Search results for " Past"
showing 10 items of 316 documents
Dead wood gathering among Neanderthal groups: Charcoal evidence from Abric del Pastor and El Salt (Eastern Iberia)
2017
International audience; We present here a new approach combining the microscopic characterization of fungal decay features and the fragmentation degree of the charcoal remains from Middle Palaeolithic combustion structures: features H4 and H11 from Abric del Pastor, unit IV (>75 ka BP) and features H50 and H57 from El Salt, unit Xb (ca. 52 ka BP), Eastern Iberia. The observation of wood degradation patterns that occurred prior to charring followed by their quantitative analysis according to previous experimental studies revealed differences between the alteration degrees of the firewood used in the hearths, highlighting the existence of firewood acquisition criteria based on dead wood gathe…
Ectomycorrhizal fungi in wood-pastures : Communities are determined by trees and soil properties, not by grazing
2019
Traditional rural biotopes such as wood-pastures are species-rich environments that have been created by low-intensity agriculture. Their amount has decreased dramatically during the 20th century in whole Europe due to the intensification of agriculture. Wood-pastures host some fungal species that prefer warm areas and are adapted to semi-open conditions, but still very little is known about fungi in these habitats. We studied how management, historical land-use intensity, present grazing intensity, time since abandonment, and stand conditions affect the species richness and community composition of ectomycorrhizal fungi. We surveyed fruit bodies on three 10 m × 10 m study plots in 36 sites…
Grazing and abandonment determine different tree dynamics in wood-pastures
2016
Wood-pastures are threatened biotopes in which trees and livestock grazing maintain high conservation values. However, browsing may threaten tree regeneration, whereas abandonment leads to tree encroachment. We studied the regeneration of trees in a grazed and abandoned boreal wood-pastures. In grazed sites, the density of young spruces (Picea abies) was high, while the density of young birches (Betula spp.) was very low. Sprucification can be prevented only by removing spruces. The number of young birches and pines (Pinus sylvestris) was correlated with the number of junipers (Juniperus communis), probably because thorny junipers protect palatable seedlings from browsing. In abandoned site…
Carbon storage of Mediterranean grasslands
2016
Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses (Ampelodesmos mauritanicus and Hyparrhenia hirta) and an invasive alien grass (Pennisetum setaceum). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands,…
Gene regulation in parthenocarpic tomato fruit.
2009
Parthenocarpy is potentially a desirable trait for many commercially grown fruits if undesirable changes to structure, flavour, or nutrition can be avoided. Parthenocarpic transgenic tomato plants (cv MicroTom) were obtained by the regulation of genes for auxin synthesis (iaaM) or responsiveness (rolB) driven by DefH9 or the INNER NO OUTER (INO) promoter from Arabidopsis thaliana. Fruits at a breaker stage were analysed at a transcriptomic and metabolomic level using microarrays, real-time reverse transcription-polymerase chain reaction (RT-PCR) and a Pegasus III TOF (time of flight) mass spectrometer. Although differences were observed in the shape of fully ripe fruits, no clear correlatio…
Reviewing research priorities in weed ecology, evolution and management: a horizon scan.
2018
Weedy plants pose a major threat to food security, biodiversity, ecosystem services and consequently to human health and wellbeing. However, many currently used weed management approaches are increasingly unsustainable. To address this knowledge and practice gap, in June 2014, 35 weed and invasion ecologists, weed scientists, evolutionary biologists and social scientists convened a workshop to explore current and future perspectives and approaches in weed ecology and management. A horizon scanning exercise ranked a list of 124 pre-submitted questions to identify a priority list of 30 questions. These questions are discussed under seven themed headings that represent areas for renewed and em…
Land-use and climate related drivers of change in the reindeer management system in Finland: geography of perceptions
2021
Drivers of change in the reindeer management system are rather well-known. But when developing the gover-nance to support the traditional livelihoods, it is crucial to understand also practitioner perceptions. Systematic research on these is lacking. We analyzed the land-use and climate related drivers within the reindeer man-agement area (RMA) in Finland, and, using a perception geography approach, studied the herder perceptions towards these. We conducted an on-site questionnaire survey with herders from 51 herding districts. Factors directly affecting the welfare of reindeer were perceived as crucial by herders, for example basal icing affecting the forage availability, and land-use rela…
A multi-site study to classify semi-natural grassland types
2009
International audience; Calibration and validation of simulation models describing herbage growth or feed quality of seminatural grasslands is a complex task for agronomists without investing effort into botanical surveys. To facilitate such modelling efforts, a limited number of grassland types were identified using a functional classification of species. These grassland types were characterized by three descriptors required to model herbage growth or feed quality: the abundance-weighted mean leaf dry matter content across grass species, the relative abundance of grasses, and an estimate of species richness. We conducted a multi-site analysis over 749 grasslands from eight temperate region…
The role of novel forest ecosystems in the conservation of wood-inhabiting fungi in boreal broadleaved forests
2016
The increasing human impact on the earth’s biosphere is inflicting changes at all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emergence of novel habitats. In boreal zone, intensive forest management has negatively impacted a multitude of deadwood-associated species. This is especially alarming given the important role wood-inhabiting fungi have in the natural decay processes. In the boreal zone, natural broad-leaved-dominated, herb-rich forests are threatened habitats which have high wood-inhabiting fungal species richness. Fungal diversity in other broadleaved forest habitat types is po…
Grazing and soil pH are biodiversity drivers of vascular plants and bryophytes in boreal wood-pastures
2016
Abstract Wood-pastures have been formed by traditional low-intensity livestock grazing in wooded areas. They host high biodiversity values that are now threatened by both management abandonment (ceased grazing) and agricultural intensification, and therefore these habitats are of conservation interest in Europe. In order to explore the effects of grazing on the biodiversity of boreal wood-pastures, we studied the communities of vascular plants and bryophytes in 24 currently grazed and 24 abandoned sites. In addition to the current management situation, we studied the effects of soil pH and moisture, tree density, historical land-use intensity, time since abandonment (in abandoned sites) and…