Canopy gaps affect long-term patterns of tree growth and mortality in mature and old-growth forests in the Pacific Northwest

2012 ◽  
Vol 281 ◽  
pp. 111-120 ◽  
Author(s):  
Andrew N. Gray ◽  
Thomas A. Spies ◽  
Robert J. Pabst
Keyword(s):  
Pacific Northwest ◽  
Tree Growth ◽  
Canopy Gaps ◽  
Old Growth ◽  
The Pacific ◽  
Old Growth Forests

scholarly journals Monitoring late-successional forest biodiversity in the Pacific Northwest, U.S.A.

2006 ◽  
Vol 82 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Thomas A Spies ◽  
Jon R Martin
Keyword(s):  
Endangered Species ◽  
Pacific Northwest ◽  
Satellite Imagery ◽  
Ecosystem Management ◽  
Biological Diversity ◽  
Old Growth ◽  
Monitoring Plan ◽  
Effectiveness Monitoring ◽  
The Pacific ◽  
Old Growth Forests

The era of ecosystem management for federal forest lands in the Pacific Northwest began in 1994 with the adoption of the Northwest Forest Plan. This plan was designed to maintain and restore species and ecosystems associated with late successional and old-growth forests on over 10 million ha of federal lands in Washington, Oregon and California. The plan called for implementation monitoring, effectiveness monitoring, and validation monitoring for a variety of ecological and socio-economic components. Monitoring has become a central part of management of the federal forests in the region and managers and scientists have gained considerable experience in implementing this large and complex program. The components of the monitoring plan include late-successional/old growth vegetation, northern spotted owls, marbled murrelets, aquatic habitat and social conditions. The monitoring plan is strongly based on vegetation layer created with TM satellite imagery and on a regional grid of forest inventory plots. The lessons learned from the implementation of this monitoring plan include: 1) agencies need to devote considerable resources to insure that effective monitoring will occur at broad scales; 2) aggregation of local monitoring efforts is not a substitute for a designed regional monitoring plan; 3) vegetation structure and composition, measured with satellite imagery and inventory plots, is a cost-effective, broad-scale indicator of biological diversity; 4) some species, such as threatened and endangered species, are not necessarily covered with habitat approaches and may require population monitoring; 5) our scientific understanding of monitoring components will vary widely as will the approaches to data collection and analysis; 6) monitoring requires research support to develop and test metrics and biodiversity models; 7) links of monitoring to decision-making (adaptive management) are still being forged. Key words: aquatic ecosystems, endangered species, old-growth forests, Pacific Northwest, USA, regional ecosystem management

Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia

2004 ◽  
Vol 34 (12) ◽  
pp. 2455-2466 ◽  
Author(s):  
Tanya R Wahbe ◽  
Fred L Bunnell ◽  
R Bruce Bury
Keyword(s):  
Pacific Northwest ◽  
Conservation Status ◽  
Population Monitoring ◽  
Timber Harvest ◽  
Long Distance ◽  
Old Growth ◽  
Ascaphus Truei ◽  
Drift Fence ◽  
The Pacific

Tailed frog (Ascaphus truei Stejneger) populations are at risk in much of the Pacific Northwest, and recolonization of sites may be slow postlogging. To examine the terrestrial movements of Ascaphus in clearcuts and old growth, we employed pitfall traps and drift-fence arrays installed along streams and 100 m into upland habitat. In the fall, we captured frogs farther from streams in old growth than in clearcuts, and more frogs were captured ≤25 m from streams in clearcuts. Stronger stream affinity in clearcuts was most evident with juvenile frogs, which exhibited more upstream movements than adults. Compared with inland sites where frogs remained close to streams (e.g., 12 m), frogs at our coastal sites were captured at greater distances from streams (≥100 m), having lower stream affinity than frogs at inland sites. Long-distance overland movements appear more likely where forested stands are present. Aggregations of Ascaphus at individual streams may not represent distinct populations and should not be managed as distinct units. Preserving groups of interconnected streams within watersheds instead of individual streams will improve the conservation status of Ascaphus. Population monitoring can ensure conservation measures promote long-term persistence.

Status of Mature and Old-Growth Forests in the Pacific Northwest

2006 ◽  
Vol 20 (2) ◽  
pp. 363-374 ◽  
Author(s):  
JAMES R. STRITTHOLT ◽  
DOMINICK A. DELLASALA ◽  
HONG JIANG
Keyword(s):  
Pacific Northwest ◽  
Old Growth ◽  
The Pacific ◽  
Old Growth Forests

Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt
Keyword(s):  
Pacific Northwest ◽  
Variable Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
The Pacific ◽  
History Of ◽  
Horizontal Heterogeneity ◽  
Restoration Strategies

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.

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