Achieving Conservation Biology Objectives with Fire in the Pacific Northwest

1996 ◽  
Vol 10 (2) ◽  
pp. 417-421 ◽  
Author(s):  
James K. Agee
Keyword(s):  
Pacific Northwest ◽  
Conservation Biology ◽  
Ponderosa Pine ◽  
Fire Regime ◽  
Fire Frequency ◽  
Dispersal Ability ◽  
Natural Ecosystems ◽  
High Dispersal ◽  
The Pacific ◽  
Ecosystem Level

Fire has been a part of natural ecosystems for many millennia. The species of those ecosystems have evolved through a series of “coarse filters,” one of which is resistance or resilience to disturbance by fire. Plant adaptations to fire include the ability to sprout, seed bank adaptations in the soil or canopy, high dispersal ability for seeds, and thick bark. These adaptations are often to a particular fire regime, or combination of fire frequency, intensity, extent, and season. Fire can be used by managers to achieve species to ecosystem-level conservation biology objectives. Examples using prescribed fire include the grasslands of the Puget Trough of Washington State, maintenance of oak woodlands, and perpetuation of ponderosa pine/mixed-conifer forests.

scholarly journals Identifying cryptic diversity with predictive phylogeography

2016 ◽  
Vol 283 (1841) ◽  
pp. 20161529 ◽  
Author(s):  
Anahí Espíndola ◽  
Megan Ruffley ◽  
Megan L. Smith ◽  
Bryan C. Carstens ◽  
David C. Tank ◽  
...  
Keyword(s):  
North America ◽  
Pacific Northwest ◽  
Biological Diversity ◽  
Single Species ◽  
Cryptic Diversity ◽  
Major Goal ◽  
Organismal Biology ◽  
Unknown Species ◽  
The Pacific ◽  
Ecosystem Level

Identifying units of biological diversity is a major goal of organismal biology. An increasing literature has focused on the importance of cryptic diversity, defined as the presence of deeply diverged lineages within a single species. While most discoveries of cryptic lineages proceed on a taxon-by-taxon basis, rapid assessments of biodiversity are needed to inform conservation policy and decision-making. Here, we introduce a predictive framework for phylogeography that allows rapidly identifying cryptic diversity. Our approach proceeds by collecting environmental, taxonomic and genetic data from codistributed taxa with known phylogeographic histories. We define these taxa as a reference set, and categorize them as either harbouring or lacking cryptic diversity. We then build a random forest classifier that allows us to predict which other taxa endemic to the same biome are likely to contain cryptic diversity. We apply this framework to data from two sets of disjunct ecosystems known to harbour taxa with cryptic diversity: the mesic temperate forests of the Pacific Northwest of North America and the arid lands of Southwestern North America. The predictive approach presented here is accurate, with prediction accuracies placed between 65% and 98.79% depending of the ecosystem. This seems to indicate that our method can be successfully used to address ecosystem-level questions about cryptic diversity. Further, our application for the prediction of the cryptic/non-cryptic nature of unknown species is easily applicable and provides results that agree with recent discoveries from those systems. Our results demonstrate that the transition of phylogeography from a descriptive to a predictive discipline is possible and effective.

scholarly journals Toward a better understanding of climate and human impacts on late Holocene fire regimes in the Pacific Northwest, USA

2018 ◽  
Vol 42 (4) ◽  
pp. 478-512 ◽  
Author(s):  
Megan K Walsh ◽  
Haley J Duke ◽  
Kevin C Haydon
Keyword(s):  
Pacific Northwest ◽  
Ponderosa Pine ◽  
Late Holocene ◽  
Human Impacts ◽  
Fire Severity ◽  
Fire Regimes ◽  
The Past ◽  
The Pacific ◽  
Clackamas County ◽  
Study Sites

