نتایج جستجو برای: pine tree resin

تعداد نتایج: 215918  

2016
Mary Anne S. Sayer Michael C. Tyree Michael A. Blazier Shi-Jean S. Sung Lori G. Eckhardt

In addition to selecting loblolly pine (Pinus taeda L.) genotypes for superior growth, the concept of customized genetic selection may apply where tree vigor is threatened by insects and disease. A study conducted with seedlings from 15 loblolly pine genotypes found significant correlation between phenolic production and foliage mass when dry mass allocation to the stem was relatively low. Vali...

Journal: :Evolution; international journal of organic evolution 1972
F Thomas Ledig John H Fryer

Steady state gene frequencies around a suming single gene inheritance and no dompocket of differential fitness have been forinance, Teich (1970) demonstrated that mulated by Hanson (1966) in a generalizapopulations of both jack pine and lodgepole tion of the work of Haldane (1948). A pine (Pinus contorta Dougl.) fit Hardypocket of differential fitness would result Weinberg expectations. The ele...

2013
Alma Piermattei Matteo Garbarino Francesco Renzaglia Carlo Urbinati

Scattered expansion of European black pine (Pinus nigra Arnold) has been observed above the current timberline in the central Apennines. We aimed to detect possible common pattern of structure and growth dynamics of pine regeneration in treeline sites. Over 700 black pine samples growing above the timberline were sampled at four sites in the limestone Apennines of Marche and Abruzzo regions. Fo...

2018
Christine C Chiu Christopher I Keeling Joerg Bohlmann

A recent outbreak of mountain pine beetle (MPB) has spread over more than 25 million hectares of pine forests in western North America, affecting pine species of sensitive boreal and mountain ecosystems. During initial host colonization, female MPB produce and release the aggregation pheromone trans-verbenol to coordinate a mass attack of individual trees. trans-Verbenol is formed by hydroxylat...

Journal: :PeerJ 2016
Zongzheng Chai Dexiang Wang

The mid-altitude zone of the Qinling Mountains in China was once dominated by birch and pine-oak belts but are now mainly covered by secondary growth following large-scale deforestation. Assessing the recovery and sustainability of these forests is essential for their management and restoration. We investigated and compared the tree species composition and community assemblages of secondary for...

2006
S. E. McKeand J. E. Grissom R. Rubilar

Loblolly pine is by far the most important forest tree species in the South, with over 1 billion seedlings planted annually by forest industry and non-industrial private forest landowners (McKeand et al. 2003). Genetic gains from tree improvement programs have been large, since geographic and within-provenance variation for growth and adaptive traits in loblolly pine is very large. General tren...

1999
FRANCO BIONDI JULIANNA E. FESSENDEN

We conducted dendroclimatic and stable isotope analyses of lodgepole pines (Pinus contorta) located in high-mortality sites at Mammoth Mountain (California, USA) to test for tree responses to magmatic degassing. Existing climatic and tree-ring data from nearby Yellowstone National Park were used for comparison. Sampled trees were scarcely sensitive to climate, and their growth showed an overall...

2004
Rafael Rubilar Steve McKeand H. Lee Allen

Intra-specific competition of loblolly pine (Pinus taeda) is a key factor for individual tree development. Liu and Burkhart (1994) indicated that at the seedling stage environmental gradients dominate on tree growth, where intraspecific competition dominate later stages of the stand. However, little information has been provided on how genetic material and intensive silviculture interactions af...

1996
James A. Powell Jason D. Rosey

A coupled partial diierential equation model for interaction between mountain pine beetles (MPB) and lodgepole pine is reviewed. An asymptoticòne-tree' solution is examined and time scale of the chemical response discussed. The equations are decoupled making an adiabatic assumption for MPB chemotaxis, and a `local' projection is made using the leading eigenfunction for the MPB density equation....

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
Brian J Harvey Daniel C Donato Monica G Turner

Widespread tree mortality caused by outbreaks of native bark beetles (Circulionidae: Scolytinae) in recent decades has raised concern among scientists and forest managers about whether beetle outbreaks fuel more ecologically severe forest fires and impair postfire resilience. To investigate this question, we collected extensive field data following multiple fires that burned subalpine forests i...

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