Author: Timothy Edward ParshallPublisher:
ISBN:
Category :
Languages : en
Pages : 98
Book Description
Canopy Disturbances Mediate Species Composition Changes in a Northern Hemlock-hardwood Forest Mosaic
Author: Timothy Edward ParshallPublisher:
ISBN:
Category :
Languages : en
Pages : 98
Book Description
Canadian Journal of Forest Research
Author: Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 692
Book Description
Long-term Avian Community Response to Hemlock Decline
Author: Matthew ToeniesPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Forest biomes face increasing rates of disturbance from many causes, including climate change, introduced pests, and shifting fire regimes, as well interactions between multiple factors. In particular, the introduction of exotic forest pests is increasing globally, frequently resulting in decline and die-off of affected forest types. The loss of foundational forest species can drastically change the structure and composition of vegetation communities in forests, a phenomenon that holds strong implications for avian communities. However, little research has focused on the long-term effects of forest die-off at a community-wide scale. To examine the response of bird communities to forest die-off, we studied the community associated with declining eastern hemlock (Tsuga canadensis) forests affected by the introduced hemlock woolly adelgid (Adelges tsugae). We conducted variable-radius point counts to survey bird communities in both hemlock and hardwood stands in 2000, during early stages of adelgid infestation, and again in 2015 and 2016, following significant hemlock decline. We also measured the severity of hemlock decline and associated vegetation variables in the same hemlock stands where avian surveys occurred. We used multi-species occupancy models to examine species-specific and species group responses to hemlock decline. Results showed that hemlock basal area declined to varying degrees across the hemlock stands, and that hemlock decline was correlated with current vegetation structure, including an increased deciduous understory. Hemlock-associated bird species declined between the two time periods, while all other species groups responded positively, with the strongest responses in species associated with the shrub-layer, forest edge, and mature deciduous habitat. Species composition in hemlock and hardwood stands became more correlated over time, highlighting a trend toward homogenization of the avian community as the unique species assemblages in hemlock stands give way to the avian community of the surrounding hardwood landscape. Where hemlock-associated species persisted, their presence was correlated with the combined effect of greater hemlock basal area and better hemlock condition. Our results demonstrate that the decline and die-off of foundational forest species can restructure vegetation communities and their associated avian communities over time, with strong implications for forest type specialists. Due to regional variation in patterns of forest die-off and community composition, understanding impacts on forest-dependent communities requires examining response at broad spatial and temporal scales. To determine how the responses to forest die-off that we observed in the avian community may vary across a large regional scale, we examined bird communities in hemlock stands at four sites across the range of hemlock woolly adelgid in the northeastern/mid-Appalachian regions of the United States. We surveyed the avian community in earlier stages of infestation and again following hemlock decline, and analyzed this data using a multi-species occupancy modeling approach. Despite variability among sites in characteristics of the avian community and of the die-off itself, changes in species richness over time were similar across all sites. Hemlock-associated bird species declined at all sites, with concurrent increases in other species groups, especially those associated with forest edge and shrub-layer habitats. Finer-scale variation in the magnitude of avian response coincided with the varying stages of hemlock decline across sites. Species-specific trends showed that Acadian Flycatcher declined most consistently across this large regional scale. Understanding these patterns is critical to predicting and preparing for changes to not only forested landscapes affected by the loss of hemlock, but also for those that will experience similar die-offs as forest pest introductions increase globally.
Effects of the Canopy Opening on the Understory of an Old Growth Eastern Hemlock-northern Hardwood Forest in South-central Pennsylvania
Author: Mark J. LewisPublisher:
ISBN:
Category : Eastern hemlock
Languages : en
Pages : 128
Book Description
Structural Changes in an Old Growth Eastern Hemlock-northern Hardwood Forest Following Invasion by the Hemlock Woolly Adelgid
Author: Leonard G. CagePublisher:
ISBN:
Category : Buchanan National Forest (Pa.)
