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 - Plant-herbivore interactions in a trispecific hybrid swarm of Populus: assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity. JF - The New phytologist Y1 - 2016 A1 - Floate,Kevin D A1 - Godbout,Julie A1 - Lau,Matthew K A1 - Isabel,Nathalie A1 - Whitham,Thomas G KW - Alberta KW - Animals KW - Arthropods KW - biodiversity KW - Biological Evolution KW - Chimera KW - Ecosystem KW - Herbivory KW - Hybridization, Genetic KW - Populus KW - Trees KW - Utah AB -

Natural systems of hybridizing plants are powerful tools with which to assess evolutionary processes between parental species and their associated arthropods. Here we report on these processes in a trispecific hybrid swarm of Populus trees. Using field observations, common garden experiments and genetic markers, we tested the hypothesis that genetic similarities among hosts underlie the distributions of 10 species of gall-forming arthropods and their ability to adapt to new host genotypes.the degree of genetic relatedness among parental species determines whether hybridization is primarily bidirectional or unidirectional; host genotype and genetic similarity strongly affect the distributions of gall-forming species, individually and as a community. These effects were detected observationally in the wild and experimentally in common gardens; correlations between the diversity of host genotypes and their associated arthropods identify hybrid zones as centres of biodiversity and potential species interactions with important ecological and evolutionary consequences. These findings support both hybrid bridge and evolutionary novelty hypotheses. However, the lack of parallel genetic studies on gall-forming arthropods limits our ability to define the host of origin with their subsequent shift to other host species or their evolution on hybrids as their final destination.

VL - 209 SN - 0028-646X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26346922&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 2 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 - Genetic structure of a foundation species: scaling community phenotypes from the individual to the region. JF - Heredity Y1 - 2008 A1 - RK Bangert A1 - E V Lonsdorf A1 - Wimp,G M A1 - Shuster,S M A1 - Fischer,D A1 - Schweitzer,J A A1 - Allan,G J A1 - JK Bailey A1 - Whitham,T G KW - Animals KW - biodiversity KW - Ecosystem KW - Environment KW - Populus KW - Trees AB -

Understanding the local and regional patterns of species distributions has been a major goal of ecological and evolutionary research. The notion that these patterns can be understood through simple quantitative rules is attractive, but while numerous scaling laws exist (e.g., metabolic, fractals), we are aware of no studies that have placed individual traits and community structure together within a genetics based scaling framework. We document the potential for a genetic basis to the scaling of ecological communities, largely based upon our long-term studies of poplars (Populus spp.). The genetic structure and diversity of these foundation species affects riparian ecosystems and determines a much larger community of dependent organisms. Three examples illustrate these ideas. First, there is a strong genetic basis to phytochemistry and tree architecture (both above- and belowground), which can affect diverse organisms and ecosystem processes. Second, empirical studies in the wild show that the local patterns of genetics based community structure scale up to western North America. At multiple spatial scales the arthropod community phenotype is related to the genetic distance among plants that these arthropods depend upon for survival. Third, we suggest that the familiar species-area curve, in which species richness is a function of area, is also a function of genetic diversity. We find that arthropod species richness is closely correlated with the genetic marker diversity and trait variance suggesting a genetic component to these curves. Finally, we discuss how genetic variation can interact with environmental variation to affect community attributes across geographic scales along with conservation implications.

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=17047690&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 2 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 -