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.
Improved understanding of the effects of climate and weather patterns on plant survival and growth is critical for improving management of wildland, rangeland, and crop ecosystems. The Southwest Experimental Garden Array (SEGA) is a distributed research instrument comprising of an array of 10 common gardens across an elevational gradient in Northern Arizona. SEGA's cyber infrastructure facilitates monitoring and control of soil moisture at experimental plots using drip irrigation and wireless sensor/actuator nodes. This paper describes development of software-based workflows for the sensing and control of soil moisture conditions across experimental plots and gardens with different temperature and rainfall regimes, and the necessary hardware and software infrastructure to support this capability.
JF - 2017 IEEE Conference on Technologies for Sustainability (SusTech), PB - IEEE SusTech CY - Phoenix, AZ UR - https://ieeexplore.ieee.org/document/8333478/ ER - TY - JOUR T1 - B.A. Adams, and Plant genotype influences aquatic-terrestrial ecosystem linkages through timing and composition of insect emergence. JF - ECOSPHERE e01331 101002ecs21331 DOI 101002ecs21331 Y1 - 2016 A1 - Compson,ZG A1 - Hungate,TG A1 - Whitham,N A1 - Meneses,PE A1 - Busby,T A1 - Wojtowicz,AC A1 - Ford,KJ A1 - Marks,JC VL - 7 IS - 5 N1 - [Original String]:Compson, Z.G., B.A. Hungate, T.G. Whitham, N. Meneses, P.E. Busby, T. Wojtowicz, A.C. Ford, K.J. Adams, and Marks, J.C. 2016. Plant genotype influences aquatic-terrestrial ecosystem linkages through timing and composition of insect emergence. ECOSPHERE 7(5) : e01331. 10.1002/ecs2.1331. DOI: 10.1002/ecs2.1331 ER - TY - JOUR T1 - Genetic variation in NIN1 and C/VIF1 genes is significantly associated with Populus angustifolia resistance to a galling herbivore, Pemphigus betae. JF - Journal of insect physiology Y1 - 2016 A1 - Zinkgraf,Matthew S A1 - Meneses,Nashelly A1 - Whitham,Thomas G A1 - Allan,Gerard J KW - Animals KW - Aphids KW - beta-Fructofuranosidase KW - Enzyme Inhibitors KW - Genes, Plant KW - Genetic Variation KW - Haplotypes KW - Herbivory KW - Plant Immunity KW - Plant Proteins KW - Plant Tumors KW - Polymorphism, Single Nucleotide KW - Populus AB -The identification of genes associated with ecologically important traits provides information on the potential genetic mechanisms underlying the responses of an organism to its natural environment. In this study, we investigated the genetic basis of host plant resistance to the gall-inducing aphid, Pemphigus betae, in a natural population of 154 narrowleaf cottonwoods (Populus angustifolia). We surveyed genetic variation in two genes putatively involved in sink-source relations and a phenology gene that co-located in a previously identified quantitative trait locus for resistance to galling. Using a candidate gene approach, three major findings emerged. First, natural variation in tree resistance to galling was repeatable. Sampling of the same tree genotypes 20 years after the initial survey in 1986 show that 80% of the variation in resistance was due to genetic differences among individuals. Second, we identified significant associations at the single nucleotide polymorphism and haplotype levels between the plant neutral invertase gene NIN1 and tree resistance. Invertases are a class of sucrose hydrolyzing enzymes and play an important role in plant responses to biotic stress, including the establishment of nutrient sinks. These associations with NIN1 were driven by a single nucleotide polymorphism (NIN1_664) located in the second intron of the gene and in an orthologous sequence to two known regulatory elements. Third, haplotypes from an inhibitor of invertase (C/VIF1) were significantly associated with tree resistance. The identification of genetic variation in these two genes provides a starting point to understand the possible genetic mechanisms that contribute to tree resistance to gall formation. We also build on previous work demonstrating that genetic differences in sink-source relationships of the host influence the ability of P. betae to manipulate the flow of nutrients and induce a nutrient sink.
