scholarly journals Frost Crack Incidence in Northern Hardwood Forests of the Southern Boreal–North Temperate Transition Zone

2008 ◽  
Vol 25 (3) ◽  
pp. 133-138 ◽  
Author(s):  
Julia I. Burton ◽  
Eric K. Zenner ◽  
Lee E. Frelich
Keyword(s):  
Structural Characteristics ◽  
Regional Climate ◽  
Small Diameter ◽  
Basal Area ◽  
Selective Logging ◽  
Tree Level ◽  
Diameter Class ◽  
Northern Hardwood ◽  
Second Growth ◽  
Small Diameter Trees

Abstract Frost cracks are common in northern hardwood stands near their northern range limits. Although they have long been attributed to the regional climate, temperature fluctuations result in surface cracks largely when internal wounds are present. We examined the relationship between the proportion of trees with frost cracks and both tree-level diameter class and stand structural characteristics in primary stands with a history of minimal logging (n = 4) and 67- to 97-year-old second-growth stands subjected to past heavy partial cuts and high grading (n = 8). We hypothesized that frost crack incidence would (1) be greater in the second-growth stands and (2) be associated with differences in structural attributes between the two stand types. High levels of frost cracking in primary stands indicated that cracks are not completely avoidable. However, the proportion of trees with frost cracks was significantly higher in second-growth than primary stands, particularly on small-diameter trees. For example, the odds for frost cracking were 1.66–3.74 times greater in second-growth than in primary stands in the 15-cm diameter class, but were not different in the 45+-cm diameter class. Frost cracking was positively associated with increasing diameter in both stand types. Structural characteristics reflecting tree size, stand basal area, and basal area of hardwoods were positively associated with the proportion of trees with frost cracks in second-growth stands but not in primary stands. Although the basal area of conifers was negatively associated with frost cracking, the effect was likely due to a reduction in hardwood basal area in the vicinity of conifers. We suggest that greater frost crack incidence in second-growth stands is likely a consequence of injuries to residual trees during selective logging.

An individual-tree basal area growth model for black spruce in second-growth peatland stands

1999 ◽  
Vol 29 (5) ◽  
pp. 621-629 ◽  
Author(s):  
Hannu Hökkä ◽  
Arthur Groot
Keyword(s):  
Growth Model ◽  
Black Spruce ◽  
Basal Area ◽  
Random Parameter ◽  
Considerable Change ◽  
Tree Level ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Second Growth ◽  
Area Growth

A basal area growth model was developed to predict the growth of individual trees in second-growth black spruce (Picea mariana (Mill.) BSP) stands on northeastern Ontario peatlands. The data were derived from stem analysis trees collected in 1985 and 1986 from stands harvested 47-68 years earlier. For a period starting from the date of data collection and going back to 10 years from the harvesting, tree basal area growth, diameters, and stand characteristics were retrospectively calculated at 5-year intervals. To estimate previous mortality, self-thinning relationships for black spruce were applied. In the model, 5-year basal area growth of a tree was expressed as a function of tree diameter, stand-level competition, tree-level competition, and peat thickness. There was considerable change in the growth-size relationship over time. A random parameter approach was applied in model construction to account for the spatial and temporal correlations of the observations. The proposed model explicitly incorporates factors normally included in a "random error" term and, therefore, should provide more sensitive tests of the contributions of the various factors to growth prediction. The estimated model showed only slight bias against the modeling data and the predicted stand basal area development was comparable with that given in other studies.

scholarly journals Cavity Trees, Snags, and Overstory Density in a Riparian Forest in Northeastern Missouri

2011 ◽  
Vol 28 (2) ◽  
pp. 105-109 ◽  
Author(s):  
David Gwaze ◽  
Anthony Elliott
Keyword(s):  
Riparian Forest ◽  
Small Diameter ◽  
Basal Area ◽  
Wildlife Habitat ◽  
Standing Trees ◽  
Bottomland Forests ◽  
Tree Retention ◽  
Current Minimum ◽  
Small Diameter Trees ◽  
Cavity Tree

