scholarly journals AN ASSESSMENT OF RETENTION TREES IN HYLOCOMIOSA FOREST TYPE IN SOUTHERN LATVIA

Author(s):  
Inga STRAUPE ◽  
Līga LIEPA

In Latvia the forest legislation requires that at least five living trees must be retained per hectare after clear-cutting. It is known that retention trees significantly increase the biodiversity in production forest landscape. After clear-cutting retention trees function as habitats for various lichens, mosses, insects, fungi and birds. Over time retention trees are incorporated into the young forests stand and provide presence of old trees, which is necessary for many endangered and rare species. After the death, these trees turn into coarse woody debris which is an essential habitat and feeding source for many taxa. However, the conservation and mortality of the retention trees has not been studied extensively because this approach has been established recently. The aim of this study was to evaluate development of the retention trees in Hylocomiosa type of forests in Southern Latvia. In total 12 young forest stands were surveyed in 2009 and 2015. The total area – 13.7 ha, on average forest stand size varies from 0.5 to 3.0 ha. All the studied sites were harvested in 2002, 2004, 2006 and 2008. All measurements of tree species, height, and diameter and defoliation class assessed and the status of tree (growing tree, coarse woody debris – snags, stems and downed logs) was indicated. Results show that after the studied period of seven years 24 retention trees died. Average level of the tree mortality is 15 %. The mortality level of Scots pine retention trees is 5.8 %, for aspen – 50 % and that for birch – 92.3 %. An average it is 8.5 green retention trees per 1 ha of young stand (22.9 m3 ha-1). On average 2.3 pieces coarse woody debris are per 1 ha of young stand (3.52 m3 ha-1), mostly - aspen wood (2.4 m3 ha-1). Woody debris of the young stands is divided to the first 4 decay levels according to classification (Stokland et al., 2001). 50 % of the listed woody debris is related to the 3rd decay level which means that woody debris is moderately decomposed.


2008 ◽  
Vol 32 (2) ◽  
pp. 53-59 ◽  
Author(s):  
Jason R. Applegate

Abstract An inventory of down woody materials (DWM) was conducted on Fort A.P. Hill, Virginia, to develop a baseline of DWM abundance and distribution to assist in wildland fire management. Estimates of DWM are necessary to develop accurate assessments of wildfire hazard, model wildland fire behavior, and establish thresholds for retaining DWM, specifically CWD (coarse woody debris), as a structural component of forest ecosystems. DWM were sampled by forest type and structure class using US Forest Service, Forest Inventory and Analysis (FIA) field procedures. DWM averaged 12–16 tn/ac depending on forest cover type and structure class. Coarse woody debris (CWD) averaged 2.7–13.0 tn/ac depending on forest cover type and structure class. CWD comprised more than 70% of DWM across all forest cover types and structure classes. Fine woody debris (FWD) averaged 0.05–3.2 tn/ac depending on fuel hour class, forest cover type, and structure class. DWM was consistently higher in mature (sawtimber) forests than in young (poletimber) forests across all forest cover types, attributed to an increased CWD component of DWM. The variability associated with DWM suggests that obtaining robust estimates of CWD biomass will require a higher sampling intensity than FWD because of its nonuniform distribution in forest systems. FIA field procedures for tallying and quantifying DWM were practical, efficient, and, subsequently, included as permanent metrics in Fort A.P. Hill's Continuous Forest Inventory program.



1994 ◽  
Vol 24 (7) ◽  
pp. 1317-1329 ◽  
Author(s):  
Brian C. McCarthy ◽  
Ronald R. Bailey

Coarse woody debris (CWD) is integral to the functioning and productivity of forested ecosystems. Standing snags and large logs on the forest floor affect soil processes, soil fertility, hydrology, and wildlife microhabitat. Few data are available pertaining to the distribution and abundance of CWD in the managed hardwood forests of the central Appalachians. We surveyed 11 stands, at various stages of development (succession) after clear-cutting (<2, 15–25, 65–90, >100 years old), to evaluate the density, volume, and biomass of trees, snags, and logs under the local forest management regime. As expected, density, volume, and biomass of CWD (stems ≥2.5 cm diameter) were greatest in young stands (<2 years old) immediately following clear-cutting; the vast majority of CWD existed as relatively labile, small-diameter, low decay state logging slash. Young stands retained a few large logs in advanced decay states but observations suggest that these elements were often disturbed (i.e., crushed) by logging equipment during the harvest process. Crushed logs do not function ecologically in the same capacity as large intact logs. A marked decline in CWD was observed in young pole stands (15–25 years old) as slash decomposed. These stands were characterized by a high density of young hardwood stump sprouts in the overstory while maintaining a moderate amount of CWD in middle size and decay states on the forest floor. More mature hardwood stands (65–90 years old) generally exhibited a decrease in live-stem density and an increase in basal area, accompanied by a slight increase in CWD. Commercial thinning presumably limits the contribution of large CWD to the forest floor. This was most clearly evident in the oldest stands (>100 years old) where large CWD was not widely observed. A striking feature across all stands was the near absence of logs in large size classes (>65 cm diameter) and a paucity of logs in mid to late decay stages. We discuss our data in the context of hardwood forest structure and management in the central Appalachians.



