TY - JOUR T1 - The role of hybridization during ecological divergence of southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis) JF - Molecular Ecology Y1 - 2018 A1 - Mitra Menon A1 - Justin C. Bagley A1 - Christopher J. Friedline A1 - Amy V. Whipple A1 - Anna W. Schoettle A1 - Alejandro Leal-Saenz A1 - Christian Wehenkel A1 - Francisco Molina-Freaner A1 - Lluvia Flores-Renterıa A1 - M. Socorro Gonzalez-Elizondo A1 - Richard A. Sniezko A1 - Samuel A. Cushman A1 - Kristen M. Waring A1 - Andrew J. Eckert KW - conifers KW - ecological speciation KW - extrinsic barriers KW - hybrid zone KW - introgression KW - population genomics AB -
Interactions between extrinsic factors, such as disruptive selection and intrinsic factors,
such as genetic incompatibilities among loci, often contribute to the maintenance
of species boundaries. The relative roles of these factors in the establishment
of reproductive isolation can be examined using species pairs characterized by gene
flow throughout their divergence history. We investigated the process of speciation
and the maintenance of species boundaries between Pinus strobiformis and Pinus
flexilis. Utilizing ecological niche modelling, demographic modelling and genomic
cline analyses, we illustrated a divergence history with continuous gene flow. Our
results supported an abundance of advanced generation hybrids and a lack of loci
exhibiting steep transition in allele frequency across the hybrid zone. Additionally,
we found evidence for climate-associated variation in the hybrid index and niche
divergence between parental species and the hybrid zone. These results are consistent
with extrinsic factors, such as climate, being an important isolating mechanism.
A build-up of intrinsic incompatibilities and of coadapted gene complexes is also
apparent, although these appear to be in the earliest stages of development. This
supports previous work in coniferous species demonstrating the importance of extrinsic factors in facilitating speciation. Overall, our findings lend support to the
hypothesis that varying strength and direction of selection pressures across the long
lifespans of conifers, in combination with their other life history traits, delays the
evolution of strong intrinsic incompatibilities.
Southwestern white pine (Pinus strobiformis; SWWP) is a conifer species that occurs at mid to high elevations in
the mountains of Arizona, New Mexico, and northern Mexico. A key component of mixed conifer forests in the
region, SWWP is an important species for wildlife and biodiversity. The dual threats of the non-native fungal
pathogen that causes white pine blister rust (WPBR) and a warmer, drier projected future climate have created
an uncertain future for SWWP. In this study, we used a novel multi-scale optimization approach including an
ensemble of four species distribution modeling methods to explore the relationship between SWWP occurrence
and environmental variables based on climate, soil, and topography. Spatial projections of these models reflecting
the present climate provide an improved range map for this species that can be used to guide field data
collection and monitoring of WPBR outbreaks. Future projections based on two emissions scenarios and an
ensemble of 15 general circulation models project a large range shift and range contraction by 2080. Changes in
the future distribution were particularly extreme under the higher emissions scenario, with a more than 1000 km
northerly shift in the mean latitude and 500m increase in the mean elevation of the species’ suitable habitat.
This coincided with a range contraction of over 60% and a significant increase in habitat fragmentation. The
ability of SWWP to realize its projected future range will depend on colonization at the leading edge of the range
shift, including dispersal dynamics, resistance to WPBR, competition with other species, and genetic adaptations
to local climate. Our results provide information that can be used to guide monitoring efforts and inform conservation
planning for this keystone species.
Waring, K, Cushman, S, Eckert A, Flores Renteria, L, Sniezko, R, Still,C, Wehenkel, C, Whipple, A, and Wing, M. 2017. A holistic approach to genetic conservation in Pinus strobiformis. International Scientific Conference on Genetics of Populations: Progress and Perspectives, commemorating the 80th birthday of Academician Yury P. Altukhov and dedicated to the 45th Anniversary of the Laboratory of Population Genetics named after Yu. P. Altukhov, 17-21 April 2017, Zvenogorod Biological Station, Russia.
