Successional replacement of old-growth white oak by mixed mesophytic hardwoods in southwestern Pennsylvania

1990 ◽  
Vol 20 (12) ◽  
pp. 1864-1870 ◽  
Author(s):  
Marc D. Abrams ◽  
Julie A. Downs
Keyword(s):  
Radial Growth ◽  
Forest Type ◽  
Growth Patterns ◽  
White Oak ◽  
Importance Value ◽  
Old Growth ◽  
Canopy Position ◽  
Mesic Site ◽  
Southwestern Pennsylvania ◽  
Understory Trees

Presettlement forests in southwestern Pennsylvania were dominated by Quercusalba L. A relatively undisturbed remnant of this forest type on a mesic site was surveyed to investigate the successional status of Q. alba in the region. This old-growth stand is now dominated by Fagusgrandifolia Ehrh., Acerrubrum L., and Liriodendrontulipifera L., representing 62% of the importance value total. Oaks (Q. alba, Q. rubra L., and Q. velutina Lam.) totalled only 18% of the importance value total. The overstory mainly comprised L. tulipifera, F. grandifolia, Q. alba, and Nyssasylvatica Marsh. Acerrubrum and Prunusserotina Ehrh. were the most abundant seedlings, and few saplings of any species were present. The oldest and largest trees were oak, with two Q. alba >300 years. Over 90% of all trees were <120 years old, including many F. grandifolia, L. tulipifera, A. rubrum, and A. saccharum Marsh., but few oaks. Logging of several trees in the 1930–1940s apparently accelerated the speed of obtaining dominance for these mixed mesophytic species. Radial growth patterns varied with species and canopy position. On average, the oldest oaks exhibited slow radial growth of <0.75 mm/year. Many understory trees had average radial growth of >1.5–2.0 mm/year and exhibited a release in growth associated with logging in the 1930–1940s. We believe this forest represents a primary example of an advanced stage of oak replacement by mixed mesophytic species, a process that seems inevitable in many eastern forests.

scholarly journals Unveiling the Diversity of Tree Growth Patterns in Boreal Old-Growth Forests Reveals the Richness of Their Dynamics

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 252 ◽  
Author(s):  
Maxence Martin ◽  
Cornélia Krause ◽  
Nicole J. Fenton ◽  
Hubert Morin
Keyword(s):  
Radial Growth ◽  
Growth Patterns ◽  
Radial Increment ◽  
Forest Types ◽  
Eastern Canada ◽  
Old Growth ◽  
Growth Trends ◽  
Silvicultural Treatments ◽  
Old Growth Forest ◽  
Old Growth Forests

Research Highlights: Radial growth patterns of trees growing in old-growth boreal forests in eastern Canada can be grouped into a small number of simple patterns that are specific to different old-growth forest types or successional stages. Background and Objectives: Identifying the main radial growth trends in old-growth forests could help to develop silvicultural treatments that mimic the complex dynamics of old-growth forests. Therefore, this study aimed to identify the main radial growth patterns and determine how their frequencies change during forest succession in old-growth forests, focusing on boreal landscapes in eastern Canada. Materials and Methods: We used dendrochronological data sampled from 21 old-growth stands in the province of Quebec, Canada. Tree-ring chronologies were simplified into chronologies of equal length to retain only primary growth trends. We used k-means clustering to identify individual growth patterns and the difference in growth-pattern frequency within the studied stands. We then used non-parametric analyses of variance to compare tree or stand characteristics among the clusters. Results: We identified six different growth patterns corresponding to four old-growth forest types, from stands at the canopy breakup stage to true old-growth stands (i.e., when all the pioneer cohort had disappeared). Secondary disturbances of low or moderate severity drove these growth patterns. Overall, the growth patterns were relatively simple and could be generally separated into two main phases (e.g., a phase of limited radial increment size due to juvenile suppression and a phase of increased radial increment size following a growth release). Conclusions: The complexity of old-growth forest dynamics was observed mainly at the stand level, not at the tree level. The growth patterns observed in true old-growth forests were similar to those observed following partial or stem-selection cuts in boreal stands; thus, these silvicultural treatments may be effective in mimicking old-growth dynamics.

scholarly journals Comparison of the Radial Growth Response of Picea crassifolia to Climate Change in Different Regions of the Central and Eastern Qilian Mountains

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1015
Author(s):  
Xuan Wu ◽  
Liang Jiao ◽  
Dashi Du ◽  
Changliang Qi ◽  
Ruhong Xue
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Central Region ◽  
Radial Growth ◽  
Growing Season ◽  
Qilian Mountains ◽  
Growth Patterns ◽  
Total Precipitation ◽  
Picea Crassifolia ◽  
The Qilian Mountains