1994 ◽  
Vol 24 (10) ◽  
pp. 1989-1996 ◽  
Author(s):  
Glenn H. Stewart ◽  
Larry E. Burrows

The volume, biomass, and carbon and nitrogen content of coarse woody debris were measured on three 1-ha reference plots in old-growth Nothofagusfusca (Hook. f.) Oerst.–Nothofagusmenziesii (Hook. f.) Oerst. forest on the South Island of New Zealand. Two decay sequences for logs and one for standing dead trees (snags) were recognised from two-way indicator species analysis (TWINSPAN) of up to 30 variables related to physical characteristics and structural integrity. Wood volume (up to 800 m3•ha−1) and biomass were high (up to 300 Mg•ha−1), and the inside-out decay sequence from heartwood to sapwood was unusual compared with that of other temperate hardwood forests. Coarse woody debris represented significant carbon and nitrogen pools, with ca. 150 Mg•ha−1 and 370 kg•ha−1, respectively, in one stand. The coarse woody debris component of these broad-leaved evergreen hardwood forests was much higher than that reported for other temperate hardwood forests and approaches that of many northern hemisphere conifer forests. The large coarse woody debris pools are discussed in relation to live stand biomass, natural disturbances and tree mortality, and decomposition processes.



2010 ◽  
Vol 26 (4) ◽  
pp. 467-471 ◽  
Author(s):  
Lisa B. Kissing ◽  
Jennifer S. Powers

The ecological importance of trees lasts much longer than their life spans. Standing dead trees (snags) and fallen trunks and branches are an important component of above-ground carbon stocks and nutrient reserves, provide habitat for wildlife, and interact with disturbance regimes (e.g. by serving as fuel for fires) (Clark et al. 2002, Harmon et al. 1986, Pyle et al. 2008). Despite these diverse functions, woody debris stocks remain poorly quantified in tropical forests in general (Brown 1997), and in tropical dry forests in particular (Harmon et al. 1995). More empirical studies of the patterns of woody debris and processes that control its dynamics are needed to understand its role in global biogeochemical cycles and for ecosystem simulation models, many of which do not represent coarse woody debris (CWD) as a separate pool (Cornwell et al. 2009).



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.



2002 ◽  
Vol 32 (5) ◽  
pp. 768-778 ◽  
Author(s):  
Olga N Krankina ◽  
Mark E Harmon ◽  
Yuri A Kukuev ◽  
Rudolf F Treyfeld ◽  
Nikolai N Kashpor ◽  
...  

To assess regional stores of coarse woody debris (CWD) in seven major forest regions of Russia, we combined data collected as part of the routine forest inventory with measurements in 1044 sample plots and the results of density sampling of 922 dead trees. The stores of CWD in the western part of Russia (St. Petersburg, Central, Khanty-Mansi, and Novosibirsk regions) were on average lower (14–20 m3/ha or 4.0–5.8 Mg/ha) than in the East Siberian and Far Eastern regions (40–51 m3/ha or 11.0–14.4 Mg/ha). The difference in CWD stores was particularly large between young forests in two western regions (2.4 Mg/ha in St. Petersburg and 3.4 Mg/ha in the Central region) and in the east (20.4–24.4 Mg/ha). This difference is associated with the prevailing disturbance type: clear-cut harvest in western Russia and natural disturbances in the east. Analysis of variance in CWD stores indicates that region, dominant species, forest age group, productivity class, and interactions of these factors explain 87–88% of the total variance and the strongest effects are for age group and region. Lower stores of CWD within the intensively managed forest regions suggest that further expansion of forest use in many regions of Russia may reduce regional stores of CWD and carbon.



Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1330
Author(s):  
Angelo T. Filicetti ◽  
Ryan A. LaPointe ◽  
Scott E. Nielsen

Restoring anthropogenic footprints to pre-disturbance conditions or minimizing their long-term impacts is an important goal in conservation. Many footprints, particularly if left alone, have wide-ranging effects on biodiversity. In Canada, energy exploration footprints result in forest dissection and fragmentation contributing to declines in woodland caribou. Developing cost effective strategies to restore forests and thus conserving the woodland caribou habitat is a conservation priority. In this study, we compared the effects of wildfire and local variation in the amount of residual woody debris on natural regeneration in jack pine on exploratory well pads in Alberta’s boreal forest. Specifically, we investigated how footprint size, fire severity (overstory tree mortality), ground cover of fine and coarse woody debris, and adjacent stand characteristics (i.e., height, age, and cover), affected tree regeneration densities and height using negative binomial count and linear models (Gaussian), respectively. Regeneration density was 30% higher on exploratory well pads than adjacent forests, increased linearly with fire severity on the exploratory well pads (2.2% per 1% increase in fire severity), but non-linearly in adjacent forests (peaking at 51,000 stems/ha at 72% fire severity), and decreased with amount of woody debris on exploratory well pads (2.7% per 1% increase in woody debris cover). The height of regenerating trees on exploratory well pads decreased with fire severity (0.56 cm per 1% increase in fire severity) and was non-linearly related to coarse woody debris (peaking at 286 cm at 9.4% coarse woody debris cover). Heights of 3 and 5 m on exploratory well pads were predicted by 13- and 21-years post-fire, respectively. Our results demonstrate that wildfires can stimulate natural recovery of fire-adapted species, such as jack pine, on disturbances as large as exploratory well pads (500–1330 m2) and that the type and amount of woody debris affects these patterns.



2011 ◽  
Vol 347-353 ◽  
pp. 107-111
Author(s):  
Fei Wang ◽  
Qiu Liang Zhang ◽  
Xiao Mei Li ◽  
Chun Sheng Bao ◽  
Xiao Wei Gao

Coarse woody debris (CWD) is composed of dry wood, fallen wood and large branches, and it is an important element for structure and function in forest ecosystems. In this paper, we studied the characteristics of coarse woody debris (CWD) of natural Larix gmelinii forests with different ages in Daxing’anling Mountains. The results show that (1) the CWD volumes in near-mature, middle-age and young forests are 88.55 m3•hm-2, 52.07 m3•hm-2 and 3.96 m3•hm-2, respectively; and their biomasses are 52.96 t•hm-2, 36.22 t•hm-2 and 2.35t•hm-2, respectively. Which indicate that the CWD volumes and biomasses increase with forest ages addition; (2) The CWD volume and biomass follow normal distribution in middle and near-mature forest; (3) the CWD volume and biomass decrease with forest age increasing within decay classes I and II, whereas increase in decay classes III, IVand V; (4) the volume of middle-age and young forests present a near normal distribution with decay class increasing.



Ecoscience ◽  
1998 ◽  
Vol 5 (4) ◽  
pp. 551-560 ◽  
Author(s):  
Brian Palik ◽  
Stephen Golladay ◽  
Charles Goebel ◽  
Brad W. Taylor


1995 ◽  
Vol 3 (3-4) ◽  
pp. 230-261 ◽  
Author(s):  
Phillip G. deMaynadier ◽  
Malcolm L. Hunter Jr.

Questions about the compatibility of forest harvesting practices and conservation of biological diversity are largely driven by concerns that habitat quality for many species may be degraded in intensively managed forest landscapes. We review the literature on relationships between common forest harvesting practices and the distribution and abundance of amphibians, a group that has attracted considerable attention in recent years because of their potential ecological importance in forest ecosystems and because of reports of widespread population declines. Clear-cut harvesting generally has negative short-term impacts on local amphibian populations, especially salamanders. An analysis of the results of 18 studies that examined the effects of clear-cutting on amphibians yielded a 3.5-fold median difference in abundance of amphibians on controls over clear-cuts. However, research on the influence of forest age suggests that the long-term effects of forest harvesting on amphibians are variable, and for many species these effects can be mitigated if regeneration practices leave adequate microhabitat structure intact. In contrast, long-term effects can be significant in forest plantations, which are often associated with intensive site preparations and stand management practices that modify levels of coarse woody debris and other microhabitats. Other forest practices reviewed for their effect on amphibians include prescribed fire, logging roads, and streamside harvesting. We discuss problems commonly encountered in the experimental design and measurement of forest amphibian populations, including a notable lack of pretreatment data, and outline several aspects of amphibian–forestry relationships in need of further research. Management recommendations relevant to conserving upland and riparian zone amphibian habitat during forest harvesting are offered.Key words: amphibians, clear-cutting, coarse woody debris, forest management, logging roads, plantations, prescribed fire, riparian, succession.



Sign in / Sign up

Export Citation Format

Share Document