Impacts of herbivorous insects on decomposer communities during the early stages of primary succession in a semi-arid woodland

Aimée T. Classen, Jennie DeMarco, Stephen C. Hart, Thomas G Whitham, Neil S Cobb, George W Koch

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Changes in nutrient inputs due to aboveground herbivory may influence the litter and soil microbial community responsible for processes such as decomposition. The mesophyll-feeding scale insect (Matsucoccus acalyptus) found near Sunset Crater National Monument in northern Arizona, USA significantly increases piñon (Pinus edulis) needle litter nitrogen (N) and phosphorus (P) concentrations by 50%, as well as litter inputs to soil by 21%. Because increases in needle litter quality and quantity of this magnitude should affect the microbial communities responsible for decomposition, we tested the hypothesis that insect herbivory causes a shift in soil microbial and litter microarthropod function. Four major findings result from this research: (1) Despite increases in needle inputs due to herbivory, soil carbon (C) was 56% lower beneath scale-susceptible trees than beneath resistant trees; however, soil moisture, N, and pH were similar among treatments. (2) Microbial biomass was 80% lower in soils beneath scale-susceptible trees when compared to resistant trees in the dry season, while microbial enzyme activities were lower beneath susceptible trees in the wet season. (3) Bacterial community-level physiological profiles differed significantly between susceptible and resistant trees during the dry season but not during the wet season. (4) There was a 40% increase in Oribatida and 23% increase in Prostigmata in susceptible needle litter relative to resistant litter. Despite these changes, the magnitude of microbial biomass, activity, and community structure response to herbivory was lower than expected and appears to take a long time to develop. These results suggest that herbivores impact soils in subtle, but important ways; we suggest that while litter chemistry may strongly mediate soil fertility and microbial communities in mesic ecosystems, the influence is lower than expected in this primary succession xeric ecosystem where season mediates differences in microbial populations. Understanding how insect herbivores alter the distribution of susceptible and resistant trees and their associated decomposer communities in arid environments may lead to better prediction of how these ecosystems respond to climatic change.

Original languageEnglish (US)
Pages (from-to)972-982
Number of pages11
JournalSoil Biology and Biochemistry
Volume38
Issue number5
DOIs
StatePublished - May 2006

Fingerprint

primary succession
phytophagous insects
Herbivory
Insects
woodlands
woodland
litter
Soil
insect
herbivores
Soils
Needles
herbivory
Ecosystems
microbial communities
soil
Ecosystem
microbial community
Matsucoccus acalyptus
microbial biomass

Keywords

  • Community-level physiological profiles
  • Enzyme activity
  • Insect herbivory
  • Insect-susceptible and resistant trees
  • Litter microarthropods
  • Microbial biomass
  • Piñon-juniper woodlands
  • Semi-arid

ASJC Scopus subject areas

  • Soil Science
  • Biochemistry
  • Ecology

Cite this

Impacts of herbivorous insects on decomposer communities during the early stages of primary succession in a semi-arid woodland. / Classen, Aimée T.; DeMarco, Jennie; Hart, Stephen C.; Whitham, Thomas G; Cobb, Neil S; Koch, George W.

In: Soil Biology and Biochemistry, Vol. 38, No. 5, 05.2006, p. 972-982.

Research output: Contribution to journalArticle

@article{d6a6b9da16c148e9a5e32dbef99475da,
title = "Impacts of herbivorous insects on decomposer communities during the early stages of primary succession in a semi-arid woodland",
abstract = "Changes in nutrient inputs due to aboveground herbivory may influence the litter and soil microbial community responsible for processes such as decomposition. The mesophyll-feeding scale insect (Matsucoccus acalyptus) found near Sunset Crater National Monument in northern Arizona, USA significantly increases pi{\~n}on (Pinus edulis) needle litter nitrogen (N) and phosphorus (P) concentrations by 50{\%}, as well as litter inputs to soil by 21{\%}. Because increases in needle litter quality and quantity of this magnitude should affect the microbial communities responsible for decomposition, we tested the hypothesis that insect herbivory causes a shift in soil microbial and litter microarthropod function. Four major findings result from this research: (1) Despite increases in needle inputs due to herbivory, soil carbon (C) was 56{\%} lower beneath scale-susceptible trees than beneath resistant trees; however, soil moisture, N, and pH were similar among treatments. (2) Microbial biomass was 80{\%} lower in soils beneath scale-susceptible trees when compared to resistant trees in the dry season, while microbial enzyme activities were lower beneath susceptible trees in the wet season. (3) Bacterial community-level physiological profiles differed significantly between susceptible and resistant trees during the dry season but not during the wet season. (4) There was a 40{\%} increase in Oribatida and 23{\%} increase in Prostigmata in susceptible needle litter relative to resistant litter. Despite these changes, the magnitude of microbial biomass, activity, and community structure response to herbivory was lower than expected and appears to take a long time to develop. These results suggest that herbivores impact soils in subtle, but important ways; we suggest that while litter chemistry may strongly mediate soil fertility and microbial communities in mesic ecosystems, the influence is lower than expected in this primary succession xeric ecosystem where season mediates differences in microbial populations. Understanding how insect herbivores alter the distribution of susceptible and resistant trees and their associated decomposer communities in arid environments may lead to better prediction of how these ecosystems respond to climatic change.",
keywords = "Community-level physiological profiles, Enzyme activity, Insect herbivory, Insect-susceptible and resistant trees, Litter microarthropods, Microbial biomass, Pi{\~n}on-juniper woodlands, Semi-arid",
author = "Classen, {Aim{\'e}e T.} and Jennie DeMarco and Hart, {Stephen C.} and Whitham, {Thomas G} and Cobb, {Neil S} and Koch, {George W}",
year = "2006",
month = "5",
doi = "10.1016/j.soilbio.2005.08.009",
language = "English (US)",
volume = "38",
pages = "972--982",
journal = "Soil Biology and Biochemistry",
issn = "0038-0717",
publisher = "Elsevier Limited",
number = "5",

