scholarly journals Distribución altitudinal del género Pinus en el oeste de Estados Unidos de América y México

2017 ◽  
pp. 55
Author(s):  
Richard I. Yeaton
Keyword(s):  
United States ◽  
Resource Partitioning ◽  
Morphological Characteristics ◽  
The Other ◽  
Western United States ◽  
Mountain Ranges ◽  
Species Pairs ◽  
Associated Species ◽  
Species Being ◽  
Altitudinal Distributions

The altitudinal distributions of members of the genus Pinus were studied on mountain ranges in the western United States and Mexico. The community of pines on each mountainside consists of members of three major groupings - long-needled Diploxylon species, short-needled Diploxylon species and Haploxylon species. Long-needled Diploxylon species form a core sequence of altitudinally replacing species over whose distribution are superimposed sequences of members of one of the other two groups. In the northern mountains ranges Haploxylon species formed this second sequence while in the southern ranges short-neddled Diploxylon species assumed this role. Some morphological characteristics of these species were examined and random associations of species pairs generated using these characteristics. The results suggest that resource partitioning between altitudinally associated species does not occur but rather that a successional situatton exists with long-needled Diploxylon species being replaced by either Haploxylon in the norrhern ranges or short-needled Diploxylon species in the southern ranges.

Pleistocene relief production in Laramide mountain ranges, western United States: Comment and Reply

Geology ◽  
1998 ◽  
Vol 26 (12) ◽  
pp. 1150 ◽  
Author(s):  
Jeffrey P. Schaffer ◽  
Eric E. Small ◽  
Robert S. Anderson
Keyword(s):  
United States ◽  
Western United States ◽  
Mountain Ranges

scholarly journals Stand-Level Height-Diameter Equations for Young Ponderosa Pine Plantations in Neuquén, Patagonia, Argentina: Evaluating Applications of Equations Developed in the Western United States

2004 ◽  
Vol 19 (3) ◽  
pp. 202-210
Author(s):  
Héctor E. Gonda ◽  
Douglas A. Maguire ◽  
Gustavo O. Cortés ◽  
Steven D. Tesch
Keyword(s):  
United States ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Nonlinear Models ◽  
Geographic Range ◽  
The Other ◽  
Linear Functions ◽  
Western United States ◽  
Northern Patagonia ◽  
Level Height

Abstract Two linear and two nonlinear height-diameter models commonly used in the western United States were tested for the young ponderosa pine (Pinus ponderosa) plantations of northern Patagonia, where it is the most widely planted species. The equations were fitted to each of 127 plots, located throughout the geographic range of the plantations in Neuquén province. The four equations were compared using Furnival's (1961) index of fit. Even though there were no important differences among models tested, the nonlinear model previously applied by Wykoff et al. (1982), H = 1.3 + exp(β0 + (β1/(D + 2.54))) + β was preferable because it converged more efficiently than the other nonlinear equation and was more flexible than the linear functions. Differences in the behavior of plot-level and regionwide equations demonstrated the biases possible if regionwide equations are applied to estimate missing heights within a plot. The coefficients for the two nonlinear models fitted to trees growing in several regions in the western United States generally overestimated the height of Neuquén trees. West. J. Appl. For. 19(3):202–210.

scholarly journals Ambient Factors Controlling the Wintertime Precipitation Distribution across Mountain Ranges in the Interior Western United States. Part II: Changes in Orographic Precipitation Distribution in a Pseudo–Global Warming Simulation

2019 ◽  
Vol 58 (4) ◽  
pp. 695-715 ◽  
Author(s):  
Xiaoqin Jing ◽  
Bart Geerts ◽  
Yonggang Wang ◽  
Changhai Liu
Keyword(s):  
United States ◽  
Global Warming ◽  
Western United States ◽  
Cmip5 Models ◽  
Cloud Base ◽  
Orographic Precipitation ◽  
Precipitation Distribution ◽  
Mountain Ranges ◽  
Ensemble Mean ◽  
Precipitation Increase

