Search results for "FORESTS"

Diversidad liquénica asociada a fenómenos post-incendio en los alcornocales valenciano-castellonenses.

2001

FOS, S., CALATAYUD, A. & BARRENO, E. 2001. Lichen diversity associated with post-fire colonization in the Valenciano-castellonense cork-oak forests. Bot. Complutensis 25: 103113. 103 Simón Fos et al. Diversidad liquénica asociada a fenómenos post-incendio... The post-fire colonization of the burned barks of cork-oaks (Quercus suber L.) by epiphytic lichens affected by fire episodes has been studied in different areas of the Valenciano-castellonense cork-oak forests (Asplenio onopteridis-Querco suberis sigmetum). These forests, which have been affected by fires of different intensity, are located in Espadán and Calderona mountains and in the Desierto de Las Palmas and differ with respect…

Lauksaimnieka mežkopība

1929

Démarche statistique pour la sélection des indicateurs par Random Forests pour la surveillance de la qualité des sols

2013

The volume of data, and the large number of biological variables to be tested (one hundred), require analytical techniques, such asRandom Forests, which can overcome the problem of multi-colinearity for the selection of indicators, sensitive to various factors.Random Forests methodology is appropriate for the selection of the most discriminant variables. So, we searched for the best wayto select them, by bringing together all biological variables, representing the Microflora and Fauna. This approach focuses on impactindicators from the Bio2 program, indicators of flora and indicators of accumulation (snails) were not included.This work has been implemented on the three factors of discrimina…

Simplification, not “tropicalization”, of temperate marine ecosystems under ocean warming and acidification

2021

Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems…

Syntaxonomical analysis of the beech forests from Sicily

1999

The results of a phytosociological investigation on the beech forests occurring in Sicily are given. On the basis of literature and unpublished data, four well differentiated associations have been identified and classified within the Doronico-Fagion, alliance of Querco-Fagetea. All the surveyed woodlands are localized in the mountain belt of North and North-Eastern Sicily. The associations have been examined from the floristical, ecological, chorological and nomenclatural point of view. Besides, a numerical analysis applied to the phytosociological relevés emphasizes the differences among the associations.

Impact of hydrologically driven hillslope erosion and landslide occurrence on soil organic carbon dynamics in tropical watersheds

2016

The dynamics of soil organic carbon (SOC) in tropical forests play an important role in the global carbon (C) cycle. Past attempts to quantify the net C exchange with the atmosphere in regional and global budgets do not systematically account for dynamic feedbacks among linked hydrological, geomorphological, and biogeochemical processes, which control the fate of SOC. Here we quantify effects of geomorphic perturbations on SOC oxidation and accumulation in two adjacent wet tropical forest watersheds underlain by contrasting lithology (volcaniclastic rock and quartz diorite) in the Luquillo Critical Zone Observatory. This study uses the spatially-explicit and physically-based model of SOC dy…

Contrasting Effects of Chronic Anthropogenic Disturbance on Activity and Species Richness of Insectivorous Bats in Neotropical Dry Forest

2022

For prioritizing conservation actions, it is vital to understand how ecologically diverse species respond to environmental change caused by human activity. This is particularly necessary considering that chronic human disturbance is a threat to biodiversity worldwide. Depending on how species tolerate and adapt to such disturbance, ecological integrity and ecosystem services will be more or less affected. Bats are a species-rich and functionally diverse group, with important roles in ecosystems, and are therefore recognized as a good model group for assessing the impact of environmental change. Their populations have decreased in several regions, especially in the tropics, and are threatene…

Observations and snow model simulations of winter energy balance terms within and between different coniferous forests in Southern Boreal Finland

2015

Variation of canopy properties between different forest types is seldom taken into account in hydrological and climate models, and consideration of variation inside a forest is normally omitted. In this work, three data sets on near surface energy balance terms (incoming shortwave and longwave radiation; air and snow–soil interface temperatures) were collected in the southern boreal coniferous zone in Finland during three winters below different types of forest canopies. The aim was to evaluate the ability of a snow mass and energy balance model with a canopy module to reproduce the observed differences in below-canopy incoming radiations and snow–soil interface temperature. Clear differenc…

Hyperspectral UAV-Imagery and photogrammetric canopy height model in estimating forest stand variables

2017

Remote sensing using unmanned aerial vehicle (UAV) -borne sensors is currently a highly interesting approach for the estimation of forest characteristics. 3D remote sensing data from airborne laser scanning or digital stereo photogrammetry enable highly accurate estimation of forest variables related to the volume of growing stock and dimension of the trees, whereas recognition of tree species dominance and proportion of different tree species has been a major complication in remote sensing-based estimation of stand variables. In this study the use of UAV-borne hyperspectral imagery was examined in combination with a high-resolution photogrammetric canopy height model in estimating forest v…

Sensitivity of L-band vegetation optical depth to carbon stocks in tropical forests: a comparison to higher frequencies and optical indices

2019

Supplementary data to this article can be found online at https://doi.org/10.1016/j.rse.2019.111303. Monitoring vegetation carbon in tropical regions is essential to the global carbon assessment and to evaluate the actions oriented to the reduction of forest degradation. Mainly, satellite optical vegetation indices and LiDAR data have been used to this purpose. These two techniques are limited by cloud cover and are sensitive only to the top of vegetation. In addition, the vegetation attenuation to the soil microwave emission, represented by the vegetation optical depth (VOD), has been applied for biomass estimation using frequencies ranging from 4 to 30¿GHz (C- to K-bands). Atmosphere is t…