Abstract Snags and cavity trees are important for wildlife habitat, yet knowledge about their abundance and effects of forest management on these components is lacking for riparian forests. We evaluated the effects of clearcutting with reserves, basal area retention, and no harvest on snags and cavity trees in a riparian forest in northeastern Missouri. We also determined whether the established guidelines for snags and cavity trees in Missouri are being met. Preharvest results indicated that 11.3% of standing trees were snags, and 7% of live standing trees were cavity trees at this site. The proportion of snags was greater in small-diameter trees; however, the proportion of live trees with cavities increased as dbh increased. Preharvest snag density (20.6 trees/ac) and cavity trees (21.2 trees/ac) were well above the current minimum recommendations for wildlife tree retention on bottomland forests in Missouri. Following the harvest and girdling of residual trees >8 in. dbh, the abundance of snags increased, whereas cavity tree densities decreased. If the bottomland hardwood forest is going to contribute habitat of cavity tree-using wildlife, greater attention is needed to retaining cavity trees when harvesting.

Optimizing the Management of Uneven-aged Forest Stands

1974 ◽  
Vol 4 (3) ◽  
pp. 274-287 ◽  
Author(s):  
Darius M. Adams ◽  
Alan R. Ek
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Objective Functions ◽  
Target Structure ◽  
Diameter Class ◽  
Northern Hardwood ◽  
Growing Stock ◽  
Present Worth ◽  
Programming Techniques

Two perennial problems in the management of uneven-aged forests are considered: (i) determination of the optimal sustainable distribution of trees by diameter class, i.e. stand structure, for a given initial stocking level, and (ii) the optimal cutting schedule for the conversion of an irregular stand to a target structure. It is shown, using examples for northern hardwood stands in Wisconsin, that both problems can be solved via mathematical programming techniques. The programming approaches utilize a set of nonlinear equation models for stand table projections which consider the interdependence of size classes within the stand. To illustrate procedures, optimal stand structures are found for a case where initial stand basal area is constrained to specified levels and the objective is to maximize value growth over the cutting cycle. A conversion cutting schedule is then determined for a case in which the objective is maximization of present worth. It is emphasized that both the optimal distribution and conversion problems can be generalized to consider a broad range of objective functions, lengths of cutting cycle, and constraints on the growing stock.

Nonlinear Models for Stand Table Projection in Northern Hardwood Stands

1974 ◽  
Vol 4 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Alan R. Ek
Keyword(s):  
Nonlinear Models ◽  
Basal Area ◽  
Growth Period ◽  
Size Class ◽  
Diameter Class ◽  
Site Class ◽  
Northern Hardwood ◽  
Number Of Stems ◽  
A Site ◽  
Stand Basal Area

Nonlinear equation models were developed for prediction of periodic ingrowth, mortality, and survivor growth by 2-in. (5.1-cm) diameter classes in northern hardwood stands. Equations were constructed using 5 year growth records on 132 plots from stands with a broad range of age and size class distributions. The model for number of ingrowth trees in the smallest diameter class measured was [Formula: see text] where G and N are initial stand basal area and number of trees, respectively, on a per acre basis and the bi's are constants. Mortality in a diameter class expressed as trees per acre was described by the model [Formula: see text] where g and n indicate initial basal area and number of trees in a specified diameter class. Survivor growth was described by prediction of the number of trees in a class which grow into the next larger size class during the growth period. The model for the number of stems moving up was [Formula: see text] where S is a site class term. Considerations in the formulation of the models and a discussion of their utility and limitations are also presented.

scholarly journals Habitat Preferences of the Philippine Tarsier (Tarsius syrichta L.) in Loboc, Bohol, Philippines