VL - 84 SN - 0022-1910 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26518288&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. ER - TY - JOUR T1 - Genetically informed ecological niche models improve climate change predictions JF - Global Change Biology Y1 - 2016 A1 - DH Ikeda A1 - Max,TL A1 - GJ Allan A1 - Lau,MK A1 - SM Shuster A1 - TG Whitham 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 - Local-Scale Drought Adaptation of Ponderosa Pine Seedlings at Habitat Ecotones JF - Forest Science Y1 - 2016 A1 - TE Kolb A1 - Grady,KC A1 - Mcettrick,MP A1 - Herrero,A AB - Abstract Understanding the magnitude and pattern of intraspecific variation in tree adaptation to drought is needed to evaluate forest capacity to respond to climate change and for management planning. This understanding is important for species growing at ecotonal sites near the trailing edge of their geographic range where impacts of climate warming are predicted to be most severe. We used a greenhouse common garden to investigate phenotypic variations in growth, drought-adaptive structural traits (e.g., wood specific gravity, shoot-root ratio, and specific leaf area), and survival during experimental drought in seedlings of ponderosa pine (Pinus ponderosa Doug. Ex. Laws) sampled from 17 sites in northern Arizona over gradients of elevation, precipitation, and soil parent material. Phenotypic variation was significant in most seedling traits, and the most variation occurred among maternal families within site populations. Growth rate was negatively correlated with wood specific gravity. The large amount of phenotypic variation within populations suggests the potential for future evolution of stress tolerance in trailing-edge populations. The strongest geographic pattern in phenotypic variation was a negative relationship between seedling biomass allocation to roots and precipitation of the population site. Families with the longest survival in a lethal drought experiment tended to come from low-elevation, drier sites. VL - 62 UR - http://www.ingentaconnect.com/content/saf/fs/pre-prints/content-forsci16049 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 - Phylogenetic organization of bacterial activity. JF - The ISME journal Y1 - 2016 A1 - Ember M Morrissey A1 - Mau,Rebecca L A1 - Egbert Schwartz A1 - Caporaso,J Gregory A1 - P Dijkstra A1 - van Gestel,Natasja A1 - BJ Koch A1 - Liu,Cindy M A1 - Hayer,Michaela A1 - McHugh,Theresa A A1 - Jane C Marks A1 - Lance B Price A1 - Hungate,Bruce A KW - Bacteria KW - Biological Evolution KW - Carbon Isotopes KW - Ecology KW - Ecosystem KW - Oxygen Isotopes KW - Phenotype KW - Phylogeny AB -Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more common to microbes such as gene loss and lateral gene transfer, as well as convergent evolution. Here we use advanced stable isotope probing with (13)C and (18)O to show that evolutionary history has ecological significance for in situ bacterial activity. Phylogenetic organization in the activity of bacteria sets the stage for characterizing the functional attributes of bacterial taxonomic groups. Connecting identity with function in this way will allow scientists to begin building a mechanistic understanding of how bacterial community composition regulates critical ecosystem functions.
VL - 10 SN - 1751-7362 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26943624&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 9 ER - TY - JOUR T1 - Prestoration: Using species in restoration that will persist now and into the future. JF - Restoration Ecology Y1 - 2016 A1 - Butterfield,BJ A1 - Copeland,SM A1 - Munson,SM A1 - Roybal,CM A1 - Wood,TE AB -Climate change presents newchallenges for selecting species for restoration. If migration fails to keep pace with climate change, as models predict, the most suitable sources for restoration may not occur locally at all. To address this issue, we propose a strategy of “prestoration”: utilizing species in restoration for which a site represents suitable habitat now and into the future. Using the Colorado Plateau, United States, as a case study, we assess the ability of grass species currently used regionally in restoration to persist into the future using projections of ecological niche models (or climate envelope models) across a suite of climate change scenarios. We then present a technique for identifying new species that best compensate for future losses of suitable habitat by current target species. We found that the current suite of species, selected by a group of experts, is predicted to perform reasonably well in the short term, but that losses of prestorable habitat by mid-century would approach 40%. Using an algorithm to identify additional species, we found that fewer than 10 species could compensate for nearly all of the losses incurred by the current target species. This case study highlights the utility of integrating ecological niche modeling and future climate forecasts to predict the utility of species in restoring under climate change across a wide range of spatial and temporal scales.
