Spatially random mortality in old-growth red pine forests of northern Minnesota

2012 ◽  
Vol 42 (5) ◽  
pp. 899-907 ◽  
Author(s):  
Tuomas Aakala ◽  
Shawn Fraver ◽  
Brian J. Palik ◽  
Anthony W. D’Amato
Keyword(s):  
Spatial Distribution ◽  
Tree Mortality ◽  
Empirical Studies ◽  
Pair Correlation ◽  
Growth Conditions ◽  
Initial Distribution ◽  
Red Pine ◽  
Old Growth ◽  
Dead Trees ◽  
Old Growth Forests

Characterizing the spatial distribution of tree mortality is critical to understanding forest dynamics, but empirical studies on these patterns under old-growth conditions are rare. This rarity is due in part to low mortality rates in old-growth forests, the study of which necessitates long observation periods, and the confounding influence of tree in-growth during such time spans. Here, we studied mortality of red pine ( Pinus resinosa Ait.) in five old-growth stands in Minnesota, USA, demonstrating the use of preexisting information of cohort age structures to account for in-growth after the most recent cohort establishment. Analyses of spatial point patterns, using both Ripley’s K-function and the pair correlation function, showed that tree mortality was essentially a random process, without evidence of contagious mortality patterns that are often expected for old-growth forests. Our analyses further demonstrated in practice that the distribution of dead trees may differ from that of the tree mortality events, which are constrained to occur within the initial distribution, and how mortality patterns can shape the spatial distribution of mature living trees, often attributed to aggregated regeneration patterns. These findings emphasize the need to disentangle the influence of the initial distribution of trees from that of actual tree mortality events.

Trees dying standing in the northeastern boreal old-growth forests of Quebec: spatial patterns, rates, and temporal variation

2007 ◽  
Vol 37 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Tuomas Aakala ◽  
Timo Kuuluvainen ◽  
Louis De Grandpré ◽  
Sylvie Gauthier
Keyword(s):  
Temporal Variation ◽  
Spatial Patterns ◽  
Tree Mortality ◽  
Abies Balsamea ◽  
Structural Complexity ◽  
Habitat Diversity ◽  
Old Growth ◽  
Dead Trees ◽  
Old Growth Forests ◽  
Standing Trees

Spatial patterns, rates, and temporal variation of standing-tree mortality were studied in unmanaged boreal old-growth forests of northeastern Quebec. The study was carried out by sampling living and dead trees within 15 transects (400 m long, 40 m wide). The transects lay in stands that were classified according to their species composition in three types: dominated by black spruce, Picea mariana (Mill.) BSP; mixed P. mariana and balsam fir, Abies balsamea (L.) Mill.; and dominated by A. balsamea. Spatial patterns were analysed using Ripley's K function. The year of death was cross-dated using 190 sample discs extracted from dead standing A. balsamea and P. mariana to assess the rates and temporal variation of mortality. The spatial patterns of standing dead trees in P. mariana stands were predominantly clustered. The spatial patterns of large dead trees (>19 cm diameter at breast height (1.3 m height; DBH)) in mixed and A. balsamea-dominated stands were mainly random, with few stands showing clustered patterns. Small dead trees (9–19 cm DBH) in these stands were generally more clustered than larger trees. Tree mortality varied from year to year, though some mortality was observed in all the studied stand types for almost every year. Standing trees that had recently died accounted for 62%, 48%, and 51% of overall mortality in P. mariana-dominated, mixed, and A. balsamea-dominated stands, respectively. The results of this study indicate that mortality of standing trees outside of episodic mortality events (such as insect outbreaks) is an important process in the creation of structural complexity and habitat diversity in these stands.

scholarly journals Spatial aspects of tree mortality strongly differ between young and old-growth forests

Ecology ◽  
2015 ◽  
Vol 96 (11) ◽  
pp. 2855-2861 ◽  
Author(s):  
Andrew J. Larson ◽  
James A. Lutz ◽  
Daniel C. Donato ◽  
James A. Freund ◽  
Mark E. Swanson ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Old Growth ◽  
Old Growth Forests

Adapting forestry practices to address old-growth concerns in the Great Lakes–St.Lawrence forests of Ontario