It is important to explore the responses of radial tree growth in different regions to understand growth patterns and to enhance forest management and protection with climate change. We constructed tree ring width chronologies of Picea crassifolia from different regions of the Qilian Mountains of northwest China. We used Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth–climate relationship, while spatial correlation is the result of further testing the first two terms in space. The conclusions were as follows: (1) Radial growth had different trends, showing an increasing followed by a decreasing trend in the central region, a continuously increasing trend in the eastern region, and a gradually decreasing trend in the isolated mountain. (2) Radial tree growth in the central region and isolated mountains was constrained by drought stress, and tree growth in the central region was significantly negatively correlated with growing season temperature. Isolated mountains showed a significant negative correlation with mean minimum of growing season and a significant positive correlation with total precipitation. (3) Temporal dynamic responses of radial growth in the central region to the temperatures and SPEI (the standardized precipitation evapotranspiration index) in the growing season were unstable, the isolated mountains to total precipitation was unstable, and that to SPEI was stable. The results of this study suggest that scientific management and maintenance plans of the forest ecosystem should be developed according to the response and growth patterns of the Qinghai spruce to climate change in different regions of the Qilian Mountains.

scholarly journals Impacts of increasing fine fuel loads on acorn germination and early growth of oak seedlings

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Rachel E. Nation ◽  
Heather D. Alexander ◽  
Geoff Denny ◽  
Jennifer K. McDaniel ◽  
Alison K. Paulson
Keyword(s):  
Prescribed Fire ◽  
Germination Rate ◽  
Growth Patterns ◽  
Leaf Number ◽  
Fuel Load ◽  
Quercus Alba ◽  
White Oak ◽  
Fuel Treatment ◽  
Basal Diameter ◽  
Fuel Loads

Abstract Background Prescribed fire is increasingly used to restore and maintain upland oak (Quercus L. spp.) ecosystems in the central and eastern US. However, little is known about how prescribed fire affects recently fallen acorns under different fine fuel loads, which can vary with stand composition and basal area, burn season, and fire frequency. We conducted plot-level (1 m2) burns in an upland oak stand in northern Mississippi, USA, during December 2018, using single (i.e., ambient), double, and triple fine fuel loads, representative of those in nearby unburned and recently fire-treated, closed-canopy stands. Pre burn, we placed 30 acorns each of white oak (Quercus alba L.) and Shumard oak (Quercus shumardii Buckley) ~1 cm below the litter surface in five plots of each fuel treatment. Immediately post burn, we planted unburned and burned acorns in a greenhouse. After ~50% of each species’ unburned acorns germinated, we measured percent germination and height, basal diameter, and leaf number of germinating seedlings weekly for 11 weeks. Then, we harvested seedlings to determine above- and belowground biomass. Results The single fuel treatment reduced acorn germination rates of both species to ~40% compared to ~88% in unburned acorns. When burned in double and triple fuel loads, acorns of both species had a <5% germination rate. There was no difference in basal diameter, leaf number, or biomass of seedlings from burned versus unburned acorns for either species. However, seedlings originating from burned acorns of both species were ~11% shorter than those from unburned acorns. Thus, both species responded similarly to fuel load treatments. Conclusions Acorns of both species exhibited greater survival with lower fine fuel loads, and consequently lower percent fuel consumption. Acorns germinating post fire generally produced seedlings with growth patterns similar to seedlings originating from unburned acorns. These findings indicate that regular, repeated prescribed fires or canopy reductions that limit fine fuel accumulation and create heterogeneous fuel beds are likely to increase acorn germination rates relative to unburned sites or those with recently introduced fire.

scholarly journals A synthesis of radial growth patterns preceding tree mortality

2016 ◽  
Vol 23 (4) ◽  
pp. 1675-1690 ◽  
Author(s):  
Maxime Cailleret ◽  
Steven Jansen ◽  
Elisabeth M. R. Robert ◽  
Lucía Desoto ◽  
Tuomas Aakala ◽  
...  
Keyword(s):  
Radial Growth ◽  
Tree Mortality ◽  
Growth Patterns

scholarly journals Early indications of drought impacts on forests in the southeastern United States

2015 ◽  
Vol 91 (04) ◽  
pp. 376-383 ◽  
Author(s):  
Michael K. Crosby ◽  
Zhaofei Fan ◽  
Martin A. Spetich ◽  
Theodor D. Leininger ◽  
Xingang Fan
Keyword(s):  
United States ◽  
Forest Type ◽  
Southeastern United States ◽  
Forest Health ◽  
Classification And Regression Tree ◽  
Future Research ◽  
Red Oak ◽  
White Oak ◽  
Cart Analysis ◽  
Crown Dieback

