Historical range of variability in live and dead wood biomass: a regional-scale simulation study

2007 ◽  
Vol 37 (11) ◽  
pp. 2349-2364 ◽  
Author(s):  
Etsuko Nonaka ◽  
Thomas A. Spies ◽  
Michael C. Wimberly ◽  
Janet L. Ohmann
Keyword(s):  
Forest Structure ◽  
Dead Wood ◽  
Stand Structure ◽  
Structural Characteristics ◽  
Regional Scale ◽  
Natural Disturbance ◽  
Wood Biomass ◽  
Historical Range Of Variability ◽  
Coarse Filter ◽  
Historical Range

The historical range of variability (HRV) in landscape structure and composition created by natural disturbance can serve as a general guide for evaluating ecological conditions of managed landscapes. HRV approaches to evaluating landscapes have been based on age-classes or developmental stages, which may obscure variation in live and dead stand structure. Developing the HRV of stand structural characteristics would improve the ecological resolution of this coarse-filter approach to ecosystem assessment. We investigated HRV in live and dead wood biomass in the regional landscape of the Oregon Coast Range by integrating stand-level biomass models and a spatially explicit fire simulation model. We simulated historical landscapes of the region for 1000 years under pre-Euro-American settlement fire regimes and calculated biomass as a function of disturbance history. The simulation showed that live and dead wood biomass historically varied widely in time and space. The majority of the forests historically contained 500–700 Mg·ha–1 (50–70 kg·m–2) of live wood and 50–200 Mg·ha–1 (5–20 kg·m–2) of dead wood. The current distributions are more concentrated in much smaller amounts for both biomass types. Although restoring the HRV of forest structure is not necessarily a management goal for most landowners and managing agencies, departure from the reference condition can provide relative measure to evaluate habitat conditions for managers seeking to use forest structure as a means to maintain or restore ecosystem and species diversity.

scholarly journals Assessing the role of natural disturbance and forest management on dead wood dynamics in mixed-species stands of central Maine, USA

2016 ◽  
Vol 46 (9) ◽  
pp. 1092-1102 ◽  
Author(s):  
Joshua J. Puhlick ◽  
Aaron R. Weiskittel ◽  
Shawn Fraver ◽  
Matthew B. Russell ◽  
Laura S. Kenefic
Keyword(s):  
Forest Management ◽  
Dead Wood ◽  
Natural Disturbance ◽  
Site Quality ◽  
Stand Development ◽  
Wood Biomass ◽  
Clear Cut ◽  
Live Tree ◽  
Over Time

Dead wood pools are strongly influenced by natural disturbance events, stand development processes, and forest management activities. However, the relative importance of these influences can vary over time. In this study, we evaluate the role of these factors on dead wood biomass pools across several forest management alternatives after 60 years of treatment on the Penobscot Experimental Forest in central Maine, USA. After accounting for variation in site quality, we found significant differences in observed downed coarse woody material (CWM; ≥7.6 cm small-end diameter) and standing dead wood biomass among selection, shelterwood, and commercial clear-cut treatments. Overall, total dead wood biomass was positively correlated with live tree biomass and was negatively correlated with the average wood density of nonharvest mortality. We also developed an index of cumulative harvest severity, which can be used to evaluate forest attributes when multiple harvests have occurred within the same stand over time. Findings of this study highlight the dynamic roles of forest management, stand development, and site quality in influencing dead wood biomass pools at the stand level and underscore the potential for various outcomes from the same forest management treatment applied at different times in contrasting stands.

