Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
9,555
result(s) for
"OLD-GROWTH FORESTS"
Sort by:
Spatial aspects of tree mortality strongly differ between young and old-growth forests
Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (<60-year-old) and old-growth (>300-year-old)
Abies amabilis
forests. Trees in young forests died at a rate of 4.42% per year, whereas trees in old-growth forests died at 0.60% per year. Tree mortality in young forests was significantly aggregated, strongly density dependent, and caused live tree patterns to become more uniform through time. Mortality in old-growth forests was spatially aggregated, but was density independent and did not change the spatial pattern of surviving trees. These results extend current theory by demonstrating that density-dependent competitive mortality leading to increasingly uniform tree spacing in young forests ultimately transitions late in succession to a more diverse tree mortality regime that maintains spatial heterogeneity through time.
Journal Article
The power of trees : how ancient forests can save us if we let them
\"From the international bestselling author of The Hidden Life of Trees. An illuminating manifesto on ancient forests: how they adapt to climate change by passing their wisdom through generations, and why our future lies in protecting them. In his beloved book The Hidden Life of Trees, Peter Wohlleben revealed astonishing discoveries about the social networks of trees and how they communicate. Now, in The Power of Trees, he turns to their future, with a searing critique of forestry management, tree planting, and the exploitation of old growth forests. As human-caused climate change devastates the planet, forests play a critical role in keeping it habitable. While politicians and business leaders would have us believe that cutting down forests can be offset by mass tree planting, Wohlleben offers a warning: many tree planting campaigns lead to ecological disaster. Not only are these trees more susceptible to disease, flooding, fires, and landslides, we need to understand that forests are more than simply a collection of trees. Instead, they are ecosystems that consist of thousands of species, from animals to fungi and bacteria. The way to save trees, and ourselves? Step aside and let forests--which are naturally better equipped to face environmental challenges--heal themselves. With the warmth and wonder familiar to readers from his previous books, Wohlleben also shares emerging scientific research about how forests shape climates both locally and across continents; that trees adapt to changing environmental conditions through passing knowledge down to their offspring; and how old growth may in fact have the most survival strategies for climate change. At the heart of The Power of Trees lies Wohlleben's passionate plea: that our survival is dependent on trusting ancient forests, and allowing them to thrive.\"-- Provided by publisher.
Book
Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink
Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (
Liriodendron tulipifera
) store the most live biomass, while the mixed oak (
Quercus
spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.
Journal Article
In search of the old ones : an odyssey among ancient trees
\"An extraordinary journey to visit the oldest trees in the United States that beautifully reveals the connection between humans and natural history\"-- Provided by publisher.
Book
Disturbance, life history traits, and dynamics in an old-growth forest landscape of southeastern Europe
Much of our understanding of natural forest dynamics in the temperate region of Europe is based on observational studies in old-growth remnants that have emphasized small-scale gap dynamics and equilibrium stand structure and composition. Relatively little attention has been given to the role of infrequent disturbance events in forest dynamics. In this study, we analyzed dendroecological data from four stands and three windthrow patches in an old-growth landscape in the Dinaric Mountains of Bosnia and Herzegovina to examine disturbance history, tree life history traits, and compositional dynamics. Over all stands, most decades during the past 340 years experienced less than 10% canopy loss, yet each stand showed evidence of periodic intermediate-severity disturbances that removed >40% of the canopy, some of which were synchronized over the study area landscape. Analysis of radial growth patterns indicated several life history differences among the dominant canopy trees; beech was markedly older than fir, while growth patterns of dead and dying trees suggested that fir was able to tolerate longer periods of suppressed growth in shade. Maple had the fastest radial growth and accessed the canopy primarily through rapid early growth in canopy gaps, whereas most beech and fir experienced a period of suppressed growth prior to canopy accession. Peaks in disturbance were roughly linked to increased recruitment, but mainly of shade-tolerant beech and fir; less tolerant species (i.e., maple, ash, and elm) recruited successfully on some of the windthown sites where advance regeneration of beech and fir was less abundant. The results challenge the traditional notions of stability in temperate old-growth forests of Europe and highlight the nonequilibrial nature of canopy composition due to unique histories of disturbance and tree life history differences. These findings provide valuable information for developing natural disturbance-based silvicultural systems, as well as insight into maintaining less shade-tolerant, but valuable broadleaved trees in temperate forests of Europe.
Journal Article
Larger fragments have more late-successional species of woody plants than smaller fragments after 50 years of secondary succession
1. Most fragmentation research focuses on the effects of carving up old-growth forests, but less is known about influences of habitat fragmentation on secondary succession in patches of regenerating forests. 2. Working with forest dynamics on islands in a vast lake created by a hydroelectric dam in China (the Thousand Island Lake), we sampled 29 islands that were cleared of forest during dam construction in 1959 and then underwent succession. Measurements taken in 2009-2010 and 2014-2015 evaluated community assembly during succession, based on species diversity, functional traits and structural properties. 3. Forests on small islands remained at relatively early stages of compositional succession: species richness was low, and communities were dominated by early-successional species, with few animal-dispersed and shade-tolerant plants. However, these islands had accumulated similar above-ground biomass density to that on larger islands, mostly in the stems of a fast-growing pine species. Island size was the key driver of secondary succession in regenerating forest fragments, while isolation had comparatively little effect. Edge effects were important for species composition and functional composition. 4. Synthesis. Habitat fragmentation resulting from the creation of an artificial lake affected community assembly, with fewer late-successional species on smaller islands. Maintenance of large fragments is critical for the rapid succession of forests. Paradigms on habitat fragmentation effects drawn from old-growth forest studies are unlikely to hold in regenerating forest fragments. Restoration activities should consider landscape patterns to accelerate secondary succession of regenerating forests.