AbstractTwo high-resolution (4 km) regional climate simulations over a 10-yr period are conducted to study the changes in wintertime precipitation distribution across mountain ranges in the interior western United States (IWUS) in a warming climate. One simulation represents the current climate, and another represents an ~2050 climate using a pseudo–global warming approach. The climate perturbations are derived from the ensemble mean of 15 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). These simulations provide an estimate of average changes in wintertime orographic precipitation enhancement and finescale distribution across mountain ranges. The variability in these changes among CMIP5 models is quantified using statistical downscaling relations between orographic precipitation distribution and upstream conditions, developed in Part I. The CMIP5 guidance indicates a robust warming signal (~2 K) over the IWUS by ~2050 but minor changes in relative humidity and cloud-base height. The IWUS simulations reveal a widespread increase in precipitation on account of higher precipitation rates during winter storms in this warmer climate. This precipitation increase is most significant over the mountains rather than on the surrounding plains. The increase in precipitation rate is largely due to an increase in low-level cross-mountain moisture transport. The application of the statistical relations indicates that individual CMIP5 models disagree about the magnitude and distribution of orographic precipitation change in the IWUS, although most agree with the ensemble-mean-predicted orographic precipitation increase.

scholarly journals New subspecies of fir dwarf mistletoe (Arceuthobium abietinum: Viscaceae) from the western United States and northern Mexico

2020 ◽  
Vol 14 (1) ◽  
pp. 27-45
Author(s):  
Shawn C. Kenaley
Keyword(s):  
United States ◽  
Host Range ◽  
Plant Height ◽  
Rocky Mountain ◽  
The Other ◽  
Western United States ◽  
Dwarf Mistletoe ◽  
New Subspecies ◽  
Northern Mexico ◽  
White Fir

Two new subspecies of fir dwarf mistletoe (Arceuthobium abietinum, Viscaceae) are described herein: Arceuthobium abietinum subsp. mathiasenii (Mathiasen’s dwarf mistletoe) and Arceuthobium abietinum subsp. grandae (grand fir dwarf mistletoe). The former dwarf mistletoe—Mathiasen’s dwarf mistletoe—parasitizes Rocky Mountain white fir in Nevada, Utah, and Arizona and Durango fir in northern Mexico; whereas, grand fir dwarf mistletoe parasitizes grand fir as well grand fir × white fir hybrids in California, Oregon and Washington. The recognition of these subspecies and, hence, their classification is based on morphological discontinuities and host range differences when compared to white fir dwarf mistletoe (Arceuthobium abietinum subsp. abietinum), red fir dwarf mistletoe (A. abietinum subsp. magnificae), and Wiens’ dwarf mistletoe (A. abietinum subsp. wiensii). The combined analyses of plant height, third internode length and width, fruit dimensions, staminate spike and petal dimensions, and anther distance to tip, contributed most to the discrimination of subsp. grandae and mathiasenii from subsp. abietinum and magnificae. The flowers of Mathiasen's dwarf mistletoe were larger than all of the other taxa classified under A. abietinum. The shoot color of Mathiasen’s dwarf mistletoe was frequently blue-green, brown, yellow-brown, or red-brown, and plants were often highly glaucous, while the shoot color of the other subspecies were typically yellow-green or yellow, except for Wiens' dwarf mistletoe whose shoots are often green-brown or red-brown. Differences in host specificity and geographic distribution also distinguish the new subspecies from the other taxa of A. abietinum.

Forest Canopy Density Effects on Snowpack across the Climate Gradients of the Western United States Mountain Ranges

2022 ◽  
Author(s):  
Ning Sun ◽  
Hongxiang Yan ◽  
Mark S. Wigmosta ◽  
Jessica Lundquist ◽  
Susan Dickerson‐Lange ◽  
...  
Keyword(s):  
United States ◽  
Forest Canopy ◽  
Western United States ◽  
Canopy Density ◽  
Climate Gradients ◽  
Mountain Ranges ◽  
Density Effects ◽  
Forest Canopy Density

scholarly journals Biomass burning contribution to black carbon in the Western United States Mountain Ranges

