Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
9
result(s) for
"Great Basin bristlecone pine."
Sort by:
Bristlecone pines are ancient!
This book draws readers into the ancient world through the life cycle of the bristlecone pine tree.
Book
Defense traits in the long-lived Great Basin bristlecone pine and resistance to the native herbivore mountain pine beetle
Mountain pine beetle (MPB, Dendroctonus ponderosae) is a significant mortality agent of Pinus, and climate-driven range expansion is occurring. Pinus defenses in recently invaded areas, including high elevations, are predicted to be lower than in areas with longer term MPB presence. MPB was recently observed in high-elevation forests of the Great Basin (GB) region, North America. Defense and susceptibility in two long-lived species, GB bristlecone pine (Pinus longaeva) and foxtail pine (P. balfouriana), are unclear, although they are sympatric with a common MPB host, limber pine (P. flexilis).
We surveyed stands with sympatric GB bristlecone–limber pine and foxtail–limber pine to determine relative MPB attack susceptibility and constitutive defenses.
MPB-caused mortality was extensive in limber, low in foxtail and absent in GB bristlecone pine. Defense traits, including constitutive monoterpenes, resin ducts and wood density, were higher in GB bristlecone and foxtail than in limber pine.
GB bristlecone and foxtail pines have relatively high levels of constitutive defenses which make them less vulnerable to climate-driven MPB range expansion relative to other highelevation pines. Long-term selective herbivore pressure and exaptation of traits for tree longevity are potential explanations, highlighting the complexity of predicting plant–insect interactions under climate change.
Journal Article
Post-Wildfire Regeneration in a Sky-Island Mixed- Conifer Ecosystem of the North American Great Basin
Information on wildfire impacts and ecosystem responses is relatively sparse in the Great Basin of North America, where subalpine ecosystems are generally dominated by five-needle pines. We analyzed existing vegetation, with an emphasis on regeneration following the year 2000 Phillips Ranch Fire, at a sky-island site in the Snake Range of eastern Nevada. Our main objective was to compare bristlecone pine (Pinus longaeva; PILO) post-fire establishment and survival to that of the co-occurring dominant conifers limber pine (Pinus flexilis; PIFL) and Engelmann spruce (Picea engelmannii; PIEN) in connection with site characteristics. Field data were collected in 40 circular 0.1 ha plots (17.8 m radius) randomly located using GIS so that half of them were inside (“burned”) and half were outside (“unburned”) the 2000 fire boundary. While evidence of previous burns was also found, we focused on impacts from the Phillips Ranch Fire. Mean total basal area, including live and dead stems, was not significantly different between plots inside the burn and plots outside the fire perimeter, but the live basal area was significantly less in the former than in the latter. Wildfire impacts did not limit regeneration, and indeed bristlecone seedlings and saplings were more abundant in plots inside the 2000 fire perimeter than in those outside of it. PILO regeneration, especially saplings, was more abundant than PIFL and PCEN combined, indicating that PILO can competitively regenerate under modern climatic conditions. Surviving PILO regeneration in burned plots was also taller than that of PIFL. By contrast, PCEN was nearly absent in the plots that had been impacted by fire. Additional research should explicitly address how climatic changes and disturbance processes may interact in shaping future vegetation dynamics.
Journal Article
Soil Preferences in Germination and Survival of Limber Pine in the Great Basin White Mountains
In the Great Basin, limber pine is a sub-alpine tree species that is colonizing newly available habitat above treeline in greater numbers than treeline-dominating Great Basin bristlecone pine, especially on dolomite soil, where few plants are able to grow and where limber pine adults are rare. To examine the role of soil type on germination and establishment of limber pine, I sowed limber pine seeds in containers of the three main White Mountains soil types in one location while measuring soil moisture and temperature. I found that dolomite soil retains water longer, and has higher soil water content, than quartzite and granite soils and has the coolest maximum growing season temperatures. Limber pine germination and survival were highest in dolomite soil relative to quartzite and granite where limber pine adults are more common. While adult limber pines are rare on dolomite soils, young limber pines appear to prefer them. This indicates that limber pine either has only recently been able to survive in treeline climate on dolomite or that bristlecone pine has some long-term competitive advantage on dolomite making limber pine, a species with 1500 year old individuals, an early succession species in Great Basin sub-alpine forests.