2003 ◽  
Vol 79 (3) ◽  
pp. 613-620 ◽  
Author(s):  
Fred Pinto
Keyword(s):  
Great Lakes ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Natural Disturbance ◽  
Red Pine ◽  
Forest Composition ◽  
White Birch ◽  
Site Factors ◽  
Old Growth ◽  
Old Growth Forests

The Great Lakes–St. Lawrence forest, particularly the eastern white (Pinus strobus L.) and red pine (P. resinosa Ait.) forests around Temagami and Sault Ste. Marie, was the centre of controversy regarding the treatment of old-growth forests in Ontario in the 1980s and 1990s. The controversy stemmed from changes in forest composition and structure occurring in the forest. For example, the Ontario public was concerned with the obvious reduction in numbers of large eastern white and red pine trees and their replacement with small, often poor quality, white birch (Betula papyrifera Marsh.), aspen (Populus tremuloides Michx.), and jack pine (Pinus banksiana Lamb.) trees. Over the past two decades, changes in legislation, forest planning and stand prescriptions have been made in Ontario and practices at the forest and stand levels have also changed significantly. The new practices are based on linking forest activities to a better understanding of ecological processes in the forest; in particular, linking harvest and regeneration activities to our current understanding of natural disturbances and plant adaptations. These practices attempt to match more closely the conditions found in forests with a heritage of natural disturbance and reproduction, i.e., old-growth forests. For example, stand-initiating disturbances result in some trees being killed, some being damaged, and some surviving. The new harvest practices consider tree adaptations and site factors when deciding whether a tree will be cut or not. This paper provides examples of how this ecosystem-based forestry is being applied in Ontario. Key words: old growth in Ontario, conservation of old growth, application of old growth conservation practices, stand practices for old growth, landscape practices for old growth

Recent tree mortality and recruitment in mature and old-growth forests in western Washington

2015 ◽  
Vol 336 ◽  
pp. 109-118 ◽  
Author(s):  
Steven A. Acker ◽  
John R. Boetsch ◽  
Mignonne Bivin ◽  
Lou Whiteaker ◽  
Carla Cole ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington

scholarly journals An evaluation of multi-species empirical tree mortality algorithms for dynamic vegetation modelling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy Thrippleton ◽  
Lisa Hülsmann ◽  
Maxime Cailleret ◽  
Harald Bugmann
Keyword(s):  
Forest Dynamics ◽  
Tree Mortality ◽  
Basal Area ◽  
Present Climate ◽  
Old Growth ◽  
Explanatory Variables ◽  
Vegetation Modelling ◽  
Old Growth Forests ◽  
Vegetation Models ◽  
Multiple Species

AbstractTree mortality is key for projecting forest dynamics, but difficult to portray in dynamic vegetation models (DVMs). Empirical mortality algorithms (MAs) are often considered promising, but little is known about DVM robustness when employing MAs of various structures and origins for multiple species. We analysed empirical MAs for a suite of European tree species within a consistent DVM framework under present and future climates in two climatically different study areas in Switzerland and evaluated their performance using empirical data from old-growth forests across Europe. DVM projections under present climate showed substantial variations when using alternative empirical MAs for the same species. Under climate change, DVM projections showed partly contrasting mortality responses for the same species. These opposing patterns were associated with MA structures (i.e. explanatory variables) and occurred independent of species ecological characteristics. When comparing simulated forest structure with data from old-growth forests, we found frequent overestimations of basal area, which can lead to flawed projections of carbon sequestration and other ecosystem services. While using empirical MAs in DVMs may appear promising, our results emphasize the importance of selecting them cautiously. We therefore synthesize our insights into a guideline for the appropriate use of empirical MAs in DVM applications.