Stand composition and structure of the boreal mixedwood and epigaeic arthropods of the Ecosystem Management Emulating Natural Disturbance (EMEND) landbase in northwestern Alberta

2004 ◽  
Vol 34 (2) ◽  
pp. 417-430 ◽  
Author(s):  
Timothy T Work ◽  
David P Shorthouse ◽  
John R Spence ◽  
W Jan A Volney ◽  
David Langor
Keyword(s):  
Forest Management ◽  
Boreal Forests ◽  
Biological Diversity ◽  
Stand Structure ◽  
Natural Disturbance ◽  
Structural Features ◽  
Conservation Strategies ◽  
Coarse Filter ◽  
Composition And Structure ◽  
Coarse Woody Material

Conservation of biological diversity under the natural disturbance model of boreal forest management relies on the assumption that natural mosaics of stand composition and structure can be adequately recreated through forest management activities. Maintaining compositional and structural features that provide adequate habitat for species within managed stands is the basis of coarse-filter conservation strategies. Here we test the effect of stand composition and stand structure on the epigaeic arthropod fauna from four boreal mixedwood cover types in western Canada. We observed differences in epigaeic community composition and species-specific associations among each of the four cover types. Differences in the carabid fauna between cover types were defined by relative abundance of carabid species associated specifically with moss cover, forb cover, and of coarse woody material, rather than unique, stand-specific species compositions of the overstory. Cover-type differences were less apparent among the comparatively species-rich spider assemblages largely because of their low abundance in undisturbed stands. For the effective conservation of all species, our results suggest that coarse-filter management of mixedwood boreal forests must incorporate structural features beyond overstory canopy composition. Our analyses also suggest that activities directed at managing the amount of coarse woody material on the ground and understory plant composition, perhaps through variable retention harvesting, is a logical first step.

Stand-Level Forest Structure and Avian Habitat: Scale Dependencies in Predicting Occurrence in a Heterogeneous Forest

2008 ◽  
Vol 54 (1) ◽  
pp. 36-46
Author(s):  
Katherine Manaras Smith ◽  
William S. Keeton ◽  
Therese M. Donovan ◽  
Brian Mitchell
Keyword(s):  
Forest Structure ◽  
Stand Structure ◽  
Site Occupancy ◽  
Territory Size ◽  
Weight Of Evidence ◽  
Habitat Models ◽  
Point Counts ◽  
Forest Stand Structure ◽  
Habitat Scale

Abstract We explored the role of stand-level forest structure and spatial extent of forest sampling in models of avian occurrence in northern hardwood-conifer forests for two species: black-throated blue warbler (Dendroica caerulescens) and ovenbird (Seiurus aurocapillus). We estimated site occupancy from point counts at 20 sites and characterized the forest structure at these sites at three spatial extents (0.2, 3.0, and 12.0 ha). Weight of evidence was greatest for habitat models using forest stand structure at the 12.0-ha extent and diminished only slightly at the 3.0-ha extent, a scale that was slightly larger than the average territory size of both species. Habitat models characterized at the 0.2-ha extent had low support, yet are the closest in design to those used in many of the habitat studies we reviewed. These results suggest that the role of stand-level vegetation may have been underestimated in the past, which will be of interest to land managers who use habitat models to assess the suitability of habitat for species of concern.

Is the END (emulation of natural disturbance) a new beginning? A critical analysis of the use of fire regimes as the basis of forest ecosystem management with examples from the Canadian western Cordillera

2016 ◽  
Vol 24 (3) ◽  
pp. 233-243 ◽  
Author(s):  
Chris Stockdale ◽  
Mike Flannigan ◽  
Ellen Macdonald
Keyword(s):  
Forest Management ◽  
Ecosystem Management ◽  
Forest Structure ◽  
Fire Regime ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Disturbance Regime ◽  
Ecological Processes ◽  
High Severity ◽  
Management Actions

