Abundance and distribution of cavity trees in an old-growth subtropical montane evergreen broad-leaved forest

We examined the relationship between the density of cavity trees and forest structure characteristics and explored the occurrence of cavity trees among different tree species and diameter breast height (DBH) size in a subtropical evergreen broad-leaved forest in the Ailao Mountains in southwestern China. Cavity trees accounted for 7.9% of living trees and 16.3% of dead trees. Average density of living cavity trees (86.3 trees·ha–1) was 6.9 times that of dead cavity trees. Density of living cavity trees was positively correlated with the density of living trees. Cavity trees showed a skewed distribution among DBH classes that peaked at DBHs of 20–40 cm. Moreover, the probability that a living tree was cavity-bearing was logistically related to DBH. Overall, the likelihood of trees being cavity-bearing differed significantly among species. The proportions of cavity trees among the 23 species having more than 63 trees were positively related to the average DBH and to the largest DBH recorded for each species. We suggest that (1) living tree density is important in determining density of cavity trees and (2) differences in proportion of living cavity trees among species is caused mostly by differences in average DBH of each species.

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Ethanol in ponderosa pine as an indicator of physiological injury from fire and its relationship to secondary beetles

Canadian Journal of Forest Research ◽

10.1139/x03-007 ◽

2003 ◽

Vol 33 (5) ◽

pp. 870-884 ◽

Cited By ~ 63

Author(s):

Rick G Kelsey ◽

Gladwin Joseph

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Xylem Sap ◽

Upward Movement ◽

Stem Base ◽

Breast Height ◽

Dead Trees ◽

Crown Scorch ◽

Second Year ◽

The Relationship

Sixteen days after a September wildfire, ethanol and water were measured in phloem and sapwood at breast height and the base of Pinus ponderosa Dougl. ex P. & C. Laws. with zero (control), moderate, heavy, and severe crown scorch. The quantity of ethanol increased with each level of injury, resulting in trees with severe scorch containing 15 and 53 times more phloem and sapwood ethanol, respectively, than controls. Ethanol concentrations in the sapwood and adjacent phloem were related, probably as a result of diffusion. Upward movement in xylem sap was most likely responsible for the relationship between sapwood ethanol concentrations at breast height and the stem base. As trees recovered from their heat injuries, the ethanol concentrations declined. In contrast, ethanol accumulated in dead trees that lost their entire crowns in the fire. Various bark and xylophagous beetles landed in greater numbers on fire-damaged trees than on controls the following spring and summer, suggesting that ethanol was being released to the atmosphere and influencing beetle behavior. Beetle landing was more strongly related to sapwood ethanol concentrations the previous September than in May. Sapwood ethanol measured 16 days after the fire was the best predictor of second-year mortality for trees with heavy and severe crown scorch.

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The characteristics of squirrel glider (Petaurus norfolcensis) den trees in subtropical Australia

Australian Journal of Zoology ◽

10.1071/zo08053 ◽

2008 ◽

Vol 56 (1) ◽

pp. 13 ◽

Cited By ~ 25

Author(s):

Georgia L. Beyer ◽

Ross L. Goldingay ◽

David J. Sharpe

Keyword(s):

New South ◽

Effective Management ◽

Living Tree ◽

Breast Height ◽

North East ◽

South Wales ◽

Dead Trees ◽

Squirrel Glider ◽

Tree Hollow ◽

Subtropical Australia

Effective management of tree-hollow-dependent wildlife requires a sound knowledge of the characteristics of the trees used for shelter or breeding. We used radio-tracking to identify the den trees of squirrel gliders (Petaurus norfolcensis) in south-east Queensland (Qld) and north-east New South Wales (NSW). Squirrel gliders used dead trees as well as 13 species of living tree for dens across the two locations. Dead trees accounted for a large percentage of dens (54% of 48 dens in Qld, and 50% of 18 dens in NSW) despite comprising only 3–10% of the forest (trees >20 cm diameter at breast height (dbh)) at each location. This preference is largely due to dead trees being more likely to contain hollows, accounting for 26–44% of available hollow-bearing trees. Mean den tree size (dbh) was 48.9 ± 2.4 cm in Qld and 62.8 ± 5.6 cm in NSW. Den entrance height averaged 6.8 ± 1.2 m in Qld and 11.9 ± 1.3 m in NSW. Fissures in the trunk and holes in branches were the most common of six hollow types used. At one location branch end hollows were ignored relative to their availability. Den entrances varied in size (2.5–12 cm wide) but most were ≤5 cm in diameter. Entrance size of hollows appears to be the hollow attribute of most importance to squirrel gliders. Monitoring of these den trees over several years revealed the collapse of three dead den trees at each location, which is equivalent to an annual loss of 3% of den trees. Further research is needed to determine whether this will lead to a future shortage of den trees.

