Search results for "old-growth forest"

INVESTIGATION ON OLD-GROWTH FORESTS OF SICILY: PRELIMINARY RESULTS

2014

Old-growth forests are natural forests that have developed over a long period of time, without experiencing severe, stand-replacing disturbance a fire, windstorm, or logging. According to UNEP/CBD/SBSTTA definition, an old-growth forest is a primary or a secondary forest which has achieved an age at which structure and species normally associated with old primary forests of that type have sufficiently accumulated to act as a forest ecosystem distinct from any younger age class. In a thematic contribution to the National Biodiversity Strategy, the authors report the following definition of Italian old-growth forests: Forest in which human disturbance is absent or negligible, and in which nat…

Priority areas for the conservation of Atlantic forest large mammals

2009

Large mammal faunas in tropical forest landscapes are widely affected by habitat fragmentation and hunting, yet the environmental determinants of their patterns of abundance remain poorly understood at large spatial scales. We analysed population abundance and biomass of 31 species of medium to large-bodied mammal species at 38 Atlantic forest sites (including three islands, 26 forest fragments and six continuous forest sites) as related to forest type, level of hunting pressure and forest fragment size using ANCOVAs. We also derived a novel measure of mammal conservation importance for each site based on a "Mammalian Conservation Priority index" (MPi) which incorporates information on spec…

Carbon stock increases up to old growth forest along a secondary succession in Mediterranean island ecosystems.

2019

The occurrence of old-growth forests is quite limited in Mediterranean islands, which have been subject to particularly pronounced human impacts. Little is known about the carbon stocks of such peculiar ecosystems compared with different stages of secondary succession. We investigated the carbon variation in aboveground woody biomass, in litter and soil, and the nitrogen variation in litter and soil, in a 100 years long secondary succession in Mediterranean ecosystems. A vineyard, three stages of plant succession (high maquis, maquis-forest, and forest-maquis), and an old growth forest were compared. Soil samples at two soil depths (0-15 and 15-30 cm), and two litter types, relatively undec…

Fire Responses to the 2010 and 2015/2016 Amazonian Droughts

2019

Extreme droughts in Amazonia cause anomalous increase in fire occurrence, disrupting the stability of environmental, social and economic systems. Thus, understanding how droughts affect fire patterns in this region is essential for anticipating and planning actions for remediation of possible impacts. Focused on the Brazilian Amazon biome, we investigated fire responses to the 2010 and 2015/2016 Amazonian droughts using a remote sensing data. Our results revealed that the 2015/2016 drought surpassed the 2010 drought in intensity and extent. During the 2010 drought, we found a maximum area of 846,800 km2 (24% of the Brazilian Amazon biome) with significant (p<0.05) rainfall decrease in the f…

More wood but less biodiversity in forests in Finland: a historical evaluation

2022

National forest inventories (NFI) in Finland provide empirical evidence for a marked increase in tree growth, total forest area, and total timber volume over the past century. Meanwhile, the assessments of threatened forest species and habitats indicate continuous degradation of biodiversity in Finnish forests. To shed light on this seeming paradox, we summarized the temporal patterns of forest characteristics (indicators) that have major influence on biodiversity, comparing the structure of current Finnish forests with natural and historical references. Using a variety of data sources, we estimated the proportion of area of old-growth forest and of deciduous-dominated forests, the density …

Tree age‐dependent changes among epiphytic bryophyte communities in Mediterranean environments. A case study from Sicily (Italy)

2010

Abstract The epiphytic bryophytes inhabiting trees of different size/age in a Quercus ilex wood from Madonie Mountains (northern Sicily, Italy) were studied with the purpose of describing the changes that take place in the bryophyte stratum during the tree lifespan. Results indicate an increase of bryophyte cover combined with a progressive decrease of epiphytic lichens and the existence of an active process of species and community substitution. The way these processes take place corresponds to a succession sequence, which is characterised by a high number of pioneer species on the youngest trees and a sharp decline of species number on middle‐aged and old trees due to the great spread of …

Conservation value of forest plantations for bird communities in western Kenya

2008

Tree plantations of native and exotic species are frequently used to compensate for forest loss in the tropics. However, these plantations may support lower species diversity and different communities than natural forest. We therefore investigated bird communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. We compared birds differing in habitat specialisation, i.e. forest specialists, generalists, and visitors. We recorded significant differences in mean species richness and number of individuals among the different forest types. Stands of natural forest and plantations of indigenous tree species comprised more sp…

High seedling recruitment of indigenous tree species in forest plantations in Kakamega Forest, western Kenya

2009

Tree plantations are often used to compensate for the destruction and conversion of natural forests in the tropics. An important question is whether these plantations allow for the regeneration of indigenous tree species and are expected to transform into more natural forests in the future. To evaluate the potential of differently managed forest types for seedling recruitment of indigenous tree species we studied structural characteristics as well as tree and seedling communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. Forest types differed considerably in structural characteristics and tree composition with st…

Corrigendum: Fire Responses to the 2010 and 2015/2016 Amazonian Droughts

2019

Structural variables drive the distribution of the sensitive lichen Lobaria pulmonaria in Mediterranean old-growth forests

2015

a b s t r a c t We tested the hypothesis that structural variables related to old-growth features affect the distribution of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied. The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based solely on structural features is not sufficient to predict the presence of this species, which therefore proves to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area, and to availability of deadwood, confirmi…