As our view of disturbances such as wildfire has shifted from prevention to recognizing their ecological necessity, so too forest management has evolved from timber-focused even-aged management to more holistic paradigms like ecosystem-based management. Emulation of natural disturbance (END) is a variant of ecosystem management that recognizes the importance of disturbance for maintaining ecological integrity. For END to be a successful model for forest management we need to describe disturbance regimes and implement management actions that emulate them, in turn achieving our objectives for forest structure and function. We review the different components of fire regimes (cause, frequency, extent, timing, and magnitude), we describe low-, mixed-, and high-severity fire regimes, and we discuss key issues related to describing these regimes. When characterizing fire regimes, different methods and spatial and temporal extents result in wide variation of estimates for different fire regime components. Comparing studies is difficult as few measure the same components; some methods are based on the assumption of a high-severity fire regime and are not suited to detecting mixed- or low-severity regimes, which are critical to END management, as this would affect retention in harvested areas. We outline some difficulties with using fire regimes as coarse filters for forest management, including (i) not fully understanding the interactions between fire and other disturbance agents, (ii) assuming that fire is strictly an exogenous disturbance agent that exerts top-down control of forest structure while ignoring numerous endogenous and bottom-up feedbacks on fire effects, and (iii) assuming by only replicating natural disturbance patterns we preserve ecological processes and vital ecosystem components. Even with a good understanding of a fire regime, we would still be challenged with choosing the temporal and spatial scope for the disturbance regime we are trying to emulate. We cannot yet define forest conditions that will arise from variations in disturbance regime; this then limits our ability to implement management actions that will achieve those conditions. We end by highlighting some important knowledge gaps about fire regimes and how the END model could be strengthened to achieve a more sustainable form of forest management.

Rehabilitating boreal forest structure and species composition in Finland through logging, dead wood creation and fire: The EVO experiment

2007 ◽  
Vol 250 (1-2) ◽  
pp. 77-88 ◽  
Author(s):  
I. Vanha-Majamaa ◽  
S. Lilja ◽  
R. Ryömä ◽  
J.S. Kotiaho ◽  
S. Laaka-Lindberg ◽  
...  
Keyword(s):  
Species Composition ◽  
Boreal Forest ◽  
Forest Structure ◽  
Dead Wood

scholarly journals Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds

2019 ◽  
Vol 11 (12) ◽  
pp. 1447 ◽  
Author(s):  
Frederic Brieger ◽  
Ulrike Herzschuh ◽  
Luidmila A. Pestryakova ◽  
Bodo Bookhagen ◽  
Evgenii S. Zakharov ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Structure ◽  
Stand Structure ◽  
Structural Information ◽  
Carbon Sink ◽  
Local Maximum ◽  
Window Size ◽  
Point Clouds ◽  
Percentage Error ◽  
Individual Tree

Forest structure is a crucial component in the assessment of whether a forest is likely to act as a carbon sink under changing climate. Detailed 3D structural information about the tundra–taiga ecotone of Siberia is mostly missing and still underrepresented in current research due to the remoteness and restricted accessibility. Field based, high-resolution remote sensing can provide important knowledge for the understanding of vegetation properties and dynamics. In this study, we test the applicability of consumer-grade Unmanned Aerial Vehicles (UAVs) for rapid calculation of stand metrics in treeline forests. We reconstructed high-resolution photogrammetric point clouds and derived canopy height models for 10 study sites from NE Chukotka and SW Yakutia. Subsequently, we detected individual tree tops using a variable-window size local maximum filter and applied a marker-controlled watershed segmentation for the delineation of tree crowns. With this, we successfully detected 67.1% of the validation individuals. Simple linear regressions of observed and detected metrics show a better correlation (R2) and lower relative root mean square percentage error (RMSE%) for tree heights (mean R2 = 0.77, mean RMSE% = 18.46%) than for crown diameters (mean R2 = 0.46, mean RMSE% = 24.9%). The comparison between detected and observed tree height distributions revealed that our tree detection method was unable to representatively identify trees <2 m. Our results show that plot sizes for vegetation surveys in the tundra–taiga ecotone should be adapted to the forest structure and have a radius of >15–20 m to capture homogeneous and representative forest stands. Additionally, we identify sources of omission and commission errors and give recommendations for their mitigation. In summary, the efficiency of the used method depends on the complexity of the forest’s stand structure.

