Biodiversity implications of changes in the quantity of dead organic matter in managed forests

1996 ◽  
Vol 4 (3) ◽  
pp. 238-265 ◽  
Author(s):  
B. Freedman ◽  
V. Zelazny ◽  
D. Beaudette ◽  
T. Fleming ◽  
G. Johnson ◽  
...  

Dead organic matter is an important structural and functional element in natural forests, but its quantity, quality, and spatial distribution are greatly modified by intensive harvesting and management through forestry. From the perspective of conflicts with biodiversity, the most important changes are associated with reductions in the abundance of snags, cavity trees, and coarse-woody debris, all of which are well known as critical habitat elements for a wide range of indigenous species. Changes in the depth and quality of the forest floor of managed stands are also important for some species and guilds of wildlife. Resolution of this conflict between forestry and biodiversity will require the design and implementation of management systems that accommodate the critical habitat qualities associated with dead organic matter, particularly with large-dimension deadwood and cavities. This goal may be most effectively achieved by an integrated strategy that involves (i) basing forest-management planning on shifting-mosaic habitat models of stand harvesting and replacement, designed to ensure a continuous availability of sufficient areas of stands old enough to sustain habitat features associated with dead organic matter, along with (ii) the provision of protected areas of mature and older growth forest, associated with riparian buffers, deer yards, and nonharvested ecological reserves and other kinds of protected areas. The protected areas are necessary to accommodate those elements of biodiversity that cannot tolerate the conditions of managed stands.Key words: biodiversity, managed forests, plantations, old-growth forests, coarse-woody debris, cavity trees, snags.

Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.


2015 ◽  
Vol 76 (4) ◽  
pp. 322-330 ◽  
Author(s):  
Konrad Skwarek ◽  
Szymon Bijak

Abstract Dead wood plays an important role for the biodiversity of forest ecosystems and influences their proper development. This study assessed the amount of coarse woody debris in municipal forests in Warsaw (central Poland). Based on the forest site type, dominant tree species and age class, we stratified all complexes of the Warsaw urban forests in order to allocate 55 sample plots. For these plots, we determined the volume of dead wood including standing dead trees, coarse woody debris and broken branches as well as uprooted trees. We calculated the amount of dead wood in the distinguished site-species-age layers and for individual complexes. The volume of dead matter in municipal forests in Warsaw amounted to 38,761 m3, i.e. 13.7 m3/ha. The obtained results correspond to the current regulations concerning the amount of dead organic matter to be left in forests. Only in the Las Bielański complex (northern Warsaw) volume of dead wood is comparable to the level observed in Polish national parks or nature reserves, which is still far lower than the values found for natural forests. In general, municipal forests in Warsaw stand out positively in terms of dead wood quantity and a high degree of variation in the forms and dimensions of dead wood.


Author(s):  
Dennis Knight ◽  
Daniel Tinker

In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of mineral soil organic matter. Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, and make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes much of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.


2018 ◽  
Vol 48 (4) ◽  
pp. 399-411 ◽  
Author(s):  
Praveen Kumar ◽  
Han Y.H. Chen ◽  
Sean C. Thomas ◽  
Chander Shahi

Although the importance of coarse woody debris (CWD) to understory species diversity has been recognized, the combined effects of CWD decay and substrate species on abundance and species diversity of epixylic vegetation have received little attention. We sampled a wide range of CWD substrate species and decay classes, as well as forest floors in fire-origin boreal forest stands. Percent cover, species richness, and evenness of epixylic vegetation differed significantly with both CWD decay class and substrate species. Trends in cover, species richness, and evenness differed significantly between nonvascular and vascular taxa. Cover, species richness, and species evenness of nonvascular species were higher on CWD, whereas those of vascular plants were higher on the forest floor. Epixylic species composition also varied significantly with stand ages, overstory compositions, decay classes, substrate species, and their interactions. Our findings highlight strong interactive influences of decay class and substrate species on epixylic plant communities and suggest that conservation of epixylic diversity would require forest managers to maintain a diverse range of CWD decay classes and substrate species. Because stand development and overstory compositions influence CWD decay classes and substrate species, as well as colonization time and environmental conditions in the understory, our results indicate that managed boreal landscapes should consist of a mosaic of different successional stages and a broad suite of overstory types to support diverse understory plant communities.


1999 ◽  
Vol 29 (12) ◽  
pp. 1926-1934 ◽  
Author(s):  
Matthew D Duvall ◽  
David F Grigal

Coarse woody debris (CWD) chronosequences were developed for managed and unmanaged red pine (Pinus resinosa Ait.) stands across the Great Lakes states. Throughout stand development, there is less CWD in managed than in unmanaged forests, and effects of management are strongest in young forests (0-30 years old). At stand initiation, CWD is 80% lower in managed than unmanaged forests, 20 200 versus 113 200 kg·ha-1, while at 90 years, CWD is 35% lower, 6600 versus 10 400 kg·ha-1. Timber management especially affects snags. In young managed forests, snag biomass is less than 1% of that in unmanaged forests, 150 versus 58 200 kg·ha-1, while log biomass is 80% lower, 5000 versus 22 800 kg·ha-1. This trend continues in mature forests (91-150 years old), where snag biomass is 75% lower in managed than in unmanaged forests, 1700 versus 6400 kg·ha-1. Management has relatively little impact on total log biomass of mature forests but increases the biomass of fresh logs nearly 10-fold, to 1400 versus 150 kg·ha-1. CWD in managed forests is highly variable, primarily related to thinning schedules in individual stands.


2014 ◽  
Vol 71 (5) ◽  
pp. 585-594 ◽  
Author(s):  
Jianfen Guo ◽  
Guangshui Chen ◽  
Jinsheng Xie ◽  
Zhijie Yang ◽  
Yusheng Yang

2017 ◽  
Vol 28 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Steven M. Grodsky ◽  
Christopher E. Moorman ◽  
Sarah R. Fritts ◽  
Joshua W. Campbell ◽  
Clyde E. Sorenson ◽  
...  

Author(s):  
Dennis Knight ◽  
Daniel Tinker

Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of this organic matter. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, which make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes most of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.


2012 ◽  
Vol 131 (5) ◽  
pp. 1411-1422 ◽  
Author(s):  
Olli-Pekka Tikkanen ◽  
Jukka Matero ◽  
Mikko Mönkkönen ◽  
Artti Juutinen ◽  
Jari Kouki

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