Journal Article
SOIL IMPACTS OF BRISTLECONE PINE (PINUS LONGAEVA) TREE ISLANDS ON ALPINE TUNDRA, CHARLESTON PEAK, NEVADA
This study examines the influence of P. longaeva krummholz tree islands on soil chemical and physical properties just above treeline on Charleston Peak. Because of the presence of a substantial litter layer and the greater potential for snow and particle capture associated with the krummholz growth form, we expected that soil moisture and soil nutrients such as nitrogen (N) and phosphorus (P) would be higher, that pH values would be lower, and that soil particle size would be smaller beneath tree islands on Charleston Peak than in open tundra. The study was conducted above treeline on Charleston Peak (elevation 3632 m asl), located in the Spring Mountains in southern Nevada (36 degree 25'N, 115 degree 63'W), approximately 56 km northwest of Las Vegas.
Journal Article
Mechanisms of species range shift: germination and early survival of Great Basin bristlecone pine and limber pine
Aims
To examine the potential mechanistic predictors of germination and first-year survival in two species of Great Basin sub-alpine trees along an elevation gradient on three soil types.
Methods
Using a network of experimental gardens, we sowed limber pine and Great Basin bristlecone pine along elevational gradients at three sites on three different soil types. We collected germination and first-year survival data of each species while measuring temperature, soil water content, and other environmental variables to examine the potential predictors of first-year survival in these two species.
Results
Thanks to consecutive anomalously wet and dry years, we found germination and first-year survival to be largely limited by soil type, soil water content, and precipitation timing. Limber pine germination and survival showed weak negative responses while bristlecone pine germination and survival showed stronger negative responses to temperature.
Conclusions
Young trees are more sensitive to water limitation than to temperature and soil type has a strong moderating effect on water availability. Precipitation timing affected this availability with winter snowpack being less important in establishment than summer monsoonal rain. These results point to the importance of substrate and understanding limitations on all life stages when attempting to predict species range shifts.
Journal Article
A climate-driven tree line position model in the White Mountains of California over the past six millennia
Aim: Position of the alpine tree line ecotone around the globe corresponds to a growing season isotherm of approximately 6°C. Accordingly, tree lines are important indicators of Holocene global and regional environmental change. A central line of inquiry in tree line ecology is to better understand the mechanisms that dictate tree line position on the landscape, as well as the environmental conditions that cause upslope and downslope shifts in its position at centennial to millennial time-scales. Here, we present a climate-driven model to predict tree line position over the past 6,000 years. Location: Sheep Mountain, located in the White Mountain Range of California, USA. Time period: 4750 BCE to present. Major taxa studied: Great Basin bristlecone pine (Pinus longaeva BK Bailey). Methods: We use a climate-driven tree line position model that utilizes a topoclimate raster surface of growing season average temperature to predict the spatial position and area of the alpine tree line ecotone across the mountain range. We then produce a time series of tree line position predictions at 500-year intervals from 4750 BCE to present, and compare the predictions to the growth dates and spatial locations of 61 remnant bristlecone pine samples from above modern tree line. Results: The model indicates that tree line position in the White Mountains, CA migrated downslope throughout the Holocene until approximately 750 CE, rebounded slightly upslope by 1250 CE, and has since likely remained stationary. Applying the model under present-day climatic conditions suggests the current tree line at Sheep Mountain may be out of climatic equilibrium by up to 250 vertical metres in some places. Conclusion: The results support independent conclusions from global tree line analyses, underscore the temperature sensitivity of the tree line ecotone, and further develop our understanding of climate-driven tree line dynamics.
Journal Article