Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)

ABSTRACT Although many tree species frequently hybridize and backcross, management decisions in forestry and nature conservation are usually concentrated on pure species. Therefore, understanding which environmental factors drive the distribution and admixture of tree species on a local stand scale...

Full description

Saved in:
Bibliographic Details
Main Authors: Felix Zimmermann, Oliver Reutimann, Andri Baltensweiler, Lorenz Walthert, Jill K. Olofsson, Christian Rellstab
Format: Article
Language:English
Published: Wiley 2025-02-01
Series:Evolutionary Applications
Subjects:
Online Access:https://doi.org/10.1111/eva.70076
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850250396353691648
author Felix Zimmermann
Oliver Reutimann
Andri Baltensweiler
Lorenz Walthert
Jill K. Olofsson
Christian Rellstab
author_facet Felix Zimmermann
Oliver Reutimann
Andri Baltensweiler
Lorenz Walthert
Jill K. Olofsson
Christian Rellstab
author_sort Felix Zimmermann
collection DOAJ
description ABSTRACT Although many tree species frequently hybridize and backcross, management decisions in forestry and nature conservation are usually concentrated on pure species. Therefore, understanding which environmental factors drive the distribution and admixture of tree species on a local stand scale is of great interest to support decision‐making in the establishment and management of resilient forests. Here, we extensively sampled a mixed stand of hybridizing white oaks (Quercus petraea and Q. pubescens) near Lake Neuchâtel (Switzerland), where limestone and glacier moraine geologies coexist in proximity, to test whether micro‐environmental conditions can predict taxonomic distribution and genetic admixture. We collected DNA from bud tissue, individual soil samples, and extracted high‐resolution topographic data for 385 oak trees. We used 50 species‐discriminatory single nucleotide polymorphism (SNP) markers to determine the taxonomic composition and admixture levels of individual trees and tested their association with micro‐environmental conditions. We show that the trees' taxonomic distribution can be explained mainly by geographic position, soil pH, and potential rooting depth, a proxy for soil water availability. We found that admixed individuals tend to grow in habitats that are characteristic of the more drought‐tolerant species Q. pubescens rather than in intermediate habitats. Using in situ measurements, we are the first to show that fine‐scale variation in soil properties related to pH and water availability potentially drives the distribution of hybridizing tree species in a mixed stand. Microenvironmental variation therefore promotes local taxonomic diversity, facilitates admixture and adaptive introgression, and contributes to the resilience of forests under environmental change. Consequently, species such as white oaks should be managed and protected as a species complex rather than as pure species.
format Article
id doaj-art-fe731d84da124b47ae1c69d95fd812c0
institution OA Journals
issn 1752-4571
language English
publishDate 2025-02-01
publisher Wiley
record_format Article
series Evolutionary Applications
spelling doaj-art-fe731d84da124b47ae1c69d95fd812c02025-08-20T01:58:12ZengWileyEvolutionary Applications1752-45712025-02-01182n/an/a10.1111/eva.70076Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)Felix Zimmermann0Oliver Reutimann1Andri Baltensweiler2Lorenz Walthert3Jill K. Olofsson4Christian Rellstab5Swiss Federal Research Institute WSL Birmensdorf SwitzerlandInstitute of Integrative Biology ETH Zurich Zurich SwitzerlandSwiss Federal Research Institute WSL Birmensdorf SwitzerlandSwiss Federal Research Institute WSL Birmensdorf SwitzerlandSection for Forest and Landscape Ecology, Department of Geosciences and Natural Resource Management University of Copenhagen Kobenhavn DenmarkSwiss Federal Research Institute WSL Birmensdorf SwitzerlandABSTRACT Although many tree species frequently hybridize and backcross, management decisions in forestry and nature conservation are usually concentrated on pure species. Therefore, understanding which environmental factors drive the distribution and admixture of tree species on a local stand scale is of great interest to support decision‐making in the establishment and management of resilient forests. Here, we extensively sampled a mixed stand of hybridizing white oaks (Quercus petraea and Q. pubescens) near Lake Neuchâtel (Switzerland), where limestone and glacier moraine geologies coexist in proximity, to test whether micro‐environmental conditions can predict taxonomic distribution and genetic admixture. We collected DNA from bud tissue, individual soil samples, and extracted high‐resolution topographic data for 385 oak trees. We used 50 species‐discriminatory single nucleotide polymorphism (SNP) markers to determine the taxonomic composition and admixture levels of individual trees and tested their association with micro‐environmental conditions. We show that the trees' taxonomic distribution can be explained mainly by geographic position, soil pH, and potential rooting depth, a proxy for soil water availability. We found that admixed individuals tend to grow in habitats that are characteristic of the more drought‐tolerant species Q. pubescens rather than in intermediate habitats. Using in situ measurements, we are the first to show that fine‐scale variation in soil properties related to pH and water availability potentially drives the distribution of hybridizing tree species in a mixed stand. Microenvironmental variation therefore promotes local taxonomic diversity, facilitates admixture and adaptive introgression, and contributes to the resilience of forests under environmental change. Consequently, species such as white oaks should be managed and protected as a species complex rather than as pure species.https://doi.org/10.1111/eva.70076adaptationdroughthybridizationoaksQuercussoil
spellingShingle Felix Zimmermann
Oliver Reutimann
Andri Baltensweiler
Lorenz Walthert
Jill K. Olofsson
Christian Rellstab
Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
Evolutionary Applications
adaptation
drought
hybridization
oaks
Quercus
soil
title Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
title_full Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
title_fullStr Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
title_full_unstemmed Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
title_short Fine‐Scale Variation in Soil Properties Promotes Local Taxonomic Diversity of Hybridizing Oak Species (Quercus spp.)
title_sort fine scale variation in soil properties promotes local taxonomic diversity of hybridizing oak species quercus spp
topic adaptation
drought
hybridization
oaks
Quercus
soil
url https://doi.org/10.1111/eva.70076
work_keys_str_mv AT felixzimmermann finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp
AT oliverreutimann finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp
AT andribaltensweiler finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp
AT lorenzwalthert finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp
AT jillkolofsson finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp
AT christianrellstab finescalevariationinsoilpropertiespromoteslocaltaxonomicdiversityofhybridizingoakspeciesquercusspp