The Cost of Achieving Old-Growth Forest Structure

2006 ◽  
Vol 82 (2) ◽  
pp. 240-256 ◽  
Author(s):  
C. A. Montgomery ◽  
G. S. Latta ◽  
D. M. Adams
Keyword(s):  
Forest Structure ◽  
Old Growth ◽  
Old Growth Forest ◽  
The Cost

scholarly journals Recovery of Forest Structure Following Large-Scale Windthrows in the Northwestern Amazon

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 667
Author(s):  
J. David Urquiza Muñoz ◽  
Daniel Magnabosco Marra ◽  
Robinson I. Negrón-Juarez ◽  
Rodil Tello-Espinoza ◽  
Waldemar Alegría-Muñoz ◽  
...  
Keyword(s):  
Forest Structure ◽  
Large Scale ◽  
Tree Mortality ◽  
Basal Area ◽  
Forest Recovery ◽  
Old Growth ◽  
Study Region ◽  
Central Amazon ◽  
Old Growth Forest ◽  
Study Sites

The dynamics of forest recovery after windthrows (i.e., broken or uprooted trees by wind) are poorly understood in tropical forests. The Northwestern Amazon (NWA) is characterized by a higher occurrence of windthrows, greater rainfall, and higher annual tree mortality rates (~2%) than the Central Amazon (CA). We combined forest inventory data from three sites in the Iquitos region of Peru, with recovery periods spanning 2, 12, and 22 years following windthrow events. Study sites and sampling areas were selected by assessing the windthrow severity using remote sensing. At each site, we recorded all trees with a diameter at breast height (DBH) ≥ 10 cm along transects, capturing the range of windthrow severity from old-growth to highly disturbed (mortality > 60%) forest. Across all damage classes, tree density and basal area recovered to >90% of the old-growth values after 20 years. Aboveground biomass (AGB) in old-growth forest was 380 (±156) Mg ha−1. In extremely disturbed areas, AGB was still reduced to 163 (±68) Mg ha−1 after 2 years and 323 (± 139) Mg ha−1 after 12 years. This recovery rate is ~50% faster than that reported for Central Amazon forests. The faster recovery of forest structure in our study region may be a function of its higher productivity and adaptability to more frequent and severe windthrows. These varying rates of recovery highlight the importance of extreme wind and rainfall on shaping gradients of forest structure in the Amazon, and the different vulnerabilities of these forests to natural disturbances whose severity and frequency are being altered by climate change.

Birds in patches of old-growth ash forest, in a matrix of younger forest

1998 ◽  
Vol 4 (2) ◽  
pp. 111 ◽  
Author(s):  
Richard H. Loyn
Keyword(s):  
Forest Structure ◽  
Patch Size ◽  
Forest Birds ◽  
Old Growth ◽  
Forest Patches ◽  
Bird Abundance ◽  
Old Growth Forest ◽  
Generalized Linear Modelling ◽  
Mountain Ash ◽  
Context Variables

Birds were studied at 57 sites in Mountain Ash forests in the Central Highlands of Victoria, Australia in spring and summer 1995/96. The sites represented 41 patches of old-growth forest (up to 390 ha in size) in a matrix of regrowth mostly from severe fires in 1939 (57 years previously), with multiple sites in the four largest patches of old-growth and eight sites in 1939 regrowth. Relative bird abundance was assessed by an area-search technique. Generalized linear modelling was used to develop predictive models by regressing abundance of groups of bird species against patch size, isolation and some basic habitat and context variables. Total bird abundance (of all species combined) tended to be higher in old-growth patches than in 1939 regrowth, but not significantly. There was no trend in total abundance with patch size or isolation. Fruit-eating birds tended to be commonest in small patches. Bark-foragers and uncommon birds favoured large patches, though the latter were most common in 1939 regrowth. More variation was explained by habitat and context variables such as aspect, altitude and forest structure. Unevenaged forest structure was often associated with small patches. It was concluded that old-growth forest patches can have similar values per hectare for forest birds whether they are large or small. The regrowth forest matrix appears to protect small patches from factors which reduce densities of forest birds in small forest patches in farmland. The data support the current policy of retaining all old-growth ash forest patches. A range of factors should be considered in selecting regrowth stands of various sizes to regrow as old forest of the future, including their intrinsic potential to develop particular habitats and produce a mix of forest stuctures in the landscape.