N1 - [Original String]:Butterfield, B.J., Copeland, S.M., Munson, S.M., Roybal, C.M. and Wood, T.E. (In press). Prestoration: Using species in restoration that will persist now and into the future. Restoration Ecology. 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 - Taxon-specific microbial activities explain soil carbon cycling dynamics. T2 - Ecological Society of America Y1 - 2016 A1 - Morrissey,EM A1 - RL Mau A1 - Schwartz,E A1 - Caporaso,JG A1 - P Dijkstra A1 - McHugh,T A1 - Marks,JC A1 - Price,LB A1 - Liu,CM A1 - Hungate,BA AB -Morrissey, E.M., Mau, R.L., Schwartz, E., Caporaso, J.G., Dijkstra, P.,McHugh, T., Marks, J.C., Price, L.B., Liu, C.M. and Hungate, B.A. (2016). Taxon-specific microbial activities explain soil carbon cycling dynamics. ESA August 7-12, Fort Lauderdale.
JF - Ecological Society of America T3 - Ecological Society of America Annual Meeting PB - ESA CY - Fort Lauderdale, Florida, USA N1 - [Original String]:Morrissey, E.M., Mau, R.L., Schwartz, E., Caporaso, J.G., Dijkstra, P., McHugh, T., Marks, J.C., Price, L.B., Liu, C.M. and Hungate, B.A. (2016). Taxon-specific microbial activities explain soil carbon cycling dynamics. ESA August 7-12, Fort Lauderdale. ER - TY - CONF T1 - Taxon-Specific Responses To Whole System Carbon Cycling In The Root Microbiome. T2 - Phytobiomes from microbes to plant ecosystems Y1 - 2016 A1 - P Dijkstra A1 - RL Mau A1 - McHugh,TA A1 - BJ Koch A1 - Marks,JC A1 - van Groenigen,K-J A1 - Liu,X-J A1 - Schwartz,E A1 - Morrissey,EM A1 - Hungate,BA AB -Dijkstra, P., Mau, R.L., McHugh, T.A., Koch, B.J., Marks, J.C., vanGroenigen, K-J., Liu, X-J. A., Schwartz, E., Morrissey, E.M. and Hungate, B.A. (2016). From Taxon-Specific Responses To Whole System Carbon Cycling In The Root Microbiome. Phytobiomes: from microbes to plant ecosystems. Nov 2016, .
JF - Phytobiomes from microbes to plant ecosystems T3 - Phytobiomes from microbes to plant ecosystems CY - Santa Fe, New Mexicao, USA N1 - [Original String]:Dijkstra, P., Mau, R.L., McHugh, T.A., Koch, B.J., Marks, J.C., van Groenigen, K-J., Liu, X-J. A., Schwartz, E., Morrissey, E.M. and Hungate, B.A. (2016). From Taxon-Specific Responses To Whole System Carbon Cycling In The Root Microbiome. Phytobiomes: from microbes to plant ecosystems. Nov 2016, Santa Fe NM. ER - TY - JOUR T1 - Temperature is better than precipitation as a predictor of plant community assembly across a dryland region. JF - Journal of Vegetation Science Y1 - 2016 A1 - Butterfield,BJ A1 - Munson,SM AB -How closely do plant communities track climate? Research suggests that plant species converge toward similar environmental tolerances relative to the environments that they experience. Whether these patterns apply to severe environments or scale up to plant community-level patterns of relative climatic tolerances is poorly understood. Using estimates of species' climatic tolerances acquired from occurrence records, we determined the contributions of individual species' climatic niche breadths and environmental filtering to the relationships between community-average climatic tolerances and the local climates experienced by those communities.
Southwestern United States drylands.
Interspecific variation in niche breadth was assessed as a function of species' climatic optima (median climatic niche value). The relationships between climatic optima and tolerances were used as null expectations for the relationship between abundance-weighted mean climatic tolerances of communities and the local climate of that community. Deviations from this null expectation indicate that species with greater or lesser climatic tolerances are favoured relative to co-occurring species. The intensity of environmental filtering was estimated by comparing the range of climatic tolerances within each community to a null distribution generated from a random assembly algorithm.
The temperature niches of species were consistently symmetrical and of similar breadths, regardless of their temperature optima. In contrast, precipitation niches were skewed toward wetter conditions, and niche breadth increased with increasing precipitation optima. At the community level, relationships with climate were much stronger for temperature than for precipitation. Furthermore, cold and heat were stronger assembly filters than drought or precipitation, with the intensity of environmental filtering increasing at both ends of climatic gradients. Community-average climatic tolerances did deviate significantly from null expectations, indicating that species with higher or lower relative climatic tolerances were favoured under certain conditions.
