Seedling resistance, tolerance and escape from herbivores: insights from co-dominant canopy tree species in a resource-poor African rain forest

Norghauer, Julian Martin; Glauser, Gaëtan; Newbery, David McClintock (2014). Seedling resistance, tolerance and escape from herbivores: insights from co-dominant canopy tree species in a resource-poor African rain forest. Functional Ecology, 28(6), pp. 1426-1439. Blackwell Scientific Publications 10.1111/1365-2435.12279

[img] Text
Norghauer-Newberg.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (610kB) | Request a copy

* Although plants can reduce the impacts of herbivory in multiple ways, these defensive traits are often studied in isolation and an understanding of the resulting strategies is incomplete. * In the study reported here, empirical evidence was simultaneously evaluated for the three main sets of traits available to plants: (i) resistance through constitutive leaf traits, (ii) tolerance to defoliation and (iii) escape in space, for three caesalpiniaceous tree species Microberlinia bisulcata, Tetraberlinia bifoliolata and T. korupensis, which co-dominate groves within the lowland primary rain forest of Korup National Park (Cameroon). * Mesh cages were placed around individual wild seedlings to exclude insect herbivores at 41 paired canopy gap and understorey locations. After following seedling growth and survival for c. 2 years, caged and control treatments were removed, leaves harvested to determine nutrient and phenolic concentrations, leaf mass per area estimated, and seedling performance in gaps followed for a further c. 2 years to quantify tolerance to the leaf harvesting. * The more nutrient-rich leaves of the weakly shade-tolerant M. bisulcata were damaged much more in gaps than the two strongly shade-tolerant Tetraberlinia species, which had higher leaf mass per area and concentrations of total phenols. Conversely, the faster-growing M. bisulcata was better able to tolerate defoliation in terms of height growth (reflushing capacity), but not at maintaining overall leaf numbers, than the other two species. * Across gaps, insect-mediated Janzen–Connell effects were most pronounced for M. bisulcata, less so for T. korupensis, and not detectable for T. bifoliolata. The three species differed distinctly in their secondary metabolic profiles. * Taken together, the results suggested a conceptual framework linking the three sets of traits, one in which the three co-dominant species adopt different strategies towards herbivore pressure depending on their different responses to light availability. This study is one of the first in a natural forest ecosystem to examine resistance to, tolerance of, and escape from herbivory among a group of co-occurring tropical tree species.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Vegetation Ecology [discontinued]

UniBE Contributor:

Norghauer, Julian Martin and Newbery, David McClintock

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0269-8463

Publisher:

Blackwell Scientific Publications

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

07 Nov 2014 17:06

Last Modified:

28 Apr 2016 11:18

Publisher DOI:

10.1111/1365-2435.12279

Uncontrolled Keywords:

canopy gap disturbances, growth–resistance trade-off, herbivory, Janzen–Connell effects, leaf phenolics, plant–insect interactions, tolerance to defoliation, tropical Africa

BORIS DOI:

10.7892/boris.59910

URI:

https://boris.unibe.ch/id/eprint/59910

Actions (login required)

Edit item Edit item
Provide Feedback