herbivory pressure and resource
 availability in a tropical montane ecosystem ## Description of the data
 and file structure | Column | Description | Units | Scale | |
 ---------------- | ------------------------------------ | ---------------
 | --------------- | | Tree\_id | Individual ID for each sampled tree | - |
 Tree individual | | Site\_ID | Site ID | - | Plot | | Species | Tree
 species name | - | Species | | DMD | Dry matter digestibility | % | Tree
 individual | | N\_digestibility | Nitrogen digestibility content | Ratio
 (0-1) | Tree individual | | Total\_N | Total nitrogen content | % | Tree
 individual | | Geology | Geological origin | Soil type | Plot | | Elev |
 Elevation | M a.s.l. | Plot | | Map | Mean annual precipitation | Mm |
 Plot | | Mat | Mean annual temperature | Degrees Celsius | Plot | |
 Soil\_cn | Ratio of carbon-nitrogen in the soil | - | Plot | | Soil\_n |
 Total nitrogen content | % | Plot | | Soil\_p | Total phosphorus content |
 % | Plot | | Soil\_K | Total potassium content | cmol\_c/kg | Plot | |
 Soil\_na | Total sodium content | cmol\_c/kg | Plot | | Damage |
 Percentage of foliar damage | % | Tree individual | Missing data (NA)
 represents not available data. As explained in detail in the manuscript,
 soil information was not available for 2 sites and foliage damage was not
 possible for all samples due to constraints in the amount of material
 retrieved from canopy branches.