Nonlinear Models for Stand Table Projection in Northern Hardwood Stands

1974 ◽  
Vol 4 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Alan R. Ek

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.

1992 ◽  
Vol 22 (9) ◽  
pp. 1235-1248 ◽  
Author(s):  
Jerome K. Vanclay

A two-stage model predicts the recruitment (i.e., the number of stems reaching or exceeding 10 cm DBH) of the 100 species that account for 97% of all the recruitment observed on 217 permanent sample plots in the tropical rain forest of north Queensland. The first stage predicts the probability of the occurrence of any recruitment from stand basal area and the presence of that species in the existing stand. These probabilities can be implemented stochastically, or deterministically by summing the probabilities and initiating recruitment on unity. The second stage indicates the expected amount of recruitment, given that it is known to occur, and employs stand basal area, the relative number of trees of that species in the stand, and site quality. This approach is easily implemented in growth models and planning systems.


2008 ◽  
Vol 25 (3) ◽  
pp. 133-138 ◽  
Author(s):  
Julia I. Burton ◽  
Eric K. Zenner ◽  
Lee E. Frelich

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.


1991 ◽  
Vol 67 (4) ◽  
pp. 389-392
Author(s):  
Yvon Grenier ◽  
France Lapointe

This paper presents six tree factor tables, for basal area factors of 2, 3 and 4 m2/ha and diameter classes of 2 and 10 cm. They can be used for point sampling inventories of unevenaged stands while the purpose is to estimate the number of stems by diameter class. We used a method based on the fact that diameters in a diameter class do not have equal weights. One can calculate tree factor in a more precise manner that what could have been done with traditional method. Key words: diameter class, tree factor, unevenaged structure.


1974 ◽  
Vol 4 (3) ◽  
pp. 274-287 ◽  
Author(s):  
Darius M. Adams ◽  
Alan R. Ek

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.


2005 ◽  
Vol 32 (1) ◽  
pp. 23 ◽  
Author(s):  
Teresa J. Eyre ◽  
Ross L. Goldingay

An extensive survey was conducted to locate sap trees used by the yellow-bellied glider (Petaurus australis) throughout the forests and woodlands of southern Queensland, across an area of 43.7 million hectares. We recorded the characteristics of 478 sap trees located at 109 of 297 sites surveyed. Only 13 tree species were selected by gliders for sap feeding throughout the study region, with the grey gum species Eucalyptus longirostrata and E. biturbinata most likely to be incised for sap. Of the tree species used for sap feeding by gliders, trees >40 cm in diameter at breast height (dbh) were used more than would be expected on the basis of their abundance in the forest. The number of sap trees with active and recently active feed scars at a site ranged from 0 to 12. Factors that appear to influence the abundance of active and recently active sap trees at a site include intensity of disturbance (basal area of cut stumps and dead trees), the number of stems in the 41–60 and 61–80 cm dbh classes, and number of Myrtaceae species. The response to these variables could be indicative of habitat quality, and the availability of alternative foraging substrates such as flower cover and decorticating bark. Intensification of selective logging in south-east Queensland, as an outcome of the Southeast Queensland Regional Forest Agreement, could potentially marginalise glider habitat. This would necessitate the retention of potential, or ‘recruit’, sap trees to maintain yellow-bellied glider habitat in these areas.


1994 ◽  
Vol 24 (2) ◽  
pp. 350-357 ◽  
Author(s):  
M.T. Nichols ◽  
R.C . Lemin Jr. ◽  
W.D. Ostrofsky

Residual stand damage was evaluated following partial cutting with a mechanical and a conventional harvesting system in a northern hardwood stand in Maine. Damage from harvesting using a swing to bunch feller–buncher and grapple skidder was compared with damage from a chainsaw and cable skidder operation. Harvesting resulted in actual residual basal areas of 10 and 16.5 m2/ha in a heavy and light conventional treatment, respectively, and in 9 and 6.9 m2/ha in two mechanized treatments. The proportion of stems wounded averaged 22–44% in the conventional, and 20–31% in the mechanized operation. Wounds were significantly (p < 0.05) longer in the heavy conventional [Formula: see text] treatment than in light conventional [Formula: see text] and mechanized ([Formula: see text] and 60.2 cm) treatments. Wounds were located higher on the stems in the 9 m/ha mechanized [Formula: see text] than in the 10 m2/ha conventional treatment [Formula: see text]. A separate survey of the mechanized harvest showed that season of harvest (winter vs. summer) significantly affected wound location and the wound width to tree circumference ratio. A model was developed that relates harvesting treatment (light and heavy conventional and two heavy mechanical), species, distance of a stem from the edge a skid trail or access corridor, and initial stand basal area to the probability of injuring an individual stem. Mechanized harvesting using equipment with long-reach swing to bunch felling capability appears to be better than some other mechanical systems, and no worse than conventional harvesting systems, but the need to further reduce damage levels is evident.


1975 ◽  
Vol 5 (1) ◽  
pp. 139-145 ◽  
Author(s):  
M. R. Roberge

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.


Ecosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. e02462 ◽  
Author(s):  
Micah Wright ◽  
Rosemary L. Sherriff ◽  
Amy E. Miller ◽  
Tammy Wilson

2021 ◽  
Author(s):  
Mathias Neumann ◽  
Hubert Hasenauer

Abstract Competition for resources (light, water, nutrients, etc.) limits the size and abundance of alive trees a site can support. This carrying capacity determines the potential carbon sequestration in alive trees as well as the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as case study. We expected lower increment for heavy thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, whereas two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. The heavy thinned stand had over ten years similar increment as the moderate thinned and unthinned stands. Basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands lead to much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.


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