scholarly journals Late Holocene expansion of ponderosa pine (Pinus ponderosa ) in the Central Rocky Mountains, USA

2015 ◽  
Vol 43 (4) ◽  
pp. 778-790 ◽  
Author(s):  
Jodi R. Norris ◽  
Julio L. Betancourt ◽  
Stephen T. Jackson
2013 ◽  
Vol 80 (3) ◽  
pp. 406-416 ◽  
Author(s):  
Vachel A. Carter ◽  
Andrea Brunelle ◽  
Thomas A. Minckley ◽  
Philip E. Dennison ◽  
Mitchell J. Power

Fire is one of the most important natural disturbances in the coniferous forests of the US Rocky Mountains. The Rocky Mountains are separated by a climatic boundary between 40° and 45° N, which we refer to as the central Rocky Mountains (CRM). To determine whether the fire regime from the CRM was more similar to the northern Rocky Mountains (NRM) or southern Rocky Mountains (SRM) during the Holocene, a 12,539-yr-old sediment core from Long Lake, Wyoming, located in the CRM was analyzed for charcoal and pollen. These data were then compared to charcoal records from the CRM, NRM and SRM. During the Younger Dryas chronozone, the fire regime was characterized as frequent at Long Lake. The early and middle Holocene fire regime was characterized as infrequent. A brief interval from 4000 to 3000 cal yr BP, termed the Populus period, had a frequent fire regime and remained frequent through the late Holocene at Long Lake. In comparison to sites from the NRM and SRM, the fire regime at Long Lake was most similar to the SRM during the past 12,539 cal yr BP. These results suggest the disturbance regime in the CRM has a greater affinity with those of the SRM.


1997 ◽  
Vol 75 (12) ◽  
pp. 2107-2111 ◽  
Author(s):  
Marc A. Snyder ◽  
Yan B. Linhart

The North American porcupine (Erethizon dorsatum) is a feeding generalist, but can feed primarily on phloem of the ponderosa pine (Pinus ponderosa) during winter months in areas of the Rocky Mountains where ponderosa pine occurs in nearly pure stands. This pine is highly variable both in resin monoterpene composition and at the allozyme level. Porcupines can girdle branches or whole trees when eating phloem, and in the process often damage or kill the trees. Trees that had been fed upon (target trees) differed biochemically and genetically from adjacent trees that had not been fed upon (nontarget trees). Target trees had lower levels of the monoterpene limonene in the xylem oleoresin than matched nontarget trees, and there was a significant negative association between levels of limonene and the amount of phloem removed from individual trees. Target trees differed only slightly from nontarget trees in allele frequencies at two of nine polymorphic loci tested. When the feeding patterns of porcupines were compared with those of a previously studied mammal that feeds primarily on the phloem of ponderosa pine, Abert's squirrel (Sciurus aberti), the level of feeding selectivity was found to be far less pronounced in the porcupine.


IAVS Bulletin ◽  
2018 ◽  
Vol 2018 (3) ◽  
pp. 16-50
Author(s):  
Orsolya Valkó ◽  
◽  
Balázs Deák

1999 ◽  
Vol 14 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Michael J. Pipas ◽  
Gary W. Witmer

Abstract A 2 yr study on the Rogue River and Mt. Hood National Forests in Oregon evaluated physical barriers for protection of Pinus ponderosa seedlings against damage by Thomomys talpoides. Seedlings protected with one of three weights of: (1) plastic mesh tubing (Vexar®) or (2) sandpapertubing (Durite®) were evaluated against control seedlings. On the Rogue River sites, Vexar® seedlings had the highest survival (62.6%), followed by the controls (59.1%), then Durite® seedlings (17.9%). Gophers were the primary cause of death for the Vexar® seedlings, versus desiccation for the Durite® seedlings. On the Mt. Hood sites, heavyweight Vexar® seedlings had the highest survival (35.4%), medium-weight Durite® seedlings the lowest (2.7%). Seedling mortality caused by gophers was highest for controls (70.2%), followed by light-weight (62.2%) and heavy-weight (53.9%) Vexar® treatments. Overall survival was low (Rogue River = 42%, Mt. Hood = 19.8%). Growth was greatest for the control seedlings but only significantly greater than growth of Durite® seedlings on the Rogue River sites. Growth of seedlings was not compromised by the Vexar® tubing. Although neither type of tubing was highly protective, Vexar® tubes performed better than Durite® tubes. West. J. Appl. For. 14(3):164-168.


2003 ◽  
Vol 18 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Steven J. Stein ◽  
Diana N. Kimberling

Abstract Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.


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