2011 ◽  
Vol 11 (21) ◽  
pp. 11253-11266 ◽  
Author(s):  
Y. H. Mao ◽  
Q. B. Li ◽  
L. Zhang ◽  
Y. Chen ◽  
J. T. Randerson ◽  
...  
Keyword(s):  
United States ◽  
Black Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Transport Model ◽  
Reanalysis Data ◽  
Western United States ◽  
Fire Season ◽  
Carbonaceous Aerosols ◽  
Mountain Ranges

Abstract. Forest fires are an important source to carbonaceous aerosols in the Western United States (WUS). We quantify the relative contribution of biomass burning to black carbon (BC) in the WUS mountain ranges by analyzing surface BC observations for 2006 from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using the GEOS-Chem global chemical transport model. Observed surface BC concentrations show broad maxima during late June to early November. Enhanced potassium concentrations and potassium/sulfur ratios observed during the high-BC events indicate a dominant biomass burning influence during the peak fire season. Model surface BC reproduces the observed day-to day and synoptic variabilities in regions downwind of but near urban centers. Major discrepancies are found at elevated mountainous sites during the July-October fire season when simulated BC concentrations are biased low by a factor of two. We attribute these low biases largely to the underestimated (by more than a factor of two) and temporally misplaced biomass burning emissions of BC in the model. Additionally, we find that the biomass burning contribution to surface BC concentrations in the USA likely was underestimated in a previous study using GEOS-Chem (Park et al., 2003), because of the unusually low planetary boundary layer (PBL) heights in the GEOS-3 meteorological reanalysis data used to drive the model. PBL heights from GEOS-4 and GEOS-5 reanalysis data are comparable to those from the North American Regional Reanalysis (NARR). Model simulations show slightly improved agreements with the observations when driven by GEOS-5 reanalysis data, but model results are still biased low. The use of biomass burning emissions with diurnal cycle, synoptic variability, and plume injection has relatively small impact on the simulated surface BC concentrations in the WUS.

scholarly journals First Report of Rust Caused by Puccinia allii on Wild Garlic in California

Plant Disease ◽  
2001 ◽  
Vol 85 (12) ◽  
pp. 1290-1290 ◽  
Author(s):  
S. T. Koike ◽  
R. F. Smith
Keyword(s):  
United States ◽  
Allium Sativum ◽  
Rust Fungus ◽  
Morphological Characteristics ◽  
Western United States ◽  
Rust Disease ◽  
Perennial Weed ◽  
First Report ◽  
Wild Garlic ◽  
Puccinia Allii

Wild garlic (Allium vineale) is a bulbous perennial weed that was introduced from Europe and is now established throughout the eastern and much of the western United States. In 2001, wild garlic plants growing in Monterey County, CA were infected with a rust fungus. Uredinia and telia were present on leaves, resulting in small (2 to 5 mm long) lesions; however, leaf dieback and other symptoms were not observed. The orange urediniospores were spherical to ellipsoidal, echinulate, and mea-sured 26 to 30 × 25 to 28 μm. Telia were black in mass and divided into locules by fused paraphyses. Teliospores were located within the locules and were brown, smooth-walled, two-celled, and measured 40 to 50 × 17 to 20 μm. Teliospore pedicels were hyaline, usually fractured, and measured 3 to 15 μm. One-celled mesospores were not observed. Based on these morphological characteristics, the pathogen was identified as Puccinia allii (1,2). To our knowledge, this is the first report of rust caused by P. allii on wild garlic in California. Because of this finding, an experiment was designed to determine whether wild garlic could be a source of rust inoculum for commercial allium crops. Wild garlic bulbs were planted in 4-in. pots (10 cm square) and grown in a greenhouse. At the 4- to 5-leaf stage the plants were transplanted in a garlic (Allium sativum) cultivar trial that had been inoculated with an isolate of P. allii from garlic. When plants were evaluated 2 months later, uredinia and telia were observed on the wild garlic plants, and the fungus was confirmed to be P. allii. Wild garlic, therefore, could be a source of overwintered inocula for the rust disease that occurs on commercial garlic and onion (A. cepa) in California (2). References: (1) D. M. Jennings et al. Mycol. Res. 94:83, 1990. (2) S. T. Koike et al. Plant Dis. 85:585, 2001.