Languages : en
Pages : 122
Book Description
Invasive Species in Forests and Rangelands of the United States
Author: Therese M. PolandPublisher: Springer Nature
ISBN: 3030453677
Category : Science
Languages : en
Pages : 455
Book Description
This open access book describes the serious threat of invasive species to native ecosystems. Invasive species have caused and will continue to cause enormous ecological and economic damage with ever increasing world trade. This multi-disciplinary book, written by over 100 national experts, presents the latest research on a wide range of natural science and social science fields that explore the ecology, impacts, and practical tools for management of invasive species. It covers species of all taxonomic groups from insects and pathogens, to plants, vertebrates, and aquatic organisms that impact a diversity of habitats in forests, rangelands and grasslands of the United States. It is well-illustrated, provides summaries of the most important invasive species and issues impacting all regions of the country, and includes a comprehensive primary reference list for each topic. This scientific synthesis provides the cultural, economic, scientific and social context for addressing environmental challenges posed by invasive species and will be a valuable resource for scholars, policy makers, natural resource managers and practitioners.
Pattern and Process in a Forested Ecosystem
Author: F.Herbert BormannPublisher: Springer Science & Business Media
ISBN: 1461262321
Category : Science
Languages : en
Pages : 265
Book Description
The advent of ecosystem ecology has created great difficulties for ecologists primarily trained as biologists, since inevitably as the field grew, it absorbed components of other disciplines relatively foreign to most ecologists yet vital to the understanding of the structure and function of ecosystems. From the point of view of the biological ecologist struggling to understand the enormous complexity of the biological functions within an ecosystem, the added necessity of integrating biology with geochemis try, hydrology, micrometeorology, geomorphology, pedology, and applied sciences (like silviculture and land use management) often has appeared as an impossible requirement. Ecologists have frequently responded by limiting their perspective to biology with the result that the modeling of species interactions is sometimes considered as modeling ecosystems, or modeling the living fraction of the ecosystems is considered as modeling whole ecosystems. Such of course is not the case, since understanding the structure and function of ecosystems requires sound understanding of inanimate as well as animate processes and often neither can be under stood without the other. About 15 years ago, a view of ecology somewhat different from most then prevailing, coupled with a strong dose of naivete and a sense of exploration, lead us to believe that consideration of the inanimate side of ecosystem function rather than being just one more annoying complexity might provide exceptional advantages in the study of ecosystems. To examine this possibility, we took two steps which occurred more or less simultaneously.
Causes and Consequences of Species Diversity in Forest Ecosystems
Author: Aaron M. EllisonPublisher: MDPI
ISBN: 3039213091
Category : Science
Languages : en
Pages : 274
Book Description
This book is a printed edition of the Special Issue Causes and Consequences of Species Diversity in Forest Ecosystems that was published in Forests
Ecology and Decline of Red Spruce in the Eastern United States
Author: Mary B. AdamsPublisher: Springer Science & Business Media
ISBN: 1461229065
Category : Science
Languages : en
Pages : 427
Book Description
In the early 1980s there were several published reports of recent, unexplained increases in mortality of red spruce in the Adirondack Mountains and the northern Appalachian Mountains of the eastern United States. These reports coincided with documentation of reductions in radial growth of several species of pine in the southeastern United States, and with the severe, rapid, and widespread decline of Norway spruce, silver fir, and some hardwoods in central Europe. In all of these instances, atmospheric deposition was hypothesized as the cause of the decline. (Throughout this volume, we use the term "decline" to refer to a loosely synchronized regional-scale deterioration of tree health which is brought about by a combination of stress factors. These may be biotic or abiotic in nature, and the combinations may differ from site to site. ) Heated public debate about the causes and possible cures for these forest declines ensued. Through the course of this debate, it became clear that information about forest health and air pollution effects on forests was inadequate to meet policymakers' needs. Ecology and Decline of Red Spruce in the Eastern United States addresses that gap for eastern spruce fir forests and represents the culmination of a great deal of research conducted in recent years. The focus is on red spruce because the decline of red spruce was both dramatic and inexplicable and because of the great amount of information gathered on red spruce.
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