2009 ◽  
Vol 9 (1) ◽  
pp. 1-12
Author(s):  
Teofanes Patindol ◽  
Keyword(s):  
Habitat Preference ◽  
Habitat Preferences ◽  
Small Diameter ◽  
Basal Area ◽  
The Philippines ◽  
Strong Wind ◽  
Woody Vines ◽  
Preferred Habitat ◽  
Small Diameter Trees ◽  
Trees And Shrubs

A study was conducted to describle the habitat preference of the Philippines tarsier in Loboc, Bohol. Description of habitat preference was based on species composition and density of the different layers of the stand, mean height, mean diameter and basal area including physical attributes such as aspect, slope and elevation. Three habitat variants of the Philippine tarsier were observed in Loboc, Bohol. The first variant was a relatively open thicket with many small-diameter trees and shrubs and dense undergrowths. The second variant was a thicket of tall grasses, many small diameter trees and dense undergrowths growing under a mahogany plantation. The third variant was a thicket of many small diamater trees and shrubs with less evident woody vines and dense undergrowths with limited exposure to direct sunlight and strong wind being situated along gullies. Preferred habitat of the Phlippine Tarsier are small diameter trees as roosting sites and dense undergrowth as a source of insects and small vertebrates which are preferred food of the animal. The presence of crevices, which are unique to the limestone environment, serve as "hiding places" to protect the animals from predators.

scholarly journals Structural Characteristics of the Tallest Mangrove Forests of the American Continent: A Comparison of Ground-Based, Drone and Radar Measurements

2021 ◽  
Vol 4 ◽  
Author(s):  
Gustavo A. Castellanos-Galindo ◽  
Elisa Casella ◽  
Hector Tavera ◽  
Luis Alonso Zapata Padilla ◽  
Marc Simard
Keyword(s):  
Structural Characteristics ◽  
Regional Climate ◽  
Field Measurements ◽  
Radar Data ◽  
Selective Logging ◽  
Mangrove Forests ◽  
American Continent ◽  
Mangrove Tree ◽  
Surface Models

The Panama Bight eco-region along the Pacific coast of central and South America is considered to have one of the best-preserved mangrove ecosystems in the American continent. The regional climate, with rainfall easily reaching 5–8 m every year and weak wind conditions, contribute to the exceptionally tall mangroves along the southern Colombian and northern Ecuadorian Pacific coasts (Nariño Department and Esmeraldas Province areas). Here we evaluate the use of different methods (ground-based measurements, drone imagery and radar data [Shuttle Radar Topography mission-SRTM and TanDEM-X]) to characterize the structure of the tallest of these forests. In November 2019, three mangrove sites with canopy heights between 50 and 60 m, previously identified with SRTM data, were sampled close to the town of Guapi, Colombia. In addition to in situ field measurements of trees, we conducted airborne drone surveys in order to generate georeferenced orthomosaics and digital surface models (DSMs). We found that the extensive mangrove forests in this area of the Colombian Pacific are almost entirely composed of Rhizophora spp. trees. The tallest mangrove tree measured in the three plots was 57 m. With ca. 900 drone photographs, three orthomosaics (2 cm pixel–1 resolution) and digital surface models (3.5 cm pixel–1) with average area of 4,0 ha were generated. The field-measured canopy heights were used to validate the drone-derived and radar-derived data, confirming these mangrove forests as the tallest in the Americas. The drone-derived orthomosaics showed significant patches of the Golden Leather Fern, Acrostichum aureum, an opportunistic species that can be associated to mangrove degradation, indicating that the mangrove forests investigated here may be threatened from increased selective logging requiring improvements and effective implementation of the current mangrove management plans in Colombia. The techniques used here are highly complementary and may represent the three tiers for carbon reporting, whereby the drone-derived canopy height maps, calibrated with local in situ measurements, provides cheap but reliable Tier 3 estimates of carbon stocks at the project level.

