Treesearch

Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the "stand age" variable from the US Forest Service Forest Inventory and Analysis (FIA) program reflects the timing of historical high-severity (i.e. stand-replacing) fire in...

Recent population declines in amphibians associated with mortality in early life stages highlight the need for a better understanding of the environmental factors related to successful survival to metamorphosis. In our study, we closely examine the relative importance of environmental factors to three stages of recruitment for Cascade frogs (Rana cascadae), a declining amphibian, in high-elevation wet meadows. Our results show that local dynamics are strongly associated with breeding site selection, the number of egg masses, and the number of individuals that survive to metamorphosis per...

Forest management today often seeks to restore ecological integrity and enhance human well-being by increasing forest complexity, resilience, and functionality. However, effective and financially expedient monitoring of forest complexity is challenging. In this study, we developed a practical and inexpensive technique to measure horizontal forest complexity. This monitoring method uses intuitively understandable data (imagery) and facilitates stakeholder participation in the adaptive management process within collaborative projects. We used this technique to determine if current restoration...

Massive amounts of agricultural and industrial water worldwide are polluted by different types of contaminants that harm the environment and impact human health. Removing the contaminants from effluents by adsorbent materials made from abundant, inexpensive polysaccharides is a feasible approach to deal with this problem. In this research, alginate beads combined with two types of cellulose, starch or xylan were synthesized. Their average diameters in air- and freeze-dried conditions were assessed by optical microscopy. Differences in morphology were observed by scanning electron microscopy...

Forest resilience to climate change is a topic of national concern as our standing assets and future forestsare important to our livelihood. Many tree species are predicted to decline or disappear while othersmay be able to adapt or migrate. Efforts to quantify and disseminate the current condition of forests areurgently needed to guide management and policy. Here, we develop a new indicator to summarize rawdensity-independent mortality of forested stands by species from the last decade of the 20th century tothe first decade of the 21st century using forest inventory data. We define...

Decades of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) overpopulation have dramatically homogenized forests across much of the eastern United States, creating depauperate forest understory communities. The rate at which these communities recover once deer browsing has been reduced remains an open question. We evaluate overbrowsing legacy effects by examining how forest herbaceous layers respond in terms of biodiversity, density, and community composition over 11 years using exclosures and control plots within a mature beech–maple forest. Although little recovery occurred...

Salvage logging following windthrow is common throughout forests worldwide even though the practice is often considered inimical to forest recovery. Because salvaging removes trees, crushes seedlings, and compacts soils, many warn this practice may delay succession, suppress diversity, and alter composition. Here, over 8 yr following windthrow, we experimentally evaluate how salvaging affects tree succession across 11 gaps in Eastern deciduous forests of Pennsylvania, wherein each gap was divided into salvaged and control (unsalvaged) halves. Our gaps vary in size and windthrow severity,...

Large, high severity fires are becoming more prevalent in Sierra Nevada mixed-conifer forests, largely due to heavy fuel loading and forest densification caused by past and current management practices. In post-fire areas distant from seed trees, conifers are often planted to re-establish a forest and to prevent a potential type-conversion to shrub fields. Typical reforestation efforts promote conifer survival and growth by reducing competing shrub cover, yet the effects of these practices on plant species richness and composition are not well understood. We compared the effects of...

1. The Long-Term Ecological Research (LTER) program has not influenced my basic approach to science. 2. The LTER program has reinforced my approach to mentoring, and it has increased my opportunities to mentor students through the LTER-associated Research Experiences for Undergraduates Program. 3. LTER program has greatly enriched my collaborative network and expanded my research in directions that I would not have otherwise pursued; similarly, I have expanded the research and perspectives of my collaborators. 4. My involvement in the LTER program has changed my perspective in reviewing...

Extensive mortality of whitebark pine, beginning in the early to mid-2000s, occurred in the Greater Yellowstone Ecosystem (GYE) of the western USA, primarily from mountain pine beetle but also from other threats such as white pine blister rust. The climatic drivers of this recent mortality and the potential for future whitebark pine mortality from mountain pine beetle are not well understood, yet are important considerations in whether to list whitebark pine as a threatened or endangered species. We sought to increase the understanding of climate influences on mountain pine beetle outbreaks...