JF - International Scientific Conference on Genetics of Populations Progress and Perspectives commemorating the 80th birthday of Academician Altukhov and dedicated to the 45th Anniversary of the Laboratory of Population Genetics named after Yu P Biological Sta T3 - International Scientific Conference on Genetics of Populations Progress and Perspectives commemorating the 80th birthday of Academician Altukhov and dedicated to the 45th Anniversary of the Laboratory of Population Genetics named after Yu P Biological Sta CY - Zvenogorod Biological Station, Russia VL - 2017 N1 - [Original String]:Waring, K, Cushman, S, Eckert A, Flores Renteria, L, Sniezko, R, Still, C, Wehenkel, C, Whipple, A, and Wing, M. 2017. A holistic approach to genetic conservation in Pinus strobiformis. International Scientific Conference on Genetics of Populations: Progress and Perspectives, commemorating the 80th birthday of Academician Yury P. Altukhov and dedicated to the 45th Anniversary of the Laboratory of Population Genetics named after Yu. P. Altukhov, 17-21 April 2017, Zvenogorod Biological Station, Russia. ER - TY - CONF T1 - Southwestern white pine performance across an elevational gradient. T2 - National Silviculture Workshop Y1 - 2017 A1 - DaBell,J A1 - K Waring A1 - TE Kolb A1 - AV Whipple JF - National Silviculture Workshop T3 - National Silviculture Workshop CY - Flagstaff, Arizona, USA ER - TY - CONF T1 - Southwestern white pine performance across an elevational gradient. T2 - North American Forest Ecology Workshop Y1 - 2017 A1 - DaBell,J A1 - K Waring A1 - TE Kolb A1 - AV Whipple AB -DaBell, J., Waring, K., Kolb, T. and Whipple, A. 2017. Southwesternwhite pine performance across an elevational gradient. North American Forest Ecology Workshop, June 18-22, 2017, Edmonton, Canada. Also presented at the National Silviculture Workshop, July 18-20, 2017, Flagstaff, AZ.
JF - North American Forest Ecology Workshop T3 - North American Forest Ecology Workshop CY - Edmonton Canada VL - 2017 N1 - [Original String]:DaBell, J., Waring, K., Kolb, T. and Whipple, A. 2017. Southwestern white pine performance across an elevational gradient. North American Forest Ecology Workshop, June 18-22, 2017, Edmonton, Canada. Also presented at the National Silviculture Workshop, July 18-20, 2017, Flagstaff, AZ. ER - TY - CONF T1 - Collaborative research for sustainable management of southwestern white pine. T2 - Society of American Foresters National Convention Y1 - 2016 A1 - K Waring A1 - Cushman,S A1 - Eckert,A A1 - L Flores-Renteria A1 - Lintz,H A1 - R Sniezko A1 - Still,C A1 - Wehenkel,C A1 - AV Whipple A1 - Wing,M AB -
Waring, K., Cushman, S., Eckert, A., Flores-Renteria, L., Lintz, H.,Sniezko, R., Still, C., Wehenkel, C., Whipple, A., and Wing, M. 2016. Collaborative research for sustainable management of southwestern white pine. Society of American Foresters National Convention, November 2-5, 2016, Madison, WI.
The persistence of some tree species is threatened by combinations of novel abiotic and biotic stressors. To examine the hypothesis that Pinus strobiformis Engelm., a tree threatened by an invasive forest pathogen and a changing climate, exhibits intraspecific genetic variation in adaptive traits, we conducted a common garden study of seedlings at one location with two watering regimes using 24 populations. Four key findings emerged: (i) growth and physiological traits were low to moderately differentiated among populations but differentiation was high for some traits in water-stressed populations; (ii) seedlings from warmer climates grew larger, had higher stomatal density and were more water-use efficient (as measured by the carbon isotope ratio) than populations from colder climates; (iii) seedlings from the northern edge of the species' distribution had lower water-use efficiency, higher stomatal conductance, slower growth and longer survival in a lethal drought experiment compared with seedlings from more southern populations; and (iv) based on non-metric multidimensional scaling analyses, populations clustered into southern and northern groups, which did not correspond to current seed transfer zones. Our discovery of a clinal geographic pattern of genetic variation in adaptive traits of P. strobiformis seedlings will be useful in developing strategies to maintain the species during ongoing climate change and in the face of an invasive pathogen.