Ecology of Euphausiids in the Gulf of St. Lawrence

1976 ◽  
Vol 33 (9) ◽  
pp. 1894-1905 ◽  
Author(s):  
F. Berkes
Keyword(s):  
Resource Partitioning ◽  
Phytoplankton Bloom ◽  
Distribution Patterns ◽  
Reproductive Season ◽  
The Other ◽  
Species Pairs ◽  
Vertical Distributions ◽  
Oceanic Species ◽  
Food And Feeding ◽  
Meganyctiphanes Norvegica

Geographical and vertical distributions, reproduction, growth and maturity, food and feeding of Meganyctiphanes norvegica, Thysanoessa raschii, T. inermis, and T. longicaudata in the Gulf of St. Lawrence were studied, based on plankton samples from 10 cruises, largely from 2 consecutive yr. Adults of the first three species occurred most abundantly in the western Gulf and their larvae in the Magdalen Shallows. By contrast, T. longicaudata, an oceanic species, occurred mainly in the eastern Gulf year-round. All four species reached reproductive maturity at 1 yr of age; all but T. longicaudata populations contained at least two breeding year-classes. The three Thysanoessa species started spawning in April at the time of the phytoplankton bloom; M. norvegica was a summer breeder. All four species were omnivorous, but M. norvegica and T. longicaudata stomachs contained relatively more animal matter than those of the other two. These findings were supported by studies on the morphology of feeding appendages.Thysanoessa longicaudata was differentiated from the other species mainly on the basis of distribution patterns, and M. norvegica from the remaining two mainly on the basis of differences in feeding and reproductive season. In contrast to relatively clear resource partitioning in five of the six species pairs, only relatively small differences in the stomach content composition in winter samples, the spacing of setules, and the length of the breeding season differentiated T. inermis from T. raschii.

scholarly journals Biomass burning contribution to black carbon in the western United States mountain ranges

2011 ◽  
Vol 11 (5) ◽  
pp. 13425-13467 ◽  
Author(s):  
Y. Mao ◽  
Q. Li ◽  
L. Zhang ◽  
Y. Chen ◽  
J. T. Randerson ◽  
...  
Keyword(s):  
United States ◽  
Black Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Transport Model ◽  
Reanalysis Data ◽  
Western United States ◽  
Fire Season ◽  
Carbonaceous Aerosols ◽  
Mountain Ranges

Abstract. Forest fires are an important source to carbonaceous aerosols in the western United States (WUS). We quantify the relative contribution of biomass burning to black carbon (BC) in the WUS mountain ranges by analyzing surface BC observations for 2006 from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using the GEOS-Chem global chemical transport model. Observed surface BC concentrations show broad maxima during late June to early November. Enhanced potassium concentrations and potassium/sulfur ratios observed during the high-BC events indicate a dominant biomass burning influence during the peak fire season. Model surface BC reproduces the observed day-to-day and synoptic variabilities in regions downwind of and near urban centers. Major discrepancies are found at elevated mountainous sites during the July–October when simulated BC concentrations are biased low by a factor of two. We attribute these biases largely to the underestimated and temporally misplaced biomass burning emissions of BC in the model. Additionally, we find that the biomass burning contribution to surface BC concentrations in the US likely was underestimated in a previous study using GEOS-Chem (Park et al., 2003), because of the unusually low planetary boundary layer (PBL) heights and weak precipitation in the GEOS-3 meteorological reanalysis data used to drive the model. PBL heights from GEOS-4 and GEOS-5 reanalysis data are comparable to those from the North American Regional Reanalysis (NARR). Model simulations show improved agreements with the observations when driven by GEOS-5 reanalysis data, but model results are still biased low. The use of biomass burning emissions with diurnal cycle, synoptic variability, and plume injection has relatively small impact on the simulated surface BC concentrations in the WUS.

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