Effect of Thinning on the Production of High-quality Wood in a Quebec Northern Hardwood Stand

1975 ◽  
Vol 5 (1) ◽  
pp. 139-145 ◽  
Author(s):  
M. R. Roberge
Keyword(s):  
Sugar Maple ◽  
Basal Area ◽  
Yellow Birch ◽  
Diameter Class ◽  
High Quality ◽  
Thinning Intensity ◽  
Northern Hardwood ◽  
Birch Trees ◽  
Stem Quality ◽  
Fire Origin

In 1963, two intensities of thinning were carried out in a 60-year-old northern hardwood stand of fire origin. Yellow birch (Betulaalleghaniensis Britt.) made up as much as 40% of the total number of trees 9 cm d.b.h. and up. By 1973, both sugar maple (Acersaccharum Marsh.) and yellow birch had responded to thinning, the former more than the latter. The percentages of yellow birch trees had not changed regardless of treatment. There were between 120 and 129 trees/ha of the 25–39 cm diameter class in the unthinned as well as in the thinned areas. Basal area of the trees 9 cm d.b.h. and up had increased by 5.4, 7.6, and 8.1 m2/ha in the unthinned, 20% thinned, and 40% thinned area, respectively. A decrease in stem quality was not observed, even at the 40% thinning intensity. Both thinning intensities were thus successful except that they somewhat favored sugar maple at the expense of yellow birch.

scholarly journals Ecological and Structural Characteristics of Riparian Forest in Omo Biosphere Reserve

2020 ◽  
Vol 24 (9) ◽  
pp. 1687-1691
Author(s):  
O.R. Olatidoye ◽  
O.J. Oyelowo ◽  
O.D. Akinyemi ◽  
C. Kambai ◽  
A.A. Ayodele
Keyword(s):  
Riparian Forest ◽  
Structural Characteristics ◽  
Biosphere Reserve ◽  
Basal Area ◽  
Riparian Forests ◽  
Diameter Class ◽  
Species Dominance ◽  
The Core ◽  
Class Distribution ◽  
Major River

An investigation on the structural characteristics of the riparian forest in Omo Biosphere Reserve was carried out. The structure was analyzed  through diameter class distribution, basal area and breast height. Riparian forest showed a major characteristic in the physiognomy of forests along major river, streams and Upland vegetation and the Core, Buffer and Transition zones that is highly variable in the diameter class distribution  (reserve J type), Mean basal area per hectare for major river is 294,089.30 cm2/ ha, Stream 613.027 cm2/ha, and Upland 205,648 cm3/ha. Mean basal area for core is 507,399.50 cm2/ha, buffer had 340,699 cm2/ha and transition 264,656 cm2/ha. While mean volume per hectare for core is 7955.2 m3/ha, buffer 7260 m3/ha and Transition 6254.4 m3/ha. Maximum dbh of 246 cm was obtained in the core species. Many stands of riparian forests are facing various levels of structural and floristic simplification, which include fundamental transformations in vegetation physiognomy from dense stands to riparian scrub or bare land. Keyword: Riparian forests, structure, diameter, basal area, species dominance, Omo

scholarly journals A large database supports the use of simple models of post-fire tree mortality for thick-barked conifers, with less support for other species

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
C. Alina Cansler ◽  
Sharon M. Hood ◽  
Phillip J. van Mantgem ◽  
J. Morgan Varner
Keyword(s):  
Tree Mortality ◽  
Characteristic Curve ◽  
Small Diameter ◽  
Fire Effects ◽  
Tree Level ◽  
Clear Understanding ◽  
Bark Thickness ◽  
Mortality Models ◽  
Species Specific ◽  
Stem Mortality

