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The species composition of local flea assemblages at a small scale in two South American regions is predominantly driven by niche-based mechanisms

DOI:10.1007/s00436-022-07759-2
Authors:
Boris Krasnov at Ben-Gurion University of the Negev
Boris Krasnov
M. Fernanda López Berrizbeitia at National University of Tucuman
M. Fernanda López Berrizbeitia
Juliana P. Sanchez at National Scientific and Technical Research Council
Juliana P. Sanchez
Monica Diaz at National Scientific and Technical Research Council
Monica Diaz
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Abstract and Figures

We applied a step-down factor analysis (SDFA) and multi-site generalised dissimilarity modelling (MS-GDM) to local flea communities harboured by small mammals (i.e., collected at small sampling sites over a short time period) in two South American regions (Patagonia and the Northwestern Argentina) with the aim of understanding whether these communities were assembled via niche-based or dispersal-based processes. The SDFA allows us to determine whether clusters of flea assemblages across different types of climates, vegetation and soils can be distinguished (suggesting niche-based assembly). MS-GDM allows us to determine whether a substantial proportion of the variation in flea species turnover is explained by specific climate-associated, vegetation-associated and soil-associated variables (indicating niche-based assembly) or host turnover (indicating dispersal-based assembly). Mapping of assemblages on climate, vegetation and soil maps, according to their loadings on axis 1 or axis 2 of the SDFA, did not provide clear-cut results. Clusters of similar loadings could be recognized within some, but not other, climate, vegetation and soil types. However, MS-GDM demonstrated that the effect of environmental variables (especially air temperature) on flea compositional turnover was much stronger than that of host turnover, indicating the predominance of niche-based processes in local community assembly. A comparison of our results with those on the mechanisms that drive species assembly in regional communities allows us to conclude that local and regional communities result from the joint action of niche-based and dispersal-based processes, with the former more important at a smaller spatial scale and the latter at a larger spatial scale.
Zeta diversity decline (A rescaled values, B raw values) for local flea assemblages in Patagonia and the Northwestern Argentina (the Northwest)
Zeta diversity decline (A rescaled values, B raw values) for local flea assemblages in Patagonia and the Northwestern Argentina (the Northwest)
… 
Proportion of variance explained (r.² between observed and predicted zeta values) by the MS-GDMs that include either (a) environmental variables, distance and host zeta diversity (triangles) or (b) environmental variables and distance (squares) or (c) environmental variables only (circles) or (d) environmental variables and host zeta diversity (diamonds) in Patagonia and the Northwestern Argentina (the Northwest)
Proportion of variance explained (r.² between observed and predicted zeta values) by the MS-GDMs that include either (a) environmental variables, distance and host zeta diversity (triangles) or (b) environmental variables and distance (squares) or (c) environmental variables only (circles) or (d) environmental variables and host zeta diversity (diamonds) in Patagonia and the Northwestern Argentina (the Northwest)
… 
I-splines produced by the MS-GDMs for compositional turnover in local flea assemblages in Patagonia and showing the relative contributions of air temperature (principal component of mean temperature of the coldest, warmest, wettest and driest quarter; open squares), precipitation seasonality (closed squares), vapor pressure (circles), soil moisture (triangles) and host zeta diversity (diamonds)
I-splines produced by the MS-GDMs for compositional turnover in local flea assemblages in Patagonia and showing the relative contributions of air temperature (principal component of mean temperature of the coldest, warmest, wettest and driest quarter; open squares), precipitation seasonality (closed squares), vapor pressure (circles), soil moisture (triangles) and host zeta diversity (diamonds)
… 
