Old-growth, disturbance, and ecosystem management: Commentary

1996 ◽  
Vol 74 (4) ◽  
pp. 509-510 ◽  
Author(s):  
David L. Martell
1996 ◽  
Vol 74 (4) ◽  
pp. 511-511
Author(s):  
E. A. Johnson ◽  
K. Miyanishi ◽  
J. M. H. Weir

1995 ◽  
Vol 73 (6) ◽  
pp. 918-926 ◽  
Author(s):  
E. A. Johnson ◽  
K. Miyanishi ◽  
J. M. H. Weir

The forested landscape consists of a mosaic of patches of different times since the last disturbance (i.e., different stand ages). Therefore, we can form a distribution of forest ages for the entire landscape (landscape age distribution). Studies of disturbance by fire in boreal and subalpine conifer forests have shown that the cumulative age distribution (landscape survivorship distribution) is best fit by a negative exponential model for which the parameter, the disturbance cycle, gives the time required to disturb an area equal in size to the study area. This distribution describes the rate at which parts of the landscape will survive disturbance, and consequently it tells us the percentage of the landscape that will survive to be old-growth forest. Empirical studies show that old forests make up a small proportion of the boreal and subalpine landscape. We introduce the concept of characteristic oldest age, which is a function of disturbance cycle and size of the study area. This landscape approach to old growth allows one to estimate the minimum area required to ensure the continued existence of some user-defined old-growth forest for any given disturbance cycle. Key words: old growth, disturbance cycle, ecosystem management, landscape age distribution, boreal forest, landscape ecology.


2006 ◽  
Vol 82 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Thomas A Spies ◽  
Jon R Martin

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


2003 ◽  
Vol 11 (S1) ◽  
pp. S159-S185 ◽  
Author(s):  
Steven G Newmaster ◽  
René J Belland ◽  
André Arsenault ◽  
Dale H Vitt

Mosses and hepatics (bryophytes) are the most diverse and abundant understorey vegetation within the Coastal Western Hemlock (CWH) and Interior Cedar–Hemlock (ICH) zones of British Columbia. This study intensively sampled bryophytes in 287 young- and old-growth stands in the CWH and ICH zones. Two major variables strongly influence the patterning of bryophyte diversity in these zones: stand age and habitat heterogeneity. Canonical correspondence analyses (CCA) identified these as the most important variables explaining stand–environment interactions. Alpha diversity is much greater in old-growth forests and beta diversity is high between young and old forests. Old-growth cedar–hemlock forests have between 60 (ICH) and 100% (CWH) more species than younger forests disturbed by wildfire in the ICH zones or logging in the CWH zones. Furthermore, a stand classification built on species composition partitioned species into stands of different ages and mesohabitat heterogeneity. Beta diversity was also partitioned between stands of different ages and habitat heterogeneity. This indicates that both young and old forests have a unique assemblage of species. Indicator analysis was used to choose a partial lists of species that are indicators of "old growthness". These old forests support a rich flora of hepatics and rare western North American endemics. High environmental continuity is associated with the most humid watersheds and cedar–hemlock forests within these watersheds have the highest bryophyte diversity. The establishment of rich communities of bryophytes in the moist cedar–hemlock forest has been occurring over the last 2000–7000 years, with the coastal rainforest much older than the inland rainforest. Large-scale disturbance, such as forestry, threatens the existence of these highly diverse communities. A better understanding of the patterning of bryophyte diversity will provide an opportunity to minimize the impact of forest operations on biodiversity. Bryophyte diversity in British Columbia cedar–hemlock forests will be sustained through ecosystem management of old-growth legacies (i.e., landscapes, stands, and their components) and preservation of areas of high diversity. Temporal and habitat variables are influential in the patterning of bryophyte diversity. Management plans that consider these variables will be better equipped to manage cedar–hemlock forests for maintaining biodiversity. Key words: biodiversity, bryophytes, cedar–hemlock, CWH, disturbance, ecosystem management, floristic habitat sampling, forest conservation, ICH, old growth, patterning of diversity, rare species, species richness.


Silva Fennica ◽  
2011 ◽  
Vol 45 (5) ◽  
Author(s):  
Annie Bélisle ◽  
Sylvie Gauthier ◽  
Dominic Cyr ◽  
Yves Bergeron ◽  
Hubert Morin

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 578
Author(s):  
Jean-Claude Ruel

Research Highlights: Windthrow can interfere significantly with ecosystem management practices. In some cases, their goal could still be reached but this may prove more complex in other cases, like the partial cutting of old-growth stands. In situations where windthrow is common without any human intervention, the use of partial cutting to maintain some stand structures may lead to a feedback loop leading to additional windthrow. Background and Objectives: Forest ecosystem management using natural disturbances as a template has become the management paradigm in many regions. Most of the time, the focus is on fire regime and effects. However, windthrow can be common in some places or can interfere with practices implemented in an ecosystem management strategy. This paper looks at interactions between ecosystem management and windthrow. Materials and Methods: The paper builds on three case studies looking at various elements that could be part of ecosystem management strategies. The first one looks at the impact of green tree retention, while the second one looks at the impact of reducing the size and dispersing clearcuts, and the last one examines the impact of a range of cutting practices in irregular old-growth stands. Results: Green tree retention leads to increased windthrow, especially when applied within mature even-aged stands. Reducing the size of clearcuts and dispersing them over the landscape also involves substantial windthrow along edges. Partial cutting in old-growth stands can lead to relatively high mortality, but part of it is not necessarily related to wind since it occurs as standing dead trees. Differences in the amount of damage with tree size and species have been found and could be used to reduce wind damage. Conclusions: Approaches to minimize wind damage in ecosystem management can be designed using existing knowledge. However, using windthrow as a template to design management strategies would prove more complex.


2017 ◽  
Vol 7 (1-2) ◽  
pp. 73-107
Author(s):  
Orsolya Perger ◽  
Curtis Rollins ◽  
Marian Weber ◽  
Wiktor Adamowicz ◽  
Peter Boxall

Sign in / Sign up

Export Citation Format

Share Document