Interactions among stressors may be weak

Implications for management of freshwater macroinvertebrate communities

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7 Citations (Scopus)

Abstract

Aim: Ecological models that do not account for interactions among stressors, if interactions are important, could be inaccurate and lead to inefficient conservation strategies. Conversely, if interactions are not important (i.e., stressors operate largely independently), then actions concentrating on a stressor-by-stressor basis would be warranted. Here, we investigated whether interactions among multiple stressors affected widely used indices of freshwater macroinvertebrate biodiversity, which are sensitive to environmental change at management-relevant scales (i.e., reaches and catchments). Location: State of Victoria, south-eastern Australia. Methods: We used a 7,418-sample dataset for stream macroinvertebrates from 2,165 sites distributed over 237,630 km2 for 20 years. We calculated the interactive effects on stream macroinvertebrates of stressors operating at different scales, namely vegetation loss at the catchment and reach scales and hydrological change and salinization at the local scale. The importance of interactions among multiple stressors was assessed by comparing the cross-validated predictive performance of models with and without multiple stressor interaction terms. Results: Cross-validated models explained 31%-63% of the variation in the macroinvertebrate responses. The most important stressors were catchment vegetation loss (the proportion of remaining native vegetation cover) and salinity. The inclusion of interaction terms did not increase cross-validated predictive performance, which indicates that there was little evidence that interactions among stressors were important for explaining variation in commonly used freshwater macroinvertebrate condition indices. Main conclusions: Interactions among vegetation, salinity and hydrological change stressors may not always be of importance for determining patterns of stream macroinvertebrate biodiversity, so that such interactions may not necessarily be critical considerations for catchment and reach scale management, at least if based on these or comparable condition indices. The mitigation of the impacts of vegetation loss, salinization and hydrological change stressors one-by-one probably is sufficient to guide conservation activities and might be advantageous if socio-political contexts make it difficult to address interactions among stressors.

Original languageEnglish
Pages (from-to)939-950
Number of pages12
JournalDiversity and Distributions
Volume24
Issue number7
DOIs
Publication statusPublished - Jul 2018

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macroinvertebrates
macroinvertebrate
hydrological change
catchment
vegetation
salinization
Victoria (Australia)
biodiversity
salinity
concentrating
vegetation cover
environmental change
mitigation
loss
index
sampling

Cite this

@article{34949faa1c804f61938db45f7f1e36a7,
title = "Interactions among stressors may be weak: Implications for management of freshwater macroinvertebrate communities",
abstract = "Aim: Ecological models that do not account for interactions among stressors, if interactions are important, could be inaccurate and lead to inefficient conservation strategies. Conversely, if interactions are not important (i.e., stressors operate largely independently), then actions concentrating on a stressor-by-stressor basis would be warranted. Here, we investigated whether interactions among multiple stressors affected widely used indices of freshwater macroinvertebrate biodiversity, which are sensitive to environmental change at management-relevant scales (i.e., reaches and catchments). Location: State of Victoria, south-eastern Australia. Methods: We used a 7,418-sample dataset for stream macroinvertebrates from 2,165 sites distributed over 237,630 km2 for 20 years. We calculated the interactive effects on stream macroinvertebrates of stressors operating at different scales, namely vegetation loss at the catchment and reach scales and hydrological change and salinization at the local scale. The importance of interactions among multiple stressors was assessed by comparing the cross-validated predictive performance of models with and without multiple stressor interaction terms. Results: Cross-validated models explained 31{\%}-63{\%} of the variation in the macroinvertebrate responses. The most important stressors were catchment vegetation loss (the proportion of remaining native vegetation cover) and salinity. The inclusion of interaction terms did not increase cross-validated predictive performance, which indicates that there was little evidence that interactions among stressors were important for explaining variation in commonly used freshwater macroinvertebrate condition indices. Main conclusions: Interactions among vegetation, salinity and hydrological change stressors may not always be of importance for determining patterns of stream macroinvertebrate biodiversity, so that such interactions may not necessarily be critical considerations for catchment and reach scale management, at least if based on these or comparable condition indices. The mitigation of the impacts of vegetation loss, salinization and hydrological change stressors one-by-one probably is sufficient to guide conservation activities and might be advantageous if socio-political contexts make it difficult to address interactions among stressors.",
keywords = "additive, antagonistic, freshwater communities, multiple pressures, non-additive, synergistic",
author = "Jarrod Kath and Thomson, {James R.} and Thompson, {Ross M.} and Kefford, {Ben J.} and Dyer, {Fiona J.} and {Mac Nally}, Ralph",
year = "2018",
month = "7",
doi = "10.1111/ddi.12737",
language = "English",
volume = "24",
pages = "939--950",
journal = "Diversity and Distributions",
issn = "1366-9516",
publisher = "Wiley-Blackwell",
number = "7",

}

TY - JOUR

T1 - Interactions among stressors may be weak

T2 - Implications for management of freshwater macroinvertebrate communities

AU - Kath, Jarrod

AU - Thomson, James R.