Despite strong water limitation of plant performance in dryland ecosystems, communities tracked variation in temperature much more closely, intimating strong responses to anticipated temperature increases. Furthermore, abundance distributions were biased toward species with higher or lower relative climatic tolerances under different climatic conditions, but predictably so, indicating the need for assembly models that include processes other than simple environmental filtering.
VL - 27 IS - 5 N1 - [Original String]:Butterfield, B.J. and Munson, S.M. (In press). Temperature is better than precipitation as a predictor of plant community assembly across a dryland region. Journal of Vegetation Science. ER - TY - JOUR T1 - Dynamics of extracellular DNA decomposition and bacterial community composition in soil. JF - Soil Biology and Biochemistry Y1 - 2015 A1 - Morrissey,EM A1 - McHugh,TA A1 - Preteska,L A1 - Hayer,M A1 - P Dijkstra A1 - Hungate,BA A1 - Schwartz,E VL - 86 N1 - [Original String]:Morrissey, E.M., McHugh, T.A., Preteska, L., Hayer, M., Dijkstra, P., Hungate, B.A., and Schwartz E (2015). Dynamics of extracellular DNA decomposition and bacterial community composition in soil. Soil Biology and Biochemistry 86, 42-49. ER - TY - JOUR T1 - High carbon use efficiency in soil microbial communities is related to growth, not storage compound synthesis. JF - Soil Biology and Biochemistry Y1 - 2015 A1 - P Dijkstra A1 - Salpas,E A1 - Fairbanks,D A1 - Miller,EB A1 - Hagerty,SB A1 - KJ van Groenigen A1 - Hungate,BA A1 - Marks,JC A1 - GW Koch A1 - Schwartz,E VL - 89 N1 - [Original String]:Dijkstra, P., Salpas, E., Fairbanks, D., Miller EB, Hagerty, S.B., van Groenigen, K.J., Hungate, B.A., Marks, J.C., Koch, G.W., and Schwartz, E. (2015). High carbon use efficiency in soil microbial communities is related to growth, not storage compound synthesis. Soil Biology and Biochemistry 89, 35-43. ER - TY - JOUR T1 - Linking soil bacterial biodiversity and soil carbon stability. JF - The ISME journal Y1 - 2015 A1 - Mau,Rebecca L A1 - Liu,Cindy M A1 - Aziz,Maliha A1 - Egbert Schwartz A1 - P Dijkstra A1 - Jane C Marks A1 - Lance B Price A1 - Keim,Paul A1 - Hungate,Bruce A KW - Bacteria KW - biodiversity KW - Biomass KW - Carbon KW - Ecosystem KW - Glucose KW - Isotopes KW - Oxygen KW - RNA, Ribosomal, 16S KW - Soil KW - Soil Microbiology AB -Native soil carbon (C) can be lost in response to fresh C inputs, a phenomenon observed for decades yet still not understood. Using dual-stable isotope probing, we show that changes in the diversity and composition of two functional bacterial groups occur with this 'priming' effect. A single-substrate pulse suppressed native soil C loss and reduced bacterial diversity, whereas repeated substrate pulses stimulated native soil C loss and increased diversity. Increased diversity after repeated C amendments contrasts with resource competition theory, and may be explained by increased predation as evidenced by a decrease in bacterial 16S rRNA gene copies. Our results suggest that biodiversity and composition of the soil microbial community change in concert with its functioning, with consequences for native soil C stability.