I-splines produced by the MS-GDMs for compositional turnover in local flea assemblages in the Northwestern Argentina and showing the relative contributions of air temperature (principal component of mean temperature of the coldest, warmest, wettest and driest quarter; open squares), temperature seasonality (closed squares), sand and silt content (principal component of the two variables; circles), soil organic carbon content (principal component of soil organic carbon content, density and stocks; triangles) and host zeta diversity (diamonds)
I-splines produced by the MS-GDMs for compositional turnover in local flea assemblages in the Northwestern Argentina and showing the relative contributions of air temperature (principal component of mean temperature of the coldest, warmest, wettest and driest quarter; open squares), temperature seasonality (closed squares), sand and silt content (principal component of the two variables; circles), soil organic carbon content (principal component of soil organic carbon content, density and stocks; triangles) and host zeta diversity (diamonds)
… 
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Vol.:(0123456789)
1 3
https://doi.org/10.1007/s00436-022-07759-2
RESEARCH
The species composition oflocal flea assemblages atasmall
scale intwo South American regions ispredominantly driven
byniche‑based mechanisms
BorisR.Krasnov1· M.FernandaLópezBerrizbeitia2· JulianaP.Sanchez3· M.MónicaDíaz2· MarcelaLareschi4·
IrinaS.Khokhlova5· VasilyI.Grabovsky5
Received: 15 November 2022 / Accepted: 8 December 2022
© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022
Abstract
We applied a step-down factor analysis (SDFA) and multi-site generalised dissimilarity modelling (MS-GDM) to local flea
communities harboured by small mammals (i.e., collected at small sampling sites over a short time period) in two South
American regions (Patagonia and the Northwestern Argentina) with the aim of understanding whether these communities
were assembled via niche-based or dispersal-based processes. The SDFA allows us to determine whether clusters of flea
assemblages across different types of climates, vegetation and soils can be distinguished (suggesting niche-based assembly).
MS-GDM allows us to determine whether a substantial proportion of the variation in flea species turnover is explained by
specific climate-associated, vegetation-associated and soil-associated variables (indicating niche-based assembly) or host
turnover (indicating dispersal-based assembly). Mapping of assemblages on climate, vegetation and soil maps, accord-
ing to their loadings on axis 1 or axis 2 of the SDFA, did not provide clear-cut results. Clusters of similar loadings could
be recognized within some, but not other, climate, vegetation and soil types. However, MS-GDM demonstrated that the
effect of environmental variables (especially air temperature) on flea compositional turnover was much stronger than that
of host turnover, indicating the predominance of niche-based processes in local community assembly. A comparison of our
results with those on the mechanisms that drive species assembly in regional communities allows us to conclude that local
and regional communities result from the joint action of niche-based and dispersal-based processes, with the former more
important at a smaller spatial scale and the latter at a larger spatial scale.
Keywords Dispersal-based mechanisms· Fleas· Local assemblages· Niche-based mechanisms· South America
Handling Editor: Una Ryan
* Boris R. Krasnov
krasnov@bgu.ac.il
1 Mitrani Department ofDesert Ecology, Swiss Institute
forDryland Environmental andEnergy Research,
Jacob Blaustein Institutes forDesert Research, Ben-
Gurion University oftheNegev, Sede Boqer Campus,
MidreshetBen-Gurion, Israel
2 Programa de Conservación de los Murciélagos de
Argentina (PCMA) andInstituto de Investigaciones de
Biodiversidad Argentina (PIDBA)-CCT CONICET Noa
Sur (Consejo Nacional de Investigaciones Científicas
Y Técnicas), Facultad de Ciencias Naturales E IML,
UNT, andFundación Miguel Lillo, Miguel Lillo 251,
CP4000SanMigueldeTucumán, Argentina
3 Centro de Investigaciones y Transferencia del
Noroeste de La Provincia de Buenos Aires-CITNOBA
(UNNOBA-UNSAdA-CONICET), Pergamino, Argentina
4 Laboratorio de Ectoparásitos, Centro de Estudios
Parasitológicos Y de Vectores (CEPAVE)
(CONICET-UNLP), 45–53 Bv. 120 s/n e/ Av. 60 y Calle 64,
1900, LaPlata, Argentina
5 French Associates Institute forAgriculture
andBiotechnology ofDrylands, Ben-Gurion University
oftheNegev, Sede Boqer Campus, MidreshetBen-Gurion,
Israel
/ Published online: 14 December 2022
Parasitology Research (2023) 122:571–583
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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