Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?

Floristic Quality Assessment (FQA) metrics are used to assess the conservation value of natural areas based on the composition of their plant communities. FQA is based on coefficients of conservatism (C-values). C-values are regional, expert-assigned values, which range from 0 to 10 to reflect a tax...

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Main Authors: Jack Zinnen, Greg Spyreas, David N. Zaya, Jeffrey W. Matthews
Format: Article
Language:English
Published: Elsevier 2021-02-01
Series:Ecological Indicators
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1470160X20310177
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author Jack Zinnen
Greg Spyreas
David N. Zaya
Jeffrey W. Matthews
author_facet Jack Zinnen
Greg Spyreas
David N. Zaya
Jeffrey W. Matthews
author_sort Jack Zinnen
collection DOAJ
description Floristic Quality Assessment (FQA) metrics are used to assess the conservation value of natural areas based on the composition of their plant communities. FQA is based on coefficients of conservatism (C-values). C-values are regional, expert-assigned values, which range from 0 to 10 to reflect a taxon’s fidelity to high quality natural areas and its relative tolerance to modern human impacts. Approximately half of FQA publications assert without evidence that plant species with lower C-values are more generalist, whereas species with higher C-values are habitat specialists. The connection between specialization and C-values has never been investigated. Our primary objective was to test the claim that ecological specialization is associated with C-values. We first used the “theta (θ) method,” based on species co-occurrences, to estimate niche width for 274 species in 598 wetlands, grasslands, and forests in Illinois, USA. As a secondary proxy for niche width, we counted the habitat preferences of all Illinois vascular taxa listed from the Illinois Plant Information Network (ILPIN). For θ in grasslands and wetlands, and for ILPIN habitat counts, the lowest and highest C-values were associated with greater ecological specialization, whereas species with low to intermediate C-values were the most generalist. In forests, we found weaker, negatively linear relationships between C-values and θ, indicating that species with a high conservation value (i.e. conservative) were the most specialized. However, when shrub and canopy layers were combined with the herbaceous layer data in forests, we did not find an association between C-values and specialization. We also reanalyzed the data to determine the effect of non-native species on the relationship between niche width and C-values because non-native species, by default, receive C-values of 0. Removing non-native species from the analyses did not influence our conclusions. Both methods to measure specialization suggested there is a weak relationship between C-values and ecological specialization. Our findings support the common claim that some conservative species are more specialized than species with intermediate or low C-values. However, we found the general C-value and specialization relationship is more complex than assumed by many FQA publications because if it exists, it is not necessarily linear, i.e., species with low C-values are often specialists. Specialization and niche width could be latent components of C-values, but FQA users should avoid defining species conservatism by niche and specialization.
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spelling doaj.art-8a6510d3e01d40f2a112a42d95d6b1d42022-12-21T23:10:25ZengElsevierEcological Indicators1470-160X2021-02-01121107078Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?Jack Zinnen0Greg Spyreas1David N. Zaya2Jeffrey W. Matthews3Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave., Urbana, IL 61801, United States; Corresponding author.Illinois Natural History Survey, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL 61820, United StatesIllinois Natural History Survey, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL 61820, United StatesDepartment of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave., Urbana, IL 61801, United StatesFloristic Quality Assessment (FQA) metrics are used to assess the conservation value of natural areas based on the composition of their plant communities. FQA is based on coefficients of conservatism (C-values). C-values are regional, expert-assigned values, which range from 0 to 10 to reflect a taxon’s fidelity to high quality natural areas and its relative tolerance to modern human impacts. Approximately half of FQA publications assert without evidence that plant species with lower C-values are more generalist, whereas species with higher C-values are habitat specialists. The connection between specialization and C-values has never been investigated. Our primary objective was to test the claim that ecological specialization is associated with C-values. We first used the “theta (θ) method,” based on species co-occurrences, to estimate niche width for 274 species in 598 wetlands, grasslands, and forests in Illinois, USA. As a secondary proxy for niche width, we counted the habitat preferences of all Illinois vascular taxa listed from the Illinois Plant Information Network (ILPIN). For θ in grasslands and wetlands, and for ILPIN habitat counts, the lowest and highest C-values were associated with greater ecological specialization, whereas species with low to intermediate C-values were the most generalist. In forests, we found weaker, negatively linear relationships between C-values and θ, indicating that species with a high conservation value (i.e. conservative) were the most specialized. However, when shrub and canopy layers were combined with the herbaceous layer data in forests, we did not find an association between C-values and specialization. We also reanalyzed the data to determine the effect of non-native species on the relationship between niche width and C-values because non-native species, by default, receive C-values of 0. Removing non-native species from the analyses did not influence our conclusions. Both methods to measure specialization suggested there is a weak relationship between C-values and ecological specialization. Our findings support the common claim that some conservative species are more specialized than species with intermediate or low C-values. However, we found the general C-value and specialization relationship is more complex than assumed by many FQA publications because if it exists, it is not necessarily linear, i.e., species with low C-values are often specialists. Specialization and niche width could be latent components of C-values, but FQA users should avoid defining species conservatism by niche and specialization.http://www.sciencedirect.com/science/article/pii/S1470160X20310177Coefficient of conservatismFloristic Quality AssessmentGeneralistsIndicator valueNon-native speciesRealized niche breadth
spellingShingle Jack Zinnen
Greg Spyreas
David N. Zaya
Jeffrey W. Matthews
Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
Ecological Indicators
Coefficient of conservatism
Floristic Quality Assessment
Generalists
Indicator value
Non-native species
Realized niche breadth
title Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
title_full Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
title_fullStr Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
title_full_unstemmed Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
title_short Niche ecology in Floristic Quality Assessment: Are species with higher conservatism more specialized?
title_sort niche ecology in floristic quality assessment are species with higher conservatism more specialized
topic Coefficient of conservatism
Floristic Quality Assessment
Generalists
Indicator value
Non-native species
Realized niche breadth
url http://www.sciencedirect.com/science/article/pii/S1470160X20310177
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