VL - 9 SN - 1751-7362 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=25350158&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 6 ER - TY - JOUR T1 - Leaf litter quality affects aquatic insect emergence: contrasting patterns from two foundation trees. JF - Oecologia Y1 - 2013 A1 - Compson,Zacchaeus G A1 - Adams,Kenneth J A1 - Edwards,Joeseph A A1 - Maestas,Jesse M A1 - Whitham,Thomas G A1 - Jane C Marks KW - Animals KW - arizona KW - Biota KW - Food Chain KW - Insecta KW - Plant Leaves KW - Populus KW - Rivers KW - Species Specificity AB -Reciprocal subsidies between rivers and terrestrial habitats are common where terrestrial leaf litter provides energy to aquatic invertebrates while emerging aquatic insects provide energy to terrestrial predators (e.g., birds, lizards, spiders). We examined how aquatic insect emergence changed seasonally with litter from two foundation riparian trees, whose litter often dominates riparian streams of the southwestern United States: Fremont (Populus fremontii) and narrowleaf (Populus angustifolia) cottonwood. P. fremontii litter is fast-decomposing and lower in defensive phytochemicals (i.e., condensed tannins, lignin) relative to P. angustifolia. We experimentally manipulated leaf litter from these two species by placing them in leaf enclosures with emergence traps attached in order to determine how leaf type influenced insect emergence. Contrary to our initial predictions, we found that packs with slow-decomposing leaves tended to support more emergent insects relative to packs with fast-decomposing leaves. Three findings emerged. Firstly, abundance (number of emerging insects m(-2) day(-1)) was 25% higher on narrowleaf compared to Fremont leaves for the spring but did not differ in the fall, demonstrating that leaf quality from two dominant trees of the same genus yielded different emergence patterns and that these patterns changed seasonally. Secondly, functional feeding groups of emerging insects differed between treatments and seasons. Specifically, in the spring collector-gatherer abundance and biomass were higher on narrowleaf leaves, whereas collector-filterer abundance and biomass were higher on Fremont leaves. Shredder abundance and biomass were higher on narrowleaf leaves in the fall. Thirdly, diversity (Shannon's H') was higher on Fremont leaves in the spring, but no differences were found in the fall, showing that fast-decomposing leaves can support a more diverse, complex emergent insect assemblage during certain times of the year. Collectively, these results challenge the notion that leaf quality is a simple function of decomposition, suggesting instead that aquatic insects benefit differentially from different leaf types, such that some use slow-decomposing litter for habitat and its temporal longevity and others utilize fast-decomposing litter with more immediate nutrient release.
VL - 173 SN - 0029-8549 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=23532583&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 2 ER - TY - JOUR T1 - Phenotypic variation in nurse traits and community feedbacks define an alpine community. JF - Ecology letters Y1 - 2011 A1 - Michalet,Richard A1 - Xiao,Sa A1 - Touzard,Blaise A1 - David S Smith A1 - Cavieres,Lohengrin A A1 - Callaway,Ragan M A1 - Whitham,Thomas G KW - arizona KW - Ecosystem KW - Genotype KW - Geum KW - Models, Biological KW - Phenotype KW - Plant Leaves KW - Plant Roots KW - Plant Stems KW - Population Dynamics KW - Selection, Genetic AB -Much is known about facilitation, but virtually nothing about the underlying genetic and evolutionary consequences of this important interaction. We assessed the potential of phenotypic differences in facilitative effects of a foundation species to determine the composition of an Alpine community in Arizona. Two phenotypes of Geum rossii occur along a gradient of disturbance, with 'tight' competitive cushions in stable conditions and 'loose' facilitative cushions in disturbed conditions. A common-garden study suggested that field-based traits may have a genetic basis. Field experiments showed that the reproductive fitness of G. rossii cushions decreased with increasing facilitation. Finally, using a dual-lattice model we showed that including the cost and benefit of facilitation may contribute to the co-occurrence of genotypes with contrasting facilitative effects. Our results indicate that changes in community composition due to phenotypic differences in facilitative effects of a foundation species may in turn affect selective pressures on the foundation species.
VL - 14 SN - 1461-023X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=21366815&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 5 ER - TY - JOUR T1 - From genes to ecosystems: a synthesis of the effects of plant genetic factors across levels of organization. JF - Philosophical transactions of the Royal Society of London. Series B, Biological sciences Y1 - 2009 A1 - JK Bailey A1 - Jennifer A Schweitzer A1 - Ubeda,Francisco A1 - Koricheva,Julia A1 - LeRoy,Carri J A1 - Madritch,Michael D A1 - Rehill,Brian J A1 - RK Bangert A1 - Fischer,Dylan G A1 - Allan,Gerard J A1 - Whitham,Thomas G KW - Animals KW - Arthropods KW - Ecosystem KW - Genetic Variation KW - Genetics, Population KW - Models, Genetic KW - Plant Development KW - Plants AB -Using two genetic approaches and seven different plant systems, we present findings from a meta-analysis examining the strength of the effects of plant genetic introgression and genotypic diversity across individual, community and ecosystem levels with the goal of synthesizing the patterns to date. We found that (i) the strength of plant genetic effects can be quite high; however, the overall strength of genetic effects on most response variables declined as the levels of organization increased. (ii) Plant genetic effects varied such that introgression had a greater impact on individual phenotypes than extended effects on arthropods or microbes/fungi. By contrast, the greatest effects of genotypic diversity were on arthropods. (iii) Plant genetic effects were greater on above-ground versus below-ground processes, but there was no difference between terrestrial and aquatic environments. (iv) The strength of the effects of intraspecific genotypic diversity tended to be weaker than interspecific genetic introgression. (v) Although genetic effects generally decline across levels of organization, in some cases they do not, suggesting that specific organisms and/or processes may respond more than others to underlying genetic variation. Because patterns in the overall impacts of introgression and genotypic diversity were generally consistent across diverse study systems and consistent with theoretical expectations, these results provide generality for understanding the extended consequences of plant genetic variation across levels of organization, with evolutionary implications.