AU - Thompson, Ross M.

AU - Kefford, Ben J.

AU - Dyer, Fiona J.

AU - Mac Nally, Ralph

PY - 2018/7

Y1 - 2018/7

N2 - Aim: Ecological models that do not account for interactions among stressors, if interactions are important, could be inaccurate and lead to inefficient conservation strategies. Conversely, if interactions are not important (i.e., stressors operate largely independently), then actions concentrating on a stressor-by-stressor basis would be warranted. Here, we investigated whether interactions among multiple stressors affected widely used indices of freshwater macroinvertebrate biodiversity, which are sensitive to environmental change at management-relevant scales (i.e., reaches and catchments). Location: State of Victoria, south-eastern Australia. Methods: We used a 7,418-sample dataset for stream macroinvertebrates from 2,165 sites distributed over 237,630 km2 for 20 years. We calculated the interactive effects on stream macroinvertebrates of stressors operating at different scales, namely vegetation loss at the catchment and reach scales and hydrological change and salinization at the local scale. The importance of interactions among multiple stressors was assessed by comparing the cross-validated predictive performance of models with and without multiple stressor interaction terms. Results: Cross-validated models explained 31%-63% of the variation in the macroinvertebrate responses. The most important stressors were catchment vegetation loss (the proportion of remaining native vegetation cover) and salinity. The inclusion of interaction terms did not increase cross-validated predictive performance, which indicates that there was little evidence that interactions among stressors were important for explaining variation in commonly used freshwater macroinvertebrate condition indices. Main conclusions: Interactions among vegetation, salinity and hydrological change stressors may not always be of importance for determining patterns of stream macroinvertebrate biodiversity, so that such interactions may not necessarily be critical considerations for catchment and reach scale management, at least if based on these or comparable condition indices. The mitigation of the impacts of vegetation loss, salinization and hydrological change stressors one-by-one probably is sufficient to guide conservation activities and might be advantageous if socio-political contexts make it difficult to address interactions among stressors.

AB - Aim: Ecological models that do not account for interactions among stressors, if interactions are important, could be inaccurate and lead to inefficient conservation strategies. Conversely, if interactions are not important (i.e., stressors operate largely independently), then actions concentrating on a stressor-by-stressor basis would be warranted. Here, we investigated whether interactions among multiple stressors affected widely used indices of freshwater macroinvertebrate biodiversity, which are sensitive to environmental change at management-relevant scales (i.e., reaches and catchments). Location: State of Victoria, south-eastern Australia. Methods: We used a 7,418-sample dataset for stream macroinvertebrates from 2,165 sites distributed over 237,630 km2 for 20 years. We calculated the interactive effects on stream macroinvertebrates of stressors operating at different scales, namely vegetation loss at the catchment and reach scales and hydrological change and salinization at the local scale. The importance of interactions among multiple stressors was assessed by comparing the cross-validated predictive performance of models with and without multiple stressor interaction terms. Results: Cross-validated models explained 31%-63% of the variation in the macroinvertebrate responses. The most important stressors were catchment vegetation loss (the proportion of remaining native vegetation cover) and salinity. The inclusion of interaction terms did not increase cross-validated predictive performance, which indicates that there was little evidence that interactions among stressors were important for explaining variation in commonly used freshwater macroinvertebrate condition indices. Main conclusions: Interactions among vegetation, salinity and hydrological change stressors may not always be of importance for determining patterns of stream macroinvertebrate biodiversity, so that such interactions may not necessarily be critical considerations for catchment and reach scale management, at least if based on these or comparable condition indices. The mitigation of the impacts of vegetation loss, salinization and hydrological change stressors one-by-one probably is sufficient to guide conservation activities and might be advantageous if socio-political contexts make it difficult to address interactions among stressors.

KW - additive

KW - antagonistic

KW - freshwater communities

KW - multiple pressures

KW - non-additive

KW - synergistic

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U2 - 10.1111/ddi.12737

DO - 10.1111/ddi.12737

M3 - Article

VL - 24

SP - 939

EP - 950

JO - Diversity and Distributions

JF - Diversity and Distributions

SN - 1366-9516

IS - 7

ER -