Effects of timber harvest on epigeous fungal fruiting patterns and community structure in a northern hardwood ecosystem

Epigeous fungal fruiting has important impacts on fungal reproduction and ecosystem function. Forest disturbances, such as timber harvest, impact moisture, host availability, and substrate availability, which in turn may drive changes in fungal fruiting patterns and community structure. We surveyed mushrooms in 0.4-ha patch cuts (18 months post-harvest) and adjacent intact hardwood forest in northern New Hampshire, USA, to document the effects of timber harvest on summer fruiting richness, biomass, diversity, and community structure of ectomycorrhizal, parasitic, and saprobic mushroom taxa. Fungal fruiting richness, diversity, and community heterogeneity were greater in intact forests than patch cuts. Among functional groups, ectomycorrhizal fruiting richness, diversity, and biomass were greater in unharvested areas than in the patch cuts, but parasitic and saprobic fruiting did not differ statistically between the two forest conditions. Our findings suggest that timber harvest simplifies fungal fruiting communities shortly after harvest, in particular triggering declines in ectomycorrhizal taxa which are important symbionts facilitating tree establishment and regeneration. Multi-aged silvicultural practices that maintain mature forest conditions adjacent to and throughout harvested areas through deliberate retention of overstory trees and downed woody material may promote fungal fruiting diversity in regenerating stands.

Timber Exploitation in Colonial Brazil: A Historical Perspective of the Atlantic Forest

Timber was an important resource for the construction of colonial Brazil, although pertinent information is limited. We used the available archival material and an interdisciplinary methodology, spanning historical, botanical and ethnobotanical methods, to illuminate the exploitation of native timber during the colonial period and its relevance for the contemporary conservation status of the Atlantic Forest. Central to our methodology was the development of a standardized protocol focusing on folk names for timber trees, which permitted us to relate historical records and ecological data. Even though historical information is scarce, scattered, and sometimes contradictory, we could demonstrate the past prestige of timber as well as the harvest impact on local forests. We conclude that the extensive exploitation of the Atlantic Forest's timber resources throughout the colonial period contributed to the current state of vegetation, where many of the species abundant in the past are now rare and threatened.

Fluctuations of Production and Quality of Bananas Under Marginal Tropical Climate

The knowledge of the inter-seasonal fluctuations in characteristics of fruit quality and production is important for management of plants, prediction of yield and marketing strategies. This study aims to evaluate how the climatic conditions prevailing in the month of harvest impact bunch mass and variability of the size and color of the banana fruit ‘Nanica’ and ‘Prata’ cultivated under marginal tropical climate. The experiments were carried in Registro, Ribeira Valley region, São Paulo, Brazil, in a completely randomized design with 24 treatments (months of bunch harvest) and ten replications, for each cultivar. Cyclic seasonal fluctuations in production were found in for the two cultivars, with the lowest bunch mass (BM), fruit size consistently recorded between July and February associated with lower global solar radiation (Rad) and temperature (T) of the harvest month, but not precipitation (Ppt). The extension of monthly fluctuations in BM were similar to ‘Prata’ (18.95±3.31 kg) and ‘Nanica’ (29.51±4.69 kg). Independent of the harvest month, there was a trend of greater variability for fruit length (FL) and lower for fruit diameter (FD) between fruits of the different positions in the bunch. The correlations between Rad or T of harvest month with BM, FL, FD and SL were all positive. For both cultivars, the shelf life (SL) was longer for fruits of the last hand. There were also positive correlations between Rad or T with SL. The decrease of peel color characteristics of the ‘Nanica’ fruit was associated with cold fronts from autumn to spring and chilling injury, with higher intensity in the last hand.

Electrostatic MEMS Vibration Energy Harvesters inside of Tire Treads

An electret electrostatic MEMS vibration energy harvester for tire sensors mounted inside of the tire tread is reported. The device was designed so as to linearly change an electrostatic capacitance between the corrugated electret and output electrode according to the displacement of the proof mass. The electromechanical linearity was effective at reducing the power loss. The output power reached 495 μW under sinusoidal vibration despite the footprint size being as small as 1 cm2. Under impact vibration inside of the tire tread, the output power reached 60 μW at a traveling speed of 60 km/h. It was revealed that a higher mechanical resonance frequency of the harvester adjusted within the frequency band of a low-power spectral density of impact vibration acceleration was effective for high efficiency harvest impact vibration energy.

Effects of variable canopy retention harvest on epixylic bryophytes in boreal black spruce – feathermoss forests1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems.

Modification of forest attributes and structural components like downed wood (DW) during forest harvest can lead to local species loss. Epixylic bryophytes have been proposed as good indicators of such changes. Unharvested control, variable canopy retention, and single pass harvest represent a gradient in forest harvest impact and can be used to test the response of epixylic bryophytes to different levels of environmental change. The objective of this study was to see if variable canopy retention attenuates environmental change associated with harvesting, consequently maintaining an epixylic community more similar to unharvested stands than single pass harvesting. Environmental conditions and DW characteristics were sampled on 225 DW pieces distributed in 45 permanent plots. Results showed that treatment affected epixylic richness through its impact on canopy openness and DW diameter and decomposition class. Fewer species were found in more open habitats and more species were found on bigger and more decomposed DW. Most epixylic species were more commonly found on the forest floor than on the DW. In conclusion, variable canopy retention harvest offered microclimatic conditions and DW availability and quality more suitable for epixylic species than single pass harvest, which was less suitable for epixylic species.