Treesearch

Las briofitas son un grupo diverso de plantas con distribución mundial, también conocidas como musgos, hepáticas y antocerotes. Estas pequeñas plantas absorben agua por sus hojas (filidios) y tallos (caulidios), y no necesitan raíces o sistema vascular para mantenerse hidratadas. Las briofitas se dispersan por esporas producidas en estructuras especializadas (cápsula/ esporofito) y no producen flores ni semillas. Las briofitas cumplen un rol importante en los bosques capturando agua y nutrientes de la atmósfera, manteniendo la humedad, ayudando a estabilizar el suelo y fijando carbono....

To investigate how source and processing control the composition of “terrestrial” dissolved organic matter (DOM), we combine soil and tree leachates, tree DOM, laboratory bioincubations, and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry in three common landscape types (upland forest, forested wetland, and poor fen) of Southeast Alaska’s temperate rainforest. Tree (Tsuga heterophylla and Picea sitchensis) needles and bark and soil layers from each site were leached, and tree stemflow and throughfall collected to examine DOM sources. Dissolved organic...

canopy defoliation is an important source of disturbance in forest ecosystems that has rarely beenrepresented in large-scale manipulation experiments. Scalable crown to canopy level experimentaldefoliation is needed to disentangle effects of variable intensity, timing, and frequency on forest structure,function, and mortality. We present a novel pressure washing-based defoliation method that can be implemented at the canopy-scale, throughout the canopy volume, targeted to individual leaves/trees, andcompleted within a timeframe of hours/days. Pressure washing proved successful at producing...

Ultramafc ecosystems are renowned for high endemism and habitat specialization. However, most of our understanding of ultramafc plant ecology comes from Medi‑ terranean and temperate climes, raising questions about the generalizability of plant responses to ultramafc soils. This is especially apparent in tropical ultramafc eco‑ systems which exhibit a wide range of endemism and diferentiation between ultra‑ mafc and adjacent non-ultramafc soils. Our objectives were two-fold: 1) synthesize our understanding of tropical ultramafc plant ecology, paying particular attention to generalities...

Black ash wetlands cover approximately 1.2 million ha of wetland forest in the western Great Lakes region, providing critical habitat for wildlife. The future of these wetlands is critically threatened by a variety of factors, including emerald ash borer (Agrilus planipennis; emerald ash borer [EAB]), which has been eliminating native populations of otherwise healthy ash throughout the Great Lakes region since it was discovered in 2002. To quantify the potential impacts of tree mortality from EAB on wildlife communities, we measured seasonal bird, mammal, and amphibian diversity in black...

Determining when a disturbance has occurred, its severity, and when the system recovered, is important tonumerous questions in the aquatic sciences. This problem can be conceptualized as the timing and degree ofperturbation from a typical state, and when the system returns to that typical state. We present an algorithm fordetecting disturbance and recovery designed for high-frequency time series, e.g., data produced by automated sampling devices in instrumented buoys and flux towers. The algorithm quantifies differences in the empiricalcumulative distribution functions of moving windows...

Background: The structure and function of fire-prone ecosystems are influenced by many interacting processes that develop over varying time scales. Fire creates both instantaneous and long-term changes in vegetation (defined as live, dead, and decomposing plant material) through combustion, heat transfer to living tissues, and subsequent patterns of recovery. While fuel available for combustion may be relative to the amount of vegetation, it is equally instructive to evaluate how the physical structure and other characteristics of vegetation influence fire dynamics, and how these interactio...