In the southeastern United States, drought can pose a significant threat to forests by reducing the amount of available water, thereby stressing trees. Destructive changes in crown conditions provide the first visible indication of a problem in a forested area, making it a useful indicator for problems within an ecosystem. Forest Health and Monitoring (FHM) and Palmer's Drought Severity Index (PDSI) data from 11 states in the southeastern United States were obtained in an effort to determine the role that drought, forest type, and ecoregion have in indicating differences in crown dieback. Analyses were conducted by species groups using classification and regression tree (CART) analysis. The greatest amount of total relative crown dieback occurred in red oak (18%), followed by other hardwoods (14%), and white oak (11%). Relative crown dieback varied by forest type and ecoregion with a relationship to drought in both red oak and white oak. This information will be useful for focusing future research and modeling efforts to predict forest health conditions affected by changing climate variables.

scholarly journals Growth features of different forms of scots pine in the shrub-sphagnum forest type estuary of the Onega River

2020 ◽  
Vol 10 (2) ◽  
pp. 151-169
Author(s):  
Ekaterina A. Pinaevskaya ◽  
Sergey N. Tarkhanov ◽  
Aleksandr S. Pakhov
Keyword(s):  
Scots Pine ◽  
Radial Growth ◽  
Forest Type ◽  
Northern Taiga ◽  
Morphometric Characteristics ◽  
North West ◽  
The North ◽  
Pine Tree ◽  
European Part Of Russia ◽  
Growth Features

Pinus sylvestris L. is the main tree species of forest ecosystems in the European North of Russia, therefore, in-depth studies of the diversity of forms and growth processes of this plant are important. Forms in pine stand out according to morphological and other characteristics. In conditions of prolonged excessive soil moisture, the joint growth of various forms of pine is observed. The aim of the work is to study the growth of various forms of pine according to morphostructural characteristics in the shrub-sphagnum forest type estuary of the Onega River. Investigations of tree growth (according to the form of seed cone scales apophysis and crown habit) were carried out in shrub-sphagnum pine forests of different ages in the north-west of the European part of Russia (northern taiga subzone). Morphometric measurements of the vegetative and generative spheres in the forms of scots pine were made. It is established that the advantage in morphometric characteristics, average values ​​of radial growth, late and early wood has a pine tree with a «convex» apophysis form. The advantage with respect to the morphometric characteristics of the trunk and crown is form with «ordinary» crown habit. The «ordinary» form has larger cones, a larger value of radial growth and macrostructural parameters of wood compared to the «swamp».

scholarly journals Timeline of Leaf and Cambial Phenology in Relation to Development of Initial Conduits in Xylem and Phloem in Three Coexisting Sub-Mediterranean Deciduous Tree Species

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1104
Author(s):  
Jožica Gričar ◽  
Andreja Vedenik ◽  
Gregor Skoberne ◽  
Polona Hafner ◽  
Peter Prislan
Keyword(s):  
Tree Species ◽  
Leaf Development ◽  
Radial Growth ◽  
Secondary Growth ◽  
Growth Patterns ◽  
Deciduous Tree ◽  
Cambial Cell ◽  
Cell Production ◽  
Sieve Tubes ◽  
Earlywood Vessels

It is unclear how the anticipated climate change will affect the timing of phenology of different tree organs/tissues and thus the whole-tree functioning. We examined the timing of leaf phenology and secondary growth in three coexisting deciduous tree species (Quercus pubescens Willd., Fraxinus ornus L. and Ostrya carpinifolia Scop) from a sub-Mediterranean region in 2019. In addition, we investigated the relationship between leaf and cambial phenology and the onset of the potential functioning of initial conduits, as determined by the completed differentiation process (vessels) or final size (sieve tubes). For this purpose, leaf development was monitored and the microcores of cambium and the youngest phloem and xylem increments were repeatedly collected at 7–10-day intervals during the growing season. The results revealed differences in the timing of leaf development and seasonal radial growth patterns in spring among the studied tree species, depending on wood porosity. We found that cambial cell production started in all cases in the first half of March. However, in ring-porous Q. pubescens and F. ornus, radial growth in the stem occurred more than a month before buds were swollen, whereas in diffuse-porous O. carpinifolia, these two events were detected at almost the same time. The end of cambial cell production occurred earliest in F. ornus (mid-July) and two weeks later also in the other two species. The widest initial earlywood vessels and early phloem sieve tubes were found in Q. pubescens, the narrowest initial earlywood vessels in O. carpinifolia and the narrowest early phloem sieve tubes in F. ornus. This indicates differences in the efficiency of conducting systems among the studied species. This novel approach of studying phloem phenology and anatomy in relation to leaf and xylem development contributes to a better understanding of how different tree species adapt their structure of secondary vascular tissues in response to environmental change.

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