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Effect of minimum diameter at breast height and standing dead wood field measurements on the accuracy of ALS-based forest inventory

Canadian Journal of Forest Research ◽

10.1139/cjfr-2015-0103 ◽

2015 ◽

Vol 45 (10) ◽

pp. 1280-1288 ◽

Cited By ~ 4

Author(s):

Juha Keränen ◽

Jussi Peuhkurinen ◽

Petteri Packalen ◽

Matti Maltamo

Keyword(s):

Forest Inventory ◽

Laser Scanning ◽

Dead Wood ◽

Minimum Diameter ◽

Living Tree ◽

Breast Height ◽

Dead Trees ◽

Standing Dead ◽

Standing Dead Trees ◽

Young Forests

Where airborne laser scanning (ALS) measures the entire aboveground vegetation, the target of a stand-level forest inventory is usually the living tree stock above a given diameter but excluding standing dead trees. The aim here was to investigate the effects of varying field-measured minimum diameters (3–10 cm) and standing dead wood on ALS-based forest inventories. The characteristics considered in this case were volume, basal area, number of stems, mean diameter, and mean height for each species, as well as the total growing stock and the total aboveground biomass. The field data comprised measurements of all trees that were ≥3 cm at breast height (1.3 m) on 601 sample plots located in pine-dominated managed forests in eastern Finland. The results showed that the minimum diameter had a significant effect on the estimates obtained in young forests, for which the three smallest minimum diameter datasets (3, 4, and 5 cm) gave the most accurate estimates. Minimum diameter had no marked influence in the case of middle-aged or mature forests. The inclusion of standing dead trees did not have any effect on the estimates of living tree characteristics. The effect of minimum diameter is minor where large-area inventory applications are concerned; however, especially from a silvicultural point of a view, a minimum diameter of 3 cm should be employed in young forests, for which a large proportion of the tree stock usually consists of small trees, i.e., with diameters of <5 cm.

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Influence of strata-specific forest structural features on the regeneration of the evergreen broad-leaved forest in Tianmu Mountain

PLoS ONE ◽

10.1371/journal.pone.0247339 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0247339

Author(s):

Junsong Long ◽

Mengping Tang ◽

Guangsheng Chen

Keyword(s):

Species Richness ◽

Tree Species ◽

Structural Characteristics ◽

Diameter At Breast Height ◽

Breast Height ◽

Crown Width ◽

Broad Leaved Forest ◽

Forest Strata ◽

Richness Index ◽

Leaved Forest

The vertical stratification of the stand may lead to a high heterogeneity of microenvironment in the forest, which further influences the understory regeneration and succession of the forest. Most relevant previous studies emphasized the overall effects of the Whole-stand structural characteristics on understory regeneration, while the strata-specific impacts of the overstory should be explored especially for those forests with a complicated combination of overstory species and heights. In this study, a subtropical evergreen broad-leaved forest in Tianmu Mountain of China was intensively investigated within 25 plots of 20 m × 20 m, aiming to find out how significant the stratified overstory (trees with diameter at breast height (DBH) ≥ 5 cm) structure and non-structure characteristics impact the understory (trees with DBH < 5 cm) regeneration. Regardless of species composition, the studied overstory was evenly divided into three strata (i.e. upper, middle and lower strata) according to their heights. Redundancy analysis was applied to explore both overall and strata-specific forest structure on characteristics (height, DBH, species diversity, and density) of tree regeneration. We found that the overall effect of the whole overstory on the forest regeneration depended mostly on diameter at breast height (DBH), tree species richness index and crown width. However, when analyzing with the strata-specific characteristics, the most pronounced impact factors for the regeneration were tree height of the upper and lower forest strata, tree species richness index and crown width of the middle and lower forest strata, and the competition index impact of the lower forest stratum. Among the three strata, the lower forest stratum showed the most significant impact with three characteristics on the understory regeneration, which may be attributed to their direct competition within the overlapping near-ground niches. Among the new generations, seedlings and saplings were more sensitive to the overstory structural characteristics than young trees. Our results suggest that the overstory showed strata-specific effects on the understory regeneration of evergreen broad-leaved forests in subtropical China, which provides theoretical basis for strata-specific forest management in similar forests.

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Classification of vegetation in Cucphuong National Park with the aim of large-scale mapping, Vietnam

Geobotanical mapping ◽

10.31111/geobotmap/1994-1995.64 ◽

1996 ◽

pp. 64-67 ◽

Cited By ~ 1

Author(s):

Nguen Nghia Thin ◽

Nguen Ba Thu ◽

Tran Van Thuy

Keyword(s):

National Park ◽

Large Scale ◽

Satellite Images ◽

Field Work ◽

Aerial Photographs ◽

Vegetation Map ◽

Dense Forest ◽

Broad Leaved Forest ◽

Leaved Forest

The tropical seasonal rainy evergreen broad-leaved forest vegetation of the Cucphoung National Park has been classified and the distribution of plant communities has been shown on the map using the relations of vegetation to geology, geomorphology and pedology. The method of vegetation mapping includes: 1) the identifying of vegetation types in the remote-sensed materials (aerial photographs and satellite images); 2) field work to compile the interpretation keys and to characterize all the communities of a study area; 3) compilation of the final vegetation map using the combined information. In the classification presented a number of different level vegetation units have been identified: formation classes (3), formation sub-classes (3), formation groups (3), formations (4), subformations (10) and communities (19). Communities have been taken as mapping units. So in the vegetation map of the National Park 19 vegetation categories has been shown altogether, among them 13 are natural primary communities, and 6 are the secondary, anthropogenic ones. The secondary succession goes through 3 main stages: grassland herbaceous xerophytic vegetation, xerophytic scrub, dense forest.

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