Search results for "ELEVATION"

Topographic descriptors and thermal inversions amid the plateaus and mountains of the Jura (France)

2018

Sixteen temperature measurement sites under forest cover are distributed across the plateaus and mountains of the Jura (France). They are composed of pairs of stations located, one at the bottom of a topographic trough, the other at least 50 m higher in altitude. Three descriptors (station elevation, altitudinal difference (amplitude) between the two stations of each site, and topographical context) are used to explain how the frequency, intensity, and duration of inversions are spatially structured. Depending on whether one considers: 1