Journal Article
Proximity to an old-growth forest edge and ectomycorrhizal tree islands enhance ectomycorrhizal fungal colonization of Betula lenta L. (black birch) seedlings in secondary forest soils
AimsThe few remaining old-growth forests in the northeastern United States are often comprised of ectomycorrhizal (EM) tree-dominated patches surrounded by arbuscular mycorrhizal (AM) tree-dominated secondary forests. We examined how (1) distance from old growth and tree neighborhood composition influenced EM colonization, fungal richness, and fungal community composition of Betula lenta L. (black birch) seedlings, a common EM tree that colonizes abandoned agricultural fields, and (2) potential effects of EM fungal genera on seedling physiological performance.MethodsWe sampled soils and tree composition from the edge of an EM-dominated old-growth forest into an adjacent AM-dominated secondary forest. We used soils to grow black birch seedlings in a growth chamber bioassay. We measured seedling EM colonization and investigated effects of EM fungi and soil characteristics on seedling physiological performance.ResultsWe identified 20 EM fungal species and found decreases in EM colonization and fungal richness with distance from old growth, with many taxa present only near the edge. Neighborhood EM tree abundance best explained EM colonization while distance interacted with EM tree basal area to best explain EM fungal richness of seedlings. Soils from neighborhoods lacking EM trees resulted in sparse EM colonization of seedlings. We found no clear effects of EM fungal genera on seedling performance, but we detected a slight decrease in seedling photosynthetic rate with distance from old growth.ConclusionsOld-growth forests can be reservoirs of EM fungi, and EM tree patches can function as localized inoculum sources in AM-dominated secondary forests, potentially facilitating EM tree establishment.
Journal Article
Landscape‐level variability in historical disturbance in primary Picea abies mountain forests of the Eastern Carpathians, Romania
QUESTIONS: How have the historical frequency and severity of natural disturbances in primary Picea abies forests varied at the forest stand and landscape level during recent centuries? Is there a relationship between physiographic attributes and historical patterns of disturbance severity in this system? LOCATION: Primary P. abies forests of the Eastern Carpathian Mountains, Romania; a region thought to hold the largest concentration of primary P. abies forests in Europe's temperate zone. METHODS: We used dendrochronological methods applied to many plots over a large area (132 plots representing six stands in two landscapes), thereby providing information at both stand and landscape levels. Evidence of past canopy disturbance was derived from two patterns of radial growth: (1) abrupt, sustained increases in growth (releases) and (2) rapid early growth rates (gap recruitment). These methods were augmented with non‐metric multidimensional scaling to facilitate the interpretation of factors influencing past disturbance. RESULTS: Of the two growth pattern criteria used to assess past disturbance, gap recruitment was the most common, representing 80% of disturbance evidence overall. Disturbance severities varied over the landscape, including stand‐replacing events, as well as low‐ and intermediate‐severity disturbances. More than half of the study plots experienced extreme‐severity disturbances at the plot level, although they were not always synchronized across stands and landscapes. Plots indicating high‐severity disturbances were often spatially clustered (indicating disturbances up to 20 ha), while this tendency was less clear for low‐ and moderate‐severity disturbances. Physiographic attributes such as altitude and land form were only weakly correlated with disturbance severity. Historical documents suggest windstorms as the primary disturbance agent, while the role of bark beetles (Ips typographus) remains unclear. CONCLUSIONS: The historical disturbance regime revealed in this multi‐scale study is characterized by considerable spatial and temporal heterogeneity, which could be seen among plots within stands, among stands within landscapes and between the two landscapes. When the disturbance regime was evaluated at these larger scales, the entire range of disturbance severity was revealed within this landscape.
Journal Article
How temperature, precipitation and stand age control the biomass carbon density of global mature forests
Aim To understand: (1) how temperature, precipitation and stand age control the above-ground biomass carbon density (BCD a ) of mature forests and its macroecology patterns across latitudes; (2) the age threshold for old-growth forests at a global scale. Location Global forests. Methods We compiled a database (897 sites) of mature forests between 80 and 1200 years old. The site data include latitude, longitude, mean annual temperature, mean annual precipitation, forest type, stand age, BCD a , living biomass (above- and below-ground biomass) carbon density and total (living plus dead) biomass carbon density. Based on the site data, we performed regression analyses to show how BCD a changes with climate and forest stand age. Results At a global scale, the highest BCD a of mature forests occurred mainly in the mid-latitude regions where mean annual temperatures were 8–10 °C and mean annual precipitation was between 1000 and 2500 mm. The average BCD a of forests in the stand age class of 450–500 years was higher than those in the other stand age classes. For forests between 80 and 450 years old, which form the majority of mature forests, carbon accumulation was faster in dead biomass than in living biomass. Main conclusions The highest BCD a of mature forests is located in mid-latitude regions with cool temperatures and moderate precipitation. The age threshold for old-growth forests at a global scale should be 450–500 years, which is much older than the previously documented age of 100–200 years. This older age threshold for old-growth forests is probably one of the primary reasons why recent works have concluded that old-growth forests are still carbon sinks.
Journal Article