VL - 36 SN - 0829-318X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=27344065&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 10 ER - TY - JOUR T1 - The impacts of increasing drought on forest dynamics, structure, and biodiversity in the United States. JF - Global change biology Y1 - 2016 A1 - James S Clark A1 - Iverson,Louis A1 - Woodall,Christopher W A1 - Allen,Craig D A1 - Bell,David M A1 - Bragg,Don C A1 - D'Amato,Anthony W A1 - Davis,Frank W A1 - Hersh,Michelle H A1 - Ibanez,Ines A1 - Jackson,Stephen T A1 - Matthews,Stephen A1 - Pederson,Neil A1 - Peters,Matthew A1 - Schwartz,Mark W A1 - Waring,Kristen M A1 - Zimmermann,Niklaus E KW - biodiversity KW - Droughts KW - Ecosystem KW - Forests KW - Trees KW - United States AB -We synthesize insights from current understanding of drought impacts at stand-to-biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand-level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, changes in composition and structure, and shifting range limits are widely observed. In the eastern US, the effects of increasing drought are becoming better understood at the level of individual trees, but this knowledge cannot yet be confidently translated to predictions of changing structure and diversity of forest stands. While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought. Throughout the continental United States, the combination of projected large climate-induced shifts in suitable habitat from modeling studies and limited potential for the rapid migration of tree populations suggests that changing tree and forest biogeography could substantially lag habitat shifts already underway. Forest management practices can partially ameliorate drought impacts through reductions in stand density, selection of drought-tolerant species and genotypes, artificial regeneration, and the development of multistructured stands. However, silvicultural treatments also could exacerbate drought impacts unless implemented with careful attention to site and stand characteristics. Gaps in our understanding should motivate new research on the effects of interactions involving climate and other species at the stand scale and how interactions and multiple responses are represented in models. This assessment indicates that, without a stronger empirical basis for drought impacts at the stand scale, more complex models may provide limited guidance.
VL - 22 SN - 1354-1013 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26898361&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 7 ER - TY - JOUR T1 - Long-term thinning alters ponderosa pine reproduction in northern Arizona. JF - Forest Ecology and Management Y1 - 2016 A1 - Flathers,KN A1 - TE Kolb A1 - Bradford,JB A1 - Waring,KM A1 - Moser,WK VL - 374 N1 - [Original String]:Flathers, K. N., Kolb, T. E., Bradford, J. B. Waring, K. M. and Moser, W. K. (2016). Long-term thinning alters ponderosa pine reproduction in northern Arizona. Forest Ecology and Management 374:154-165. ER - TY - JOUR T1 - Reference Conditions and Historical Fine-Scale Spatial Dynamics in a Dry Mixed-Conifer . JF - Forest Science Y1 - 2016 A1 - Rodman,KC A1 - Meador,AJS A1 - Huffman,DW A1 - Waring,KM VL - 62 N1 - [Original String]:Rodman, K. C. Meador, A. J. S., Huffman, D. W. and Waring, K. M. (2016). Reference Conditions and Historical Fine-Scale Spatial Dynamics in a Dry Mixed-Conifer Forest, Arizona, USA. Forest Science 62: 1-13. ER - TY - CONF T1 - Southwestern white pine seedling tolerances to a changing climate: early results from common gardens across an elevational gradient. T2 - Society of American Foresters National Convention Y1 - 2016 A1 - DaBell,J A1 - K Waring A1 - TE Kolb A1 - AV Whipple A1 - Madison,WI JF - Society of American Foresters National Convention T3 - Society of American Foresters National Convention CY - Madison, Wisconsin, USA VL - 2016 N1 - [Original String]:DaBell, J., Waring, K., Kolb, T., and Whipple, A. 2016. Southwestern white pine seedling tolerances to a changing climate: early results from common gardens across an elevational gradient. Society of American Foresters National Convention, November 2-5, 2016, Madison, WI. ER - TY - CONF T1 - Sustaining southwestern white pine by combining experimental work and genomic tools. Y1 - 2016 A1 - Castilla,AR A1 - R Sniezko A1 - K Waring A1 - Cushman,S A1 - Eckert,A.J A1 - Flores,L A1 - Still,C A1 - Wehenkel,C A1 - Whipple,A A1 - Wing,M A1 - TE Kolb A1 - Goodrich,B.A. ER -