Gradual and sudden forest canopy gaps in Allegheny northern hardwood forests

To determine the importance of gradual tree death to gap dynamics in Allegheny northern hardwood forests, line transect surveys of gaps and gap makers were conducted in three mature forests in central New York. Of the total number of gaps, 71.7% were classified as gradual gaps, meaning they were partial openings in the canopy caused by either trees with greater than 50% branch loss or standing dead trees. Sudden gaps, caused by trees that had fallen, constituted 9.7% of the total number of gaps. Another 18.6% of the gaps had mixed causes. American beech (Fagusgrandifolia Ehrh.), which is subject to beech bark disease in the study area, was the predominant gap maker, representing 52.4% of the gap makers compared with 25.6% of the canopy trees. It is suggested that future studies of forest gap dynamics include measures of gaps forming over a period of time, particularly in forests subject to decline and biotic diseases and in other forests where gradual tree death and standing dead trees are known to be important.

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Forest age and management effects on epiphytic bryophyte communities in Adirondack northern hardwood forests, New York, U.S.A.

Canadian Journal of Forest Research ◽

10.1139/x02-083 ◽

2002 ◽

Vol 32 (9) ◽

pp. 1562-1576 ◽

Cited By ~ 54

Author(s):

Gregory G McGee ◽

Robin W Kimmerer

Keyword(s):

New York ◽

Community Composition ◽

Tree Species ◽

Large Diameter ◽

Hardwood Forests ◽

Host Tree ◽

Old Growth ◽

Northern Hardwood Forests ◽

Northern Hardwood ◽

Host Tree Species

The objective of this study was to assess the influence of substrate heterogeneity on epiphytic bryophyte communities in northern hardwood forests of varying disturbance histories. Specifically, we compared bryophyte abundance (m2·ha1) and community composition among partially cut; maturing, 90- to 100-year-old, even-aged; and old-growth northern hardwood stands in Adirondack Park, New York, U.S.A. Total bryophyte cover from 0 to 1.5 m above ground level on trees [Formula: see text]10 cm diameter at breast height (DBH) did not differ among the three stand types. However, bryophyte community composition differed among host tree species and among stand types. Communities in partially cut and maturing stands were dominated by xerophytic bryophytes (Platygyrium repens, Frullania eboracensis, Hypnum pallescens, Brachythecium reflexum, Ulota crispa), while old-growth stands contained a greater representation of calcicoles and mesophytic species (Brachythecium oxycladon, Anomodon rugelii, Porella platyphylloidea, Anomodon attenuatus, Leucodon brachypus, Neckera pennata). This mesophyte-calcicole assemblage occurred in all stand types but was limited by the abundance of large-diameter (>50 cm DBH), thick-barked, hardwood host trees (Acer saccharum Marsh., Tilia americana L., Fraxinus americana L.). This study suggested that epiphytic bryophyte diversity can be sustained and enhanced in managed northern hardwood forests by maintaining host tree species diversity and retaining large or old, thick-barked residual hardwood stems when applying even-aged and uneven-aged silviculture systems.

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Interference to Hardwood Regeneration in Northeastern North America: Assessing and Countering Ferns in Northern Hardwood Forests

Northern Journal of Applied Forestry ◽

10.1093/njaf/23.3.166 ◽

2006 ◽

Vol 23 (3) ◽

pp. 166-175 ◽

Cited By ~ 13

Author(s):

Heather M. Engelman ◽

Ralph D. Nyland

Keyword(s):

New York ◽

Hardwood Forests ◽

Tree Seedlings ◽

Control Methods ◽

Northern Hardwood Forests ◽

Northeastern North America ◽

Northern Hardwood ◽

Light Levels ◽

Survival And Development ◽

Further Development

Abstract The extremely dense shade cast by spreading ferns, particularly hayscented, New York, and bracken ferns, interferes with the survival and development of tree seedlings in northern hardwood forests. Excessive bracken frond litter and hayscented fern root mats can also prevent adequate germination and seedling development. In addition, the herbaceous cover may harbor detrimental small herbivores, while large ones often preferentially browse seedlings that grow through this layer. Increased understory light levels after an overstory disturbance, abundant soil moisture, fire, and herbivory promote ferns, whereas excessive and repeated cold or drought deter fern development and propagation. The most promising control methods repress ferns until seedlings cast adequate shade to inhibit further development of the fern layer. When ferns cover more than 30% of the understory, well-timed applications of either glyphosate or sulfometuron methyl have successfully controlled hayscented, New York, and bracken ferns. Two carefully timed mowings annually for at least 2 years have also provided long-lasting control on level, accessible sites. Deer populations must be reduced where browsing prevents development of desirable plants.