Deadwood occurrence and forest structure as indicators of old-growth forest conditions in Mediterranean mountainous ecosystems

Ecoscience ◽  
2012 ◽  
Vol 19 (4) ◽  
pp. 344-355 ◽  
Author(s):  
Fabio Lombardi ◽  
Bruno Lasserre ◽  
Gherardo Chirici ◽  
Roberto Tognetti ◽  
Marco Marchetti
Keyword(s):  
Forest Structure ◽  
Old Growth ◽  
Old Growth Forest ◽  
Forest Conditions

Stand-level spatial dependence in an old-growth Jeffrey pine – mixed conifer forest, Sierra San Pedro Mártir, Mexico

2010 ◽  
Vol 40 (9) ◽  
pp. 1803-1814 ◽  
Author(s):  
Danny L. Fry ◽  
Scott L. Stephens
Keyword(s):  
Spatial Pattern ◽  
Forest Structure ◽  
Forest Ecosystems ◽  
Conifer Forest ◽  
Spatial Correlations ◽  
Mixed Conifer ◽  
Old Growth ◽  
Jeffrey Pine ◽  
Old Growth Forest ◽  
Mixed Conifer Forest

Descriptions of spatial patterns are important components of forest ecosystems, providing insights into functions and processes, yet basic spatial relationships between forest structures and fuels remain largely unexplored. We used standardized omnidirectional semivariance modeling to examine the spatial pattern of fuels and forest structure measured in a systematic nested plot grid covering 144 ha. Forest structure variables were spatially dependent at scales ranging from 62 to 572 m. Cross-variograms of fuels and forest structure showed both positive and negative correlations, ranging from 0.04 to 0.67. Notably, fine fuels were correlated positively and negatively with forest structure variables of white fir ( Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) and Jeffrey pine ( Pinus jeffreyi Balf.), respectively. Old-growth Jeffrey pine – mixed conifer forest within the study area exhibited both identifiable spatial correlations and high stand-level spatial heterogeneity, as demonstrated by the influence of outliers on the underlying spatial pattern. The spatial dependency of fuels with species-specific variables suggests that less common species may have a large influence in the characterization of forest attributes and that fuel classifications may be improved by accounting for the spatial distributions of overstory species. Spatial correlations have many applications to forest management, including the classification and mapping of forest structure, establishing guidelines for fuel treatments, and restoration of old-growth forest ecosystems.

scholarly journals Old‐growth forest structure in a low‐productivity hypermaritime rainforest in coastal British Columbia, Canada

Ecosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Kira M. Hoffman ◽  
Brian M. Starzomski ◽  
Ken P. Lertzman ◽  
Ian J. W. Giesbrecht ◽  
Andrew J. Trant
Keyword(s):  
British Columbia ◽  
Forest Structure ◽  
Old Growth ◽  
Old Growth Forest ◽  
Coastal British Columbia

scholarly journals Forest structural parameters and aboveground biomass in old-growth and secondary forests along an elevational gradient in Mexico

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martina Alrutz ◽  
Jorge Antonio Gómez Díaz ◽  
Ulf Schneidewind ◽  
Thorsten Krömer ◽  
Holger Kreft
Keyword(s):  
Climate Change ◽  
Forest Structure ◽  
Aboveground Biomass ◽  
Basal Area ◽  
Elevational Gradient ◽  
Stem Density ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests

Background: Tropical montane forests are important reservoirs of carbon and biodiversity but are threatened by deforestation and climate change. It is important to understand how forest structure and aboveground biomass change along gradients of elevation and succession. Questions: What are the interactive effect of elevation and two stages of succession on forest structure parameters? Studied species: Tree communities. Study site and dates: Cofre de Perote, Veracruz, Mexico. August to December 2015. Methods: We studied four sites along an elevational gradient (500, 1,500, 2,500, and 3,500 m). At each elevation and each forest type, we established five 20 × 20 m plots (n = 40 plots). Within each plot, we measured stem density, mean diameter at breast height (dbh), and tree height and derived basal area and aboveground biomass (AGB). Results: AGB peaked at 2,500 m and was significantly related to elevation and succession, with higher values in old-growth forests than in secondary forests at higher altitudes. Lower values of mean dbh and basal area were found at higher elevations. At the lowest elevation, both successional stages had the same values of stem density and AGB. At both lower elevations, secondary forests had higher values of dbh and basal area. There were high biomass stocks in the old-growth forest at 2,500 and 3,500 m. Conclusions: Old-growth forests at higher elevations are threatened by deforestation, consequently these remaining fragments must be preserved because of their storage capacity for biomass and their ability to mitigate climate change.

scholarly journals Minimizing the Cost of Stand Level Management for Older Forest Structure in Western Oregon

2004 ◽  
Vol 19 (4) ◽  
pp. 221-231 ◽  
Author(s):  
Greg Latta ◽  
Claire A. Montgomery
Keyword(s):  
Forest Structure ◽  
Opportunity Cost ◽  
Random Search ◽  
Cost Effective ◽  
Active Management ◽  
Stand Age ◽  
Individual Tree ◽  
Old Growth Forest ◽  
Wide Range ◽  
The Cost

Abstract The area of old-growth forest in the Pacific Northwest is estimated to have declined dramatically from historical levels. Active management involving repeated thinning that leaves substantially fewer trees than a typical commercial thin has been proposed as a way to speed the development of older forest structure in the region. This study uses a random search heuristic and an individual tree simulation model, ORGANON, to search for cost-effective old forest management regimes for a wide range of stand types that occur on private land in western Oregon. The regimes were designed to meet older forest structural criteria, as defined by the Oregon Department of Forestry, for 30 years prior to clearcut harvest. The opportunity cost of managing for older forest structure was estimated for each stand type as the value of forgone timber production under maximum net present value management. Opportunity cost was found to be positively correlated with site quality, stand age, and stocking. Cost-effective management for older forest structure is important because the lower the cost of conservation, the more likely it will occur. West. J. Appl. For. 19(4):221–231.

scholarly journals Effects of forest disturbance and regeneration on tree species composition and traits in DR Congo

2021 ◽  
Author(s):  
Jonas Depecker ◽  
Justin Anio Asimonyio ◽  
Ronald Miteho ◽  
Yves Hatangi ◽  
Jean-Leon Kambale ◽  
...  
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Forest Structure ◽  
Tree Species ◽  
Anthropogenic Disturbance ◽  
Congo Basin ◽  
Old Growth ◽  
Tree Species Composition ◽  
Old Growth Forest ◽  
The Impact

Despite their key role in biodiversity conservation, forests of the Congo Basin are increasingly threatened by human activities. Whereas deforestation is very conspicuous, it remains challenging to monitor the impact of forest degradation under a more or less intact canopy. Likewise, the outcomes of forest regeneration following agricultural abandonment remain poorly studied in the Congo Basin. Here, we surveyed 125 vegetation quadrats across 25 forest inventory plots in the Yangambi region, and based on historical land-use maps. We aimed to assess both the impact of anthropogenic disturbance and forest recovery on tree species diversity, tree functional traits, community composition, canopy cover, and forest structure, as compared to undisturbed old-growth forest. We found that undisturbed old-growth forest harboured more tree individuals, particularly individuals with a smaller diameter, as well as species with a higher wood density when compared to both disturbed old-growth and regrowth forest. Moreover, species diversity was highest in disturbed old-growth forest. Tree species composition was significantly different between undisturbed old-growth forest and the other two forest categories. Our findings indicate that anthropogenic disturbance results in a degraded forest structure and may reduce the forest's ability to store carbon. Whereas species diversity recovered 60 years after agricultural abandonment, species composition remained different from undisturbed old-growth forest. Our study illustrates the need for more extensive vegetation surveys in the Congo Basin in order to quantify the effects of human disturbance under a closed canopy.

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