VL - 364 SN - 0962-8436 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=19414474&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1523 ER - TY - JOUR T1 - Genetic and environmental controls of microbial communities on leaf litter in streams . JF - Freshwater Biology Y1 - 2009 A1 - Marks,JC A1 - Haden,GA A1 - Harrop,BA A1 - Reese,EG A1 - Keams,JL A1 - Watwood,ME A1 - TG Whitham VL - 54 N1 - [Original String]:Marks JC, Haden GA, Harrop BA, Reese EG, Keams JL, Watwood ME, Whitham TG. 2009. Genetic and environmental controls of microbial communities on leaf litter in streams . Freshwater Biology 54:2616-2627. ER - TY - JOUR T1 - A dense linkage map of hybrid cottonwood (Populus fremontii x P. angustifolia) contributes to long-term ecological research and comparison mapping in a model forest tree. JF - Heredity Y1 - 2008 A1 - Woolbright,S A A1 - Difazio,S P A1 - Yin,T A1 - Martinsen,G D A1 - Zhang,X A1 - Allan,G J A1 - Whitham,T G A1 - Keim,P KW - Chimera KW - Chromosome Mapping KW - Ecology KW - Genetic Linkage KW - Genetic Markers KW - Genetics, Population KW - Genome, Plant KW - Linkage Disequilibrium KW - Models, Biological KW - Polymorphism, Restriction Fragment Length KW - Populus KW - Trees AB -Cottonwoods are foundation riparian species, and hybridization among species is known to produce ecological effects at levels higher than the population, including effects on dependent species, communities and ecosystems. Because these patterns result from increased genetic variation in key cottonwood traits, novel applications of genetic tools (for example, QTL mapping) could be used to place broad-scale ecological research into a genomic perspective. In addition, linkage maps have been produced for numerous species within the genus, and, coupled with the recent publication of the Populus genome sequence, these maps present a unique opportunity for genome comparisons in a model system. Here, we conducted linkage analyses in order to (1) create a platform for QTL and candidate gene studies of ecologically important traits, (2) create a framework for chromosomal-scale perspectives of introgression in a natural population, and (3) enhance genome-wide comparisons using two previously unmapped species. We produced 246 backcross mapping (BC(1)) progeny by crossing a naturally occurring F(1) hybrid (Populus fremontii x P. angustifolia) to a pure P. angustifolia from the same population. Linkage analysis resulted in a dense linkage map of 541 AFLP and 111 SSR markers distributed across 19 linkage groups. These results compared favorably with other Populus linkage studies, and addition of SSR loci from the poplar genome project provided coarse alignment with the genome sequence. Preliminary applications of the data suggest that our map represents a useful framework for applying genomic research to ecological questions in a well-studied system, and has enhanced genome-wide comparisons in a model tree.