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Changes in faunal and vegetation communities along a soil calcium gradient in northern hardwood forests

Canadian Journal of Forest Research ◽

10.1139/x2012-071 ◽

2012 ◽

Vol 42 (6) ◽

pp. 1141-1152 ◽

Cited By ~ 21

Author(s):

Colin M. Beier ◽

Anne M. Woods ◽

Kenneth P. Hotopp ◽

James P. Gibbs ◽

Myron J. Mitchell ◽

...

Keyword(s):

New York ◽

Acidic Deposition ◽

Basal Area ◽

Hardwood Forests ◽

Trophic Levels ◽

Community Diversity ◽

Northern Hardwood Forests ◽

Northern Hardwood ◽

Underlying Mechanisms ◽

Increasing Trends

Depletion of Ca from forest soils due to acidic deposition has had potentially pervasive effects on forest communities, but these impacts remain largely unknown. Because snails, salamanders, and plants play essential roles in the Ca cycle of northern hardwood forests, we hypothesized that their community diversity, abundance, and structure would vary with differences in biotic Ca availability. To test this hypothesis, we sampled 12 upland hardwood forests representing a soil Ca gradient in the Adirondack Mountains, New York (USA), where chronic deposition has resulted in acidified soils but where areas of well-buffered soils remain Ca rich due to parent materials. Along the gradient of increasing soil [Ca2+], we observed increasing trends in snail community richness and abundance, live biomass of redback salamanders ( Plethodon cinereus (Green, 1818)), and canopy tree basal area. Salamander communities were dominated by mountain dusky salamanders ( Desmognathus ochrophaeus Cope, 1859) at Ca-poor sites and changed continuously along the Ca gradient to become dominated by redback salamanders at the Ca-rich sites. Several known calciphilic species of snails and plants were found only at the highest-Ca sites. Our results indicated that Ca availability, which is shaped by geology and acidic deposition inputs, influences northern hardwood forest ecosystems at multiple trophic levels, although the underlying mechanisms require further study.

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Gap dynamics in Allegheny northern hardwood forests in the presence of beech bark disease and gypsy moth disturbances

Forest Ecology and Management ◽

10.1016/s0378-1127(00)00391-1 ◽

2001 ◽

Vol 144 (1-3) ◽

pp. 265-274 ◽

Cited By ~ 19

Author(s):

Marianne E Krasny ◽

Lina M DiGregorio

Keyword(s):

Gypsy Moth ◽

Hardwood Forests ◽

Gap Dynamics ◽

Beech Bark Disease ◽

Northern Hardwood Forests ◽

Northern Hardwood

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Occurrence of termites (Isoptera) on living and standing dead trees in a tropical dry forest in Mexico

PeerJ ◽

10.7717/peerj.4731 ◽

2018 ◽

Vol 6 ◽

pp. e4731 ◽

Cited By ~ 4

Author(s):

Nancy Calderón-Cortés ◽

Luis H. Escalera-Vázquez ◽

Ken Oyama

Keyword(s):

Forest Canopy ◽

Dead Wood ◽

Tropical Dry Forest ◽

Dry Forest ◽

Dead Tree ◽

Ecological Processes ◽

Dead Trees ◽

Standing Dead ◽

Standing Dead Trees ◽

Main Factor

Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60–98% of standing dead trees and 23–59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057–0.066 trees/m2) than in riparian forests (0.022 and 0.027 trees/m2), even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01–0.09 trees/m2) than in larger class sizes (0–0.02 trees/m2). Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil.

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Strong temporal variation in treefall and branchfall rates in a tropical forest is explained by rainfall: results from five years of monthly drone data for a 50-ha plot

10.5194/bg-2021-102 ◽

2021 ◽

Author(s):

Raquel Fernandes Araujo ◽

Samuel Grubinger ◽

Carlos Henrique Souza Celes ◽

Robinson I. Negrón-Juárez ◽

Milton Garcia ◽

...

