Impacts of insect frass and cadavers on soil surface litter decomposition along a tropical forest temperature gradient
(2022) In Ecology and Evolution 12(9).- Abstract
- Insect herbivores play important roles in shaping many ecosystem processes, but how climate change will alter the effects of insect herbivory are poorly understood. To address this knowledge gap, we quantified for the first time how insect frass and cadavers affected leaf litter decomposition rates and nutrient release along a highly constrained 4.3°C mean annual temperature (MAT) gradient in a Hawaiian montane tropical wet forest. We constructed litterbags of standardized locally sourced leaf litter, with some amended with insect frass + cadavers to produce treatments designed to simulate ambient (Control = no amendment), moderate (Amended-Low = 2 × Control level), or severe (Amended-High = 11 × Control level) insect outbreak events.... (More)
- Insect herbivores play important roles in shaping many ecosystem processes, but how climate change will alter the effects of insect herbivory are poorly understood. To address this knowledge gap, we quantified for the first time how insect frass and cadavers affected leaf litter decomposition rates and nutrient release along a highly constrained 4.3°C mean annual temperature (MAT) gradient in a Hawaiian montane tropical wet forest. We constructed litterbags of standardized locally sourced leaf litter, with some amended with insect frass + cadavers to produce treatments designed to simulate ambient (Control = no amendment), moderate (Amended-Low = 2 × Control level), or severe (Amended-High = 11 × Control level) insect outbreak events. Multiple sets of these litterbags were deployed across the MAT gradient, with individual litterbags collected periodically over one year to assess how rising MAT altered the effects of insect deposits on litter decomposition rates and nitrogen (N) release. Increased MAT and insect inputs additively increased litter decomposition rates and N immobilization rates, with effects being stronger for Amended-High litterbags. However, the apparent temperature sensitivity (Q10) of litter decomposition was not clearly affected by amendments. The effects of adding insect deposits in this study operated differently than the slower litter decomposition and greater N mobilization rates often observed in experiments which use chemical fertilizers (e.g., urea, ammonium nitrate). Further research is required to understand mechanistic differences between amendment types. Potential increases in outbreak-related herbivore deposits coupled with climate warming will accelerate litter decomposition and nutrient cycling rates with short-term consequences for nutrient cycling and carbon storage in tropical montane wet forests. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/d4605ca2-d9b4-428a-a7d9-fcb2800d55a4
- author
- Hwang, Bernice LU ; Giardina, Christian ; Litton, Creighton ; Francisco, Kainana ; Pacheco, Cody ; Thomas, Naneaikealaula ; Uehara, Tyler and Metcalfe, Dan LU
- organization
- publishing date
- 2022-09-21
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- insect herbivor, nitrogen mineralizati, nutrient cycling, Q10
- in
- Ecology and Evolution
- volume
- 12
- issue
- 9
- pages
- 13 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:36188494
- scopus:85139125889
- ISSN
- 2045-7758
- DOI
- 10.1002/ece3.9322
- project
- Impacts and drivers of insect herbivory on element cycling in forests globally
- language
- English
- LU publication?
- yes
- id
- d4605ca2-d9b4-428a-a7d9-fcb2800d55a4
- date added to LUP
- 2022-10-13 15:43:52
- date last changed
- 2022-10-19 12:07:00
@article{d4605ca2-d9b4-428a-a7d9-fcb2800d55a4,
abstract = {{Insect herbivores play important roles in shaping many ecosystem processes, but how climate change will alter the effects of insect herbivory are poorly understood. To address this knowledge gap, we quantified for the first time how insect frass and cadavers affected leaf litter decomposition rates and nutrient release along a highly constrained 4.3°C mean annual temperature (MAT) gradient in a Hawaiian montane tropical wet forest. We constructed litterbags of standardized locally sourced leaf litter, with some amended with insect frass + cadavers to produce treatments designed to simulate ambient (Control = no amendment), moderate (Amended-Low = 2 × Control level), or severe (Amended-High = 11 × Control level) insect outbreak events. Multiple sets of these litterbags were deployed across the MAT gradient, with individual litterbags collected periodically over one year to assess how rising MAT altered the effects of insect deposits on litter decomposition rates and nitrogen (N) release. Increased MAT and insect inputs additively increased litter decomposition rates and N immobilization rates, with effects being stronger for Amended-High litterbags. However, the apparent temperature sensitivity (Q10) of litter decomposition was not clearly affected by amendments. The effects of adding insect deposits in this study operated differently than the slower litter decomposition and greater N mobilization rates often observed in experiments which use chemical fertilizers (e.g., urea, ammonium nitrate). Further research is required to understand mechanistic differences between amendment types. Potential increases in outbreak-related herbivore deposits coupled with climate warming will accelerate litter decomposition and nutrient cycling rates with short-term consequences for nutrient cycling and carbon storage in tropical montane wet forests.}},
author = {{Hwang, Bernice and Giardina, Christian and Litton, Creighton and Francisco, Kainana and Pacheco, Cody and Thomas, Naneaikealaula and Uehara, Tyler and Metcalfe, Dan}},
issn = {{2045-7758}},
keywords = {{insect herbivor; nitrogen mineralizati; nutrient cycling; Q10}},
language = {{eng}},
month = {{09}},
number = {{9}},
publisher = {{Wiley-Blackwell}},
series = {{Ecology and Evolution}},
title = {{Impacts of insect frass and cadavers on soil surface litter decomposition along a tropical forest temperature gradient}},
url = {{http://dx.doi.org/10.1002/ece3.9322}},
doi = {{10.1002/ece3.9322}},
volume = {{12}},
year = {{2022}},
}