Browsing by Author "Rice, Karen E"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Is it getting hot in here? Adjustment of hydraulic parameters in six boreal and temperate tree species after 5 years of warming
    (Wiley, 2016) Mculloh, Katherine A; Petitmermet, Joshua; Stefanski, Artur; Rice, Karen E; Rich, Roy L.; Montgomery, Rebecca A; Reich, Peter B
    Global temperatures (T) are rising, and for many plant species, their physiological response to this change has not been well characterized. In particular, how hydraulic parameters may change has only been examined experimentally for a few species. To address this, we measured characteristics of the hydraulic architecture of six species growing in ambient T and ambient +3.4 °C T plots in two experimentally warmed forest sites in Minnesota. These sites are at the temperate–boreal ecotone, and we measured three species from each forest type. We hypothesized that relative to boreal species, temperate species near their northern range border would increase xylem conduit diameters when grown under elevated T. We also predicted a continuum of responses among wood types, with conduit diameter increases correlating with increases in the complexity of wood structure. Finally, we predicted that increases in conduit diameter and specific hydraulic conductivity would positively affect photosynthetic rates and growth. Our results generally supported our hypotheses, and conduit diameter increased under elevated T across all species, although this pattern was driven predominantly by three species. Two of these species were temperate angiosperms, but one was a boreal conifer, contrary to predictions. We observed positive relationships between the change in specific hydraulic conductivity and both photosynthetic rate (P = 0.080) and growth (P = 0.012). Our results indicate that species differ in their ability to adjust hydraulically to increases in T. Specifically, species with more complex xylem anatomy, particularly those individuals growing near the cooler edge of their range, appeared to be better able to increase conduit diameters and specific hydraulic conductivity, which permitted increases in photosynthesis and growth. Our data support results that indicate individual's ability to physiologically adjust is related to their location within their species range, and highlight that some wood types may adjust more easily than others.
  • Thumbnail Image
    Item
    Phenological data (2009-2013) for ten tree species grown under experimental warming in northern Minnesota, USA
    (2020-03-27) Montgomery, Rebecca A; Stefanski, Artur; Reich, Peter B; Rice, Karen E; rebeccam@umn.edu; Montgomery, Rebecca A; University of Minnesota Forest Ecology Group
    This dataset contains five years of data on time of budburst, growing degree days at the time of budburst, time of senescence and phenological growing season length phenology data for ten tree species native to Minnesota, USA. Data were collected in a long-term open-air warming experiment located a the Cloquet Forestry Center, Cloquet, MN, USA and the Hubachek Wilderness Research Center, Ely, MN, USA. The design was a 2 (site) X 2 (habitat) x 3 (warming treatment) factorial, with 6 replicates (2 per block) for a total of 72 7.1 m2 circular plots. Species include: Quercus rubra, Quercus macrocarpa, Pinus banksiana, Pinus strobus, Populus tremuloides, Betula papyrifera, Abies balsamea, Picea glauca, Acer rubrum, Acer saccharum. These data are released in conjunction with a publication.