Disturbance history affects dead wood abundance in Newfoundland boreal forests

2006 ◽  
Vol 36 (12) ◽  
pp. 3194-3208 ◽  
Author(s):  
Martin T Moroni
Keyword(s):  
Boreal Forests ◽  
Dead Wood ◽  
Black Spruce ◽  
Woody Debris ◽  
Abies Balsamea ◽  
Natural Disturbance ◽  
Diameter Distribution ◽  
Natural Disturbances ◽  
A Minor ◽  
Almost All

Dead wood (dead standing tree (snag), woody debris (WD), buried wood, and stump) abundance was estimated in Newfoundland balsam fir (Abies balsamea (L.) Mill.) and black spruce (Picea mariana (Mill.) BSP) forests regrown following natural and anthropogenic disturbances. Although harvesting left few snags standing, natural disturbances generated many snags. Most were still standing 2 years after natural disturbance, but almost all had fallen after 33–34 years. Snag abundance then increased in stands aged 86–109 years. Natural disturbances generated little WD 0–2 years following disturbance. Harvesting, however, immediately generated large amounts of WD. Thirty-two to forty-one years following disturbance, most harvesting slash had decomposed, but naturally disturbed sites had large amounts of WD from collapsed snags. Harvested sites contained less WD 32–72 years following disturbance than naturally disturbed sites. Amounts of WD in black spruce regrown following harvesting and fire converged 63–72 years following disturbance, despite significant initial differences in WD quantities, diameter distribution, and decay classes. Abundance of WD increased from sites regrown 32–72 years following disturbance to older sites. Precommercial thinning had a minor impact on dead wood stocks. Stumps contained minor biomass. Buried wood and WD biomass were equivalent at some sites.

Historical Range of Variability

2014 ◽  
Author(s):  
Ellen Wohl
Keyword(s):  
Human Activities ◽  
Environmental Science ◽  
Natural System ◽  
Spatial And Temporal Variability ◽  
Disturbance Regime ◽  
Human Influence ◽  
Historical Range Of Variability ◽  
European Settlement ◽  
Characteristic Behavior ◽  
Historical Range

Historical range of variability (HRV) describes the conditions of a natural system prior to intensive human alteration of that system. In this context, a natural system can be an ecosystem or a particular component of an ecosystem. Ecosystem components can be quite diverse, including the population of a species or geographic range of a species; an aspect of the disturbance regime, such as the frequency, severity, and spatial extent of wildfire or drought; or physicochemical parameters, such as water chemistry. Regardless of the component to which HRV is applied, the intent is to understand the range of variations in relevant parameters in the absence of human influence on the system. With respect to environmental science, deviations from HRV are taken as evidence of human influence on the system under consideration, and resource management is designed to maintain systems within HRV or within a socially preferred range based on HRV. The concept of HRV was initially developed by ecologists working in North America, and it was applied to understanding ecosystem characteristics prior to European settlement of a region. Although HRV was first mentioned in the early to mid-1990s, the idea of using historical conditions as a reference for ecosystem management goes back much further. HRV built on this earlier work by explicitly considering spatial and temporal variability of system components and processes. Systems exhibit variability through time because conditions change in response to disturbances. The concepts of Disturbance Regime and HRV are thus closely coupled. The assumption underlying HRV is that a system exhibits characteristic behavior and complexity when disturbances occur with a characteristic behavior through time. If human activities alter the disturbance regime, the system changes so as to exceed the bounds described by HRV. HRV is now used by scholars in diverse disciplines, and it is sometimes defined for very different time periods. HRV has been used, for example, to refer to variability during the recent past and intensive human alteration of the system. Consequently, it is important to understand the manner in which HRV is being defined in any particular study. HRV is also referred to as range of natural variability and reference variability. Regardless of the phrase used, the underlying concept represents some of the most fundamental questions we can ask in environmental science: What is the natural range of variability in a system, and in what manner have human activities altered this range?

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