In order to fully appreciate the role that fire, both natural and anthropogenic, had in shaping pre-Euro-American settlement landscapes in the Pacific Northwest (PNW), it is necessary to develop a more robust method of evaluating paleofire reconstructions. Here we demonstrate an approach that includes the identification of charcoal morphotypes (i.e. visually distinct charcoal particles), and incorporates both paleoecological and archaeological data sets, to more specifically determine both the nature of past fire regimes (i.e. fuel type and fire severity) and the likely ignition source of those fires. We demonstrate the usefulness of this approach by reconstructing the late Holocene fire and vegetation histories of Lake Oswego (Clackamas County), Oregon, and Fish Lake (Okanogan County), Washington, using macroscopic charcoal and pollen analysis of sediment cores. The histories were compared with climatic records from the PNW as well as archaeological, ethnographic, and historical records from the Lower Columbia River Valley and Southern Columbia Plateau cultural regions. Our results indicate that while centennial-to-millennial-scale climate change had limited influence on the fire regimes at the study sites during the past ∼3800 years, the use of fire by Native Americans for a variety of reasons, particularly after ca. 1200 calendar years before present (AD 750), had a far greater impact. Charcoal morphotype ratios also indicate that fires in the two watersheds were fundamentally different in their severity and impact, and led to major shifts in the forests and woodlands surrounding Lake Oswego, but helped maintain the ponderosa pine-dominated forest at Fish Lake. The elimination of fire from the two study sites during the past 100–300 years is likely the combined result of Euro-American contact and the arrival of disease in the PNW, as well as 20th-century fire suppression and grazing effects on fuel continuity, which has implications for future forest management and restoration efforts in the PNW.

Comparing methods of reconstructing fire history using fire scars in a southwestern United States ponderosa pine forest

2006 ◽  
Vol 36 (4) ◽  
pp. 855-867 ◽  
Author(s):  
Megan L Van Horne ◽  
Peter Z Fulé
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Fire History ◽  
Sampling Methods ◽  
Fire Regime ◽  
Fire Frequency ◽  
Fire Scars ◽  
Fire Scar ◽  
Targeted Sampling ◽  
Fire Intervals

Fire scars have been used to understand the historical role of fire in ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) ecosystems, but sampling methods and interpretation of results have been criticized for being statistically invalid and biased and for leading to exaggerated estimates of fire frequency. We compared "targeted" sampling, random sampling, and grid-based sampling to a census of all 1479 fire-scarred trees in a 1 km2 study site in northern Arizona. Of these trees, 1246 were sufficiently intact to collect cross-sections; of these, 648 had fire scars that could be cross-dated to the year of occurrence in the 200-year analysis period. Given a sufficient sample size (approximately n ≥ 50), we concluded that all tested sampling methods resulted in accurate estimates of the census fire frequency, with mean fire intervals within 1 year of the census mean. We also assessed three analytical techniques: (1) fire intervals from individual trees, (2) the interval between the tree origin and the first scar, and (3) proportional filtering. "Bracketing" fire regime statistics to account for purported uncertainty associated with targeted sampling was not useful. Quantifying differences in sampling approaches cannot resolve all the limitations of fire-scar methods, but does strengthen interpretation of these data.

scholarly journals Forest Fragmentation: Wildlife and Management Implications

2000 ◽  
Vol 6 (3) ◽  
pp. 273
Author(s):  
Jarrad Cousin
Keyword(s):  
Pacific Northwest ◽  
Natural Ecosystems ◽  
Management Implications ◽  
Silvicultural Practices ◽  
South West ◽  
The Pacific ◽  
Eastern Australia ◽  
The World ◽  
Forested Ecosystems ◽  
Broad Scale

Fragmentation of natural ecosystems occurs throughout the world due to processes such as agriculture, forestry, mining and urbanization. Much of the wheatbelt regions of south-west and eastern Australia face major problems relating to the decline and extinction of resident flora and fauna. Much of the problem relates to the lack of knowledge of the processes and consequences of fragmentation. By the time problems have been addressed, damage to the ecosystems are often irreparable. In North America, much of the forested regions of the Pacific Northwest have also experienced broad-scale fragmentation of the natural forested ecosystems through extensive silvicultural practices.

Sign in / Sign up

Export Citation Format

Share Document