Abstract Background Predictive models of post-fire tree and stem mortality are vital for management planning and understanding fire effects. Post-fire tree and stem mortality have been traditionally modeled as a simple empirical function of tree defenses (e.g., bark thickness) and fire injury (e.g., crown scorch). We used the Fire and Tree Mortality database (FTM)—which includes observations of tree mortality in obligate seeders and stem mortality in basal resprouting species from across the USA—to evaluate the accuracy of post-fire mortality models used in the First Order Fire Effects Model (FOFEM) software system. The basic model in FOFEM, the Ryan and Amman (R-A) model, uses bark thickness and percentage of crown volume scorched to predict post-fire mortality and can be applied to any species for which bark thickness can be calculated (184 species-level coefficients are included in the program). FOFEM (v6.7) also includes 38 species-specific tree mortality models (26 for gymnosperms, 12 for angiosperms), with unique predictors and coefficients. We assessed accuracy of the R-A model for 44 tree species and accuracy of 24 species-specific models for 13 species, using data from 93 438 tree-level observations and 351 fires that occurred from 1981 to 2016. Results For each model, we calculated performance statistics and provided an assessment of the representativeness of the evaluation data. We identified probability thresholds for which the model performed best, and the best thresholds with either ≥80% sensitivity or specificity. Of the 68 models evaluated, 43 had Area Under the Receiver Operating Characteristic Curve (AUC) values ≥0.80, indicating excellent performance, and 14 had AUCs <0.7, indicating poor performance. The R-A model often over-predicted mortality for angiosperms; 5 of 11 angiosperms had AUCs <0.7. For conifers, R-A over-predicted mortality for thin-barked species and for small diameter trees. The species-specific models had significantly higher AUCs than the R-A models for 10 of the 22 models, and five additional species-specific models had more balanced errors than R-A models, even though their AUCs were not significantly different or were significantly lower. Conclusions Approximately 75% of models tested had acceptable, excellent, or outstanding predictive ability. The models that performed poorly were primarily models predicting stem mortality of angiosperms or tree mortality of thin-barked conifers. This suggests that different approaches—such as different model forms, better estimates of bark thickness, and additional predictors—may be warranted for these taxa. Future data collection and research should target the geographical and taxonomic data gaps and poorly performing models identified in this study. Our evaluation of post-fire tree mortality models is the most comprehensive effort to date and allows users to have a clear understanding of the expected accuracy in predicting tree death from fire for 44 species.

Koalas continue to occupy their previous home-ranges after selective logging in Callitris - Eucalyptus forest

2007 ◽  
Vol 34 (2) ◽  
pp. 94 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Matthew A. Stanton ◽  
Traecey E. Brassil
Keyword(s):  
Home Range ◽  
Basal Area ◽  
Selective Logging ◽  
Home Ranges ◽  
Phascolarctos Cinereus ◽  
Eucalyptus Forest ◽  
South Wales ◽  
Callitris Glaucophylla ◽  
One Year ◽  
Cypress Pine

The koala (Phascolarctos cinereus) is a charismatic, high-profile species whose conservation needs are commonly perceived to be incompatible with logging. However, koala biology and the results of chronosequence studies elsewhere suggest that this species may tolerate a degree of habitat alteration caused by logging. In this study, 30 koalas, five in each of six areas available for logging within a mixed white cypress pine (Callitris glaucophylla)–Eucalyptus forest in north-western New South Wales, were radio-tracked for one year during 1997–1998 to determine their movements, home-range sizes and tree preferences. Five months after the study began, three of these areas were logged selectively for sawlogs and thinnings of the white cypress pine, a tree that is important to koalas for daytime shelter. This removed about one-quarter of the stand basal area, but the eucalypt component was unaffected. The remaining three areas were left undisturbed as controls. Radio-tracking continued in all six areas for another seven months. Koalas continued to occupy all or part of their previous home-ranges after selective logging, and home-range sizes remained similar between logged and unlogged areas. Home-ranges for both sexes overlapped and were ~12 ha for males and 9 ha for females. Koala survival and the proportions of breeding females were similar in logged and unlogged areas. The principal food trees of the koala were red gums, mainly Eucalyptus blakelyi and E. chloroclada, and the pilliga box (E. pilligaensis), none of which were logged in this study. These results suggest that selective logging for white cypress pine does not appear to adversely affect koala populations and that koalas may not be as sensitive to logging as previously thought. Further work is required to determine thresholds in the level of retention of koala food trees in logging operations.

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