VL - 100 SN - 0018-067X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17895905&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1 ER - TY - JOUR T1 - From genes to ecosystems: the genetic basis of condensed tannins and their role in nutrient regulation in a Populus model system . JF - Ecosystems Y1 - 2008 A1 - Schweitzer,JA A1 - Madritch,MD A1 - JK Bailey A1 - LeRoy,CJ A1 - Fischer,DG A1 - Rehill,BJ A1 - Lindroth,RL A1 - Hagerman,AE A1 - Wooley,SC A1 - Hart,SC A1 - TG Whitham VL - 11 N1 - [Original String]:Schweitzer JA, Madritch MD, Bailey JK, LeRoy CJ, Fischer DG, Rehill BJ, Lindroth RL, Hagerman AE, Wooley SC, Hart SC, Whitham TG. 2008. From genes to ecosystems: the genetic basis of condensed tannins and their role in nutrient regulation in a Populus model system . Ecosystems 11:1005-1020. ER - TY - JOUR T1 - Plant genetics predicts intra-annual variation in phytochemistry and arthropod community structure. JF - Molecular ecology Y1 - 2007 A1 - Wimp,G M A1 - Wooley,S A1 - RK Bangert A1 - Young,W P A1 - Martinsen,G D A1 - Keim,P A1 - Rehill,B A1 - R L Lindroth A1 - Whitham,T G KW - Animals KW - Arthropods KW - DNA, Plant KW - Ecosystem KW - Genetics, Population KW - Plant Extracts KW - Polymorphism, Restriction Fragment Length KW - Population Density KW - Population Dynamics KW - Populus KW - Seasons AB -With the emerging field of community genetics, it is important to quantify the key mechanisms that link genetics and community structure. We studied cottonwoods in common gardens and in natural stands and examined the potential for plant chemistry to be a primary mechanism linking plant genetics and arthropod communities. If plant chemistry drives the relationship between plant genetics and arthropod community structure, then several predictions followed. We would find (i) the strongest correlation between plant genetic composition and chemical composition; (ii) an intermediate correlation between plant chemical composition and arthropod community composition; and (iii) the weakest relationship between plant genetic composition and arthropod community composition. Our results supported our first prediction: plant genetics and chemistry had the strongest correlation in the common garden and the wild. Our results largely supported our second prediction, but varied across space, seasonally, and according to arthropod feeding group. Plant chemistry played a larger role in structuring common garden arthropod communities relative to wild communities, free-living arthropods relative to leaf and stem modifiers, and early-season relative to late-season arthropods. Our results did not support our last prediction, as host plant genetics was at least as tightly linked to arthropod community structure as plant chemistry, if not more so. Our results demonstrate the consistency of the relationship between plant genetics and biodiversity. Additionally, plant chemistry can be an important mechanism by which plant genetics affects arthropod community composition, but other genetic-based factors are likely involved that remain to be measured.
VL - 16 SN - 0962-1083 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17927708&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 23 ER - TY - JOUR T1 - Within-species variation in foliar chemistry influences leaf-litter decomposition in a Utah river . JF - Journal of The North American Benthological Society Y1 - 2007 A1 - LeRoy,CJ A1 - TG Whitham A1 - Wooley,SC A1 - Marks,JC VL - 26 IS - 3 N1 - [Original String]:LeRoy CJ, Whitham TG, Wooley SC, Marks JC. 2007. Within-species variation in foliar chemistry influences leaf-litter decomposition in a Utah river . Journal of The North American Benthological Society 26(3):426-438. ER - TY - JOUR T1 - Developmental trajectories in cottonwood phytochemistry. JF - Journal of chemical ecology Y1 - 2006 A1 - Rehill,Brian J A1 - Whitham,Thomas G A1 - Martinsen,Gregory D A1 - Jennifer A Schweitzer A1 - JK Bailey A1 - Lindroth,Richard L KW - Crosses, Genetic KW - Glucosides KW - Least-Squares Analysis KW - Nitrogen KW - Phenols KW - Populus KW - Proanthocyanidins AB -We examined the hypothesis that ecologically important phytochemical traits differ predictably among various developmental zones of trees (i.e., mature and juvenile zones of individual trees and juvenile ramets that sprout from roots) and that the slope of this phytochemical gradient represents a "developmental trajectory." We focused on Populus fremontii (Fremont cottonwood), P. angustifolia (narrowleaf cottonwood), and their natural hybrids. Two major patterns emerged. First, within narrowleaf and hybrids, concentrations of important phytochemicals (condensed tannins and phenolic glycosides) differ greatly and predictably between developmental zones. Second, developmental trajectories differ greatly among these cottonwood species and their hybrids: Fremont exhibits a flat trajectory, narrowleaf a steep trajectory, and hybrids an intermediate trajectory, suggesting an additive genetic component and an ontogenetic basis to this phytochemical variation. Because diverse herbivorous species respond to the phytochemistry of their host plants, we predict that the developmental trajectories of plants play a major role in mediating ecological interactions and structuring communities, and that biodiversity in a stand of trees is determined by both interplant genetic diversity and intraplant ontogenetic diversity.