Lichen communities in two old-growth pine (Pinus) forests

2014 ◽  
Vol 46 (5) ◽  
pp. 697-709 ◽  
Author(s):  
Christopher WAGNER ◽  
Lyndsay J. SCHRAM ◽  
Richard Troy McMULLIN ◽  
Shelley L. HUNT ◽  
Madhur ANAND
Keyword(s):  
Woody Debris ◽  
Pine Forest ◽  
Lichen Species ◽  
Red Pine ◽  
White Pine ◽  
Old Growth ◽  
Lichen Diversity ◽  
Old Growth Forest ◽  
Significant Difference ◽  
Old Growth Forests

AbstractMany lichen species have specific environmental requirements for colonization. Old-growth forests contain microhabitats required by a particular suite of lichens. In Ontario, Canada, old-growth forests are increasingly uncommon and the lichen communities within some of these forests are not well known. To better understand the lichen communities that inhabit old-growth forests in the province, we examined the lichen biota on coarse woody debris (CWD) and trees in a red pine (Pinus resinosa) and a white pine (Pinus strobus) dominated stand in northern Ontario. Lichen diversity was assessed on different forms of CWD and trees in each forest. Lichen diversity did not differ significantly between CWD types in the red pine forest, but was significantly different in the white pine forest. There was no significant difference in lichen diversity amongst different decay stages of CWD in either forest. In both forests, lichen communities on stumps, logs, and snags differed from lichen communities present on trees. A variety of CWD types is important for overall lichen species richness in the red pine forest. Our results demonstrate to land managers that different types of old-growth forests are ecologically unique, even those dominated by tree species in the same genus. Management of an old-growth forest should suit its individual ecology.

Do forests treated by partial cutting provide growth conditions similar to old-growth forests for epiphytic lichens?

2013 ◽  
Vol 159 ◽  
pp. 458-467 ◽  
Author(s):  
Catherine Boudreault ◽  
Darwyn Coxson ◽  
Yves Bergeron ◽  
Susan Stevenson ◽  
Mathieu Bouchard
Keyword(s):  
Growth Conditions ◽  
Epiphytic Lichens ◽  
Old Growth ◽  
Partial Cutting ◽  
Old Growth Forests

Standing dead trees and their decay-class dynamics in the northeastern boreal old-growth forests of Quebec

2008 ◽  
Vol 255 (3-4) ◽  
pp. 410-420 ◽  
Author(s):  
Tuomas Aakala ◽  
Timo Kuuluvainen ◽  
Sylvie Gauthier ◽  
Louis De Grandpré
Keyword(s):  
Old Growth ◽  
Decay Class ◽  
Dead Trees ◽  
Old Growth Forests ◽  
Standing Dead ◽  
Standing Dead Trees

Old-growth forests in the temperate deciduous zone of Quebec: Identification and evaluation for conservation and research purposes

2003 ◽  
Vol 79 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Normand Villeneuve ◽  
Jacques Brisson
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Forest Cover ◽  
Deciduous Forest ◽  
Control Site ◽  
Old Growth ◽  
Forest Zone ◽  
Dead Trees ◽  
Old Growth Forests ◽  
Shade Tolerant Species

The Quebec Department of Natural Resources (Ministère des ressources naturelles du Québec) is working to identify and protect old-growth forests in the deciduous forest zone of the province. A total of 88 sites was visited and a multivariate analysis of the main attributes of old growth allowed the development of quantitative definitions and criteria for identifying old-growth sugar maple (Acer saccharum), eastern hemlock (Tsuga canadensis), eastern white pine (Pinus strobus), eastern white-cedar (Thuja occidentalis), and red spruce (Picea rubens) stands. Life expectancy of various species according to environment was determined through a statistical analysis of 21 500 study trees taken from the province's forest inventory. Four different identification criteria for old-growth forests were developed that include a number of indicators for old growth. Along with advanced age of forest cover, the criteria that best reflected the nature of old-growth forests were the presence of large dead trees, low cutting intensity, and the importance of shade-tolerant species. Old-growth forests identified during this validation work occupy roughly 60 km2 in Quebec's deciduous forest zone. Among other things, old-growth sugar maple stands of over 400 years old were discovered, containing stems with a diameter at breast height of 140 cm and a height of over 38 m. The very great potential of many of these exceptional forests for scientific research and biodiversity conservation is illustrated by the work carried out in the Boisé des Muir. Despite its small size, this sugar maple stand, which is over 300 years old, has advanced knowledge in fields as varied as forest dynamics, biodiversity, and climate studies, and has also served as a control site for various scientific studies. Key words: old-growth forests, definitions, criteria, indicators, inventory, Quebec, conservation, scientific value

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