}

TY - JOUR

T1 - Impacts of herbivorous insects on decomposer communities during the early stages of primary succession in a semi-arid woodland

AU - Classen, Aimée T.

AU - DeMarco, Jennie

AU - Hart, Stephen C.

AU - Whitham, Thomas G

AU - Cobb, Neil S

AU - Koch, George W

PY - 2006/5

Y1 - 2006/5

N2 - Changes in nutrient inputs due to aboveground herbivory may influence the litter and soil microbial community responsible for processes such as decomposition. The mesophyll-feeding scale insect (Matsucoccus acalyptus) found near Sunset Crater National Monument in northern Arizona, USA significantly increases piñon (Pinus edulis) needle litter nitrogen (N) and phosphorus (P) concentrations by 50%, as well as litter inputs to soil by 21%. Because increases in needle litter quality and quantity of this magnitude should affect the microbial communities responsible for decomposition, we tested the hypothesis that insect herbivory causes a shift in soil microbial and litter microarthropod function. Four major findings result from this research: (1) Despite increases in needle inputs due to herbivory, soil carbon (C) was 56% lower beneath scale-susceptible trees than beneath resistant trees; however, soil moisture, N, and pH were similar among treatments. (2) Microbial biomass was 80% lower in soils beneath scale-susceptible trees when compared to resistant trees in the dry season, while microbial enzyme activities were lower beneath susceptible trees in the wet season. (3) Bacterial community-level physiological profiles differed significantly between susceptible and resistant trees during the dry season but not during the wet season. (4) There was a 40% increase in Oribatida and 23% increase in Prostigmata in susceptible needle litter relative to resistant litter. Despite these changes, the magnitude of microbial biomass, activity, and community structure response to herbivory was lower than expected and appears to take a long time to develop. These results suggest that herbivores impact soils in subtle, but important ways; we suggest that while litter chemistry may strongly mediate soil fertility and microbial communities in mesic ecosystems, the influence is lower than expected in this primary succession xeric ecosystem where season mediates differences in microbial populations. Understanding how insect herbivores alter the distribution of susceptible and resistant trees and their associated decomposer communities in arid environments may lead to better prediction of how these ecosystems respond to climatic change.

AB - Changes in nutrient inputs due to aboveground herbivory may influence the litter and soil microbial community responsible for processes such as decomposition. The mesophyll-feeding scale insect (Matsucoccus acalyptus) found near Sunset Crater National Monument in northern Arizona, USA significantly increases piñon (Pinus edulis) needle litter nitrogen (N) and phosphorus (P) concentrations by 50%, as well as litter inputs to soil by 21%. Because increases in needle litter quality and quantity of this magnitude should affect the microbial communities responsible for decomposition, we tested the hypothesis that insect herbivory causes a shift in soil microbial and litter microarthropod function. Four major findings result from this research: (1) Despite increases in needle inputs due to herbivory, soil carbon (C) was 56% lower beneath scale-susceptible trees than beneath resistant trees; however, soil moisture, N, and pH were similar among treatments. (2) Microbial biomass was 80% lower in soils beneath scale-susceptible trees when compared to resistant trees in the dry season, while microbial enzyme activities were lower beneath susceptible trees in the wet season. (3) Bacterial community-level physiological profiles differed significantly between susceptible and resistant trees during the dry season but not during the wet season. (4) There was a 40% increase in Oribatida and 23% increase in Prostigmata in susceptible needle litter relative to resistant litter. Despite these changes, the magnitude of microbial biomass, activity, and community structure response to herbivory was lower than expected and appears to take a long time to develop. These results suggest that herbivores impact soils in subtle, but important ways; we suggest that while litter chemistry may strongly mediate soil fertility and microbial communities in mesic ecosystems, the influence is lower than expected in this primary succession xeric ecosystem where season mediates differences in microbial populations. Understanding how insect herbivores alter the distribution of susceptible and resistant trees and their associated decomposer communities in arid environments may lead to better prediction of how these ecosystems respond to climatic change.

KW - Community-level physiological profiles

KW - Enzyme activity

KW - Insect herbivory

KW - Insect-susceptible and resistant trees

KW - Litter microarthropods

KW - Microbial biomass

KW - Piñon-juniper woodlands

KW - Semi-arid

UR - http://www.scopus.com/inward/record.url?scp=33646076219&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646076219&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2005.08.009

DO - 10.1016/j.soilbio.2005.08.009

M3 - Article

VL - 38

SP - 972

EP - 982

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

IS - 5

ER -