Keyword(s):

Tropical Forest ◽

Temporal Variation ◽

Forest Canopy ◽

Barro Colorado Island ◽

Weibull Function ◽

Wet Season ◽

Canopy Disturbance ◽

Dead Trees ◽

Standing Dead ◽

Standing Dead Trees

Abstract. A mechanistic understanding of how tropical tree mortality responds to climate variation is urgently needed to predict how tropical forest carbon pools will respond to anthropogenic global change, which is altering the frequency and intensity of storms, droughts, and other climate extremes in tropical forests. We used five years of approximately monthly drone-acquired RGB imagery for 50 ha of mature tropical forest on Barro Colorado Island, Panama, to quantify spatial structure, temporal variation, and climate correlates of canopy disturbances, i.e., sudden and major drops in canopy height due to treefalls, branchfalls, or collapse of standing dead trees. Treefalls accounted for 77 % of the total area and 60 % of the total number of canopy disturbances in treefalls and branchfalls combined. The size distribution of canopy disturbances was close to a power function for sizes above 25 m2, and best fit by a Weibull function overall. Canopy disturbance rates varied strongly over time and were higher in the wet season, even though windspeeds were lower in the wet season. The strongest correlate of temporal variation in canopy disturbance rates was the frequency of 1-hour rainfall events above the 99.4th percentile (here 35.7 mm hour−1, r = 0.67). We hypothesize that extreme high rainfall is associated with both saturated soils, increasing risk of uprooting, and with gusts having high horizontal and vertical windspeeds that increase stresses on tree crowns. These results demonstrate the utility of repeat drone-acquired data for quantifying forest canopy disturbance rates over large spatial scales at fine temporal and spatial resolution, thereby enabling strong tests of linkages to drivers. Future studies should include high frequency measurements of vertical and horizontal windspeeds and soil moisture to better capture proximate drivers, and incorporate additional image analyses to quantify standing dead trees in addition to treefalls.

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A crown model for simulating long-term stand and gap dynamics in northern hardwood forests

Forest Ecology and Management ◽

10.1016/s0378-1127(00)00606-x ◽

2001 ◽

Vol 152 (1-3) ◽

pp. 235-258 ◽

Cited By ~ 25

Author(s):

Jungkee Choi ◽

Craig G Lorimer ◽

Jayne Vanderwerker ◽

William G Cole ◽

George L Martin

Keyword(s):

Hardwood Forests ◽

Gap Dynamics ◽

Northern Hardwood Forests ◽

Northern Hardwood

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Classification of Tree Species as Well as Standing Dead Trees Using Triple Wavelength ALS in a Temperate Forest

Remote Sensing ◽

10.3390/rs11222614 ◽

2019 ◽

Vol 11 (22) ◽

pp. 2614 ◽

Cited By ~ 3

Author(s):

Nina Amiri ◽

Peter Krzystek ◽

Marco Heurich ◽

Andrew Skidmore

Keyword(s):

Tree Species ◽

Feature Selection Method ◽

Silver Fir ◽

Maximum Point ◽

Individual Tree ◽

Dead Trees ◽

Multi Wavelength ◽

Standing Dead ◽

Standing Dead Trees ◽

532 Nm

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.

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Preferences for Northern Hardwood Silviculture among Family Forest Owners in Michigan’s Upper Peninsula

Journal of Forestry ◽

10.1093/jofore/fvaa051 ◽

2020 ◽

Author(s):

Alexander C Helman ◽

Matthew C Kelly ◽

Mark D Rouleau ◽

Yvette L Dickinson

Keyword(s):

Species Diversity ◽

Hardwood Forests ◽

Family Forest Owners ◽

Forest Owners ◽

Upper Peninsula ◽

Northern Hardwood Forests ◽

Family Forest ◽

Northern Hardwood ◽

Single Tree ◽

Single Tree Selection

Abstract Managing northern hardwood forests using high-frequency, low-intensity regimes, such as single-tree selection, favors shade-tolerant species and can reduce tree species diversity. Management decisions among family forest owners (FFO) can collectively affect species and structural diversity within northern hardwood forests at regional scales. We surveyed FFOs in the Western Upper Peninsula of Michigan to understand likely future use of three silvicultural treatments—single-tree selection, shelterwood, and clearcut. Our results indicate that FFOs were most likely to implement single-tree selection and least likely to implement clearcut within the next 10 years. According to logistic regression, prior use of a treatment and perceived financial benefits significantly increased the odds for likely use for all three treatments. Having received professional forestry assistance increased likely use of single-tree selection but decreased likely use of shelterwood. We discuss these results within the context of species diversity among northern hardwood forests throughout the region.

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