VL - 32 SN - 0098-0331 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17001533&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 10 ER - TY - JOUR T1 - Environmental and genetic effects on the formation of ectomycorrhizal and arbuscular mycorrhizal associations in cottonwoods. JF - Oecologia Y1 - 2006 A1 - Gehring,Catherine A A1 - Mueller,Rebecca C A1 - Whitham,Thomas G KW - Altitude KW - Carbon KW - Hybridization, Genetic KW - Mycorrhizae KW - Nitrogen KW - Polymorphism, Restriction Fragment Length KW - Populus KW - Soil KW - Symbiosis KW - Utah KW - Water AB -Although both environment and genetics have been shown to affect the mycorrhizal colonization of host plants, the impacts of these factors on hosts that can be dually colonized by both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi are less understood. We examined the influence of environment and host crosstype on the EM and AM colonization of cottonwoods (Populus angustifolia and natural hybrids) by comparing levels of colonization of trees growing in common gardens that differed in elevation and soil type. We also conducted a supplemental watering experiment to determine the influence of soil moisture on AM and EM colonization. Three patterns emerged. First, garden location had a significant impact on mycorrhizal colonization, such that EM colonization was 30% higher and AM colonization was 85% lower in the higher elevation garden than the lower elevation garden. Second, crosstype affected total (EM + AM) colonization, but did not affect EM or AM colonization. Similarly, a significant garden x crosstype interaction was found for total colonization, but not for EM or AM colonization. Third, experimental watering resulted in 33% higher EM colonization and 45% lower AM colonization, demonstrating that soil moisture was a major driver of the mycorrhizal differences observed between the gardens. We conclude that environment, particularly soil moisture, has a larger influence on colonization by AM versus EM fungi than host genetics, and suggest that environmental stress may be a major determinant of mycorrhizal colonization in dually colonized host plants.
VL - 149 SN - 0029-8549 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=16642319&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1 ER - TY - JOUR T1 - A framework for community and ecosystem genetics: from genes to ecosystems. JF - Nature reviews. Genetics Y1 - 2006 A1 - Whitham,Thomas G A1 - JK Bailey A1 - Jennifer A Schweitzer A1 - Shuster,Stephen M A1 - RK Bangert A1 - LeRoy,Carri J A1 - Lonsdorf,Eric V A1 - Allan,Gery J A1 - DiFazio,Stephen P A1 - Potts,Brad M A1 - Fischer,Dylan G A1 - Gehring,Catherine A A1 - Lindroth,Richard L A1 - Jane C Marks A1 - Stephen C Hart A1 - Wimp,Gina M A1 - Wooley,Stuart C KW - Animals KW - Ecosystem KW - Genetics, Population KW - Humans KW - Plants AB -Can heritable traits in a single species affect an entire ecosystem? Recent studies show that such traits in a common tree have predictable effects on community structure and ecosystem processes. Because these 'community and ecosystem phenotypes' have a genetic basis and are heritable, we can begin to apply the principles of population and quantitative genetics to place the study of complex communities and ecosystems within an evolutionary framework. This framework could allow us to understand, for the first time, the genetic basis of ecosystem processes, and the effect of such phenomena as climate change and introduced transgenic organisms on entire communities.
VL - 7 SN - 1471-0056 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=16778835&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 7 ER - TY - JOUR T1 - From genes to geography: a genetic similarity rule for arthropod community structure at multiple geographic scales. JF - Molecular ecology Y1 - 2006 A1 - RK Bangert A1 - Allan,G J A1 - Turek,R J A1 - Wimp,G M A1 - Meneses,N A1 - Martinsen,G D A1 - Keim,P A1 - Whitham,T G KW - Animals KW - Arthropods KW - biodiversity KW - Genetic Variation KW - Genetics, Population KW - Models, Genetic KW - Populus KW - Rivers KW - Southwestern United States AB -We tested the hypothesis that leaf modifying arthropod communities are correlated with cottonwood host plant genetic variation from local to regional scales. Although recent studies found that host plant genetic composition can structure local dependent herbivore communities, the abiotic environment is a stronger factor than the genetic effect at increasingly larger spatial scales. In contrast to these studies we found that dependent arthropod community structure is correlated with both the cross type composition of cottonwoods and individual genotypes within local rivers up to the regional scale of 720,000 km(2) (Four Corner States region in the southwestern USA). Across this geographical extent comprising two naturally hybridizing cottonwood systems, the arthropod community follows a simple genetic similarity rule: genetically similar trees support more similar arthropod communities than trees that are genetically dissimilar. This relationship can be quantified with or without genetic data in Populus.
VL - 15 SN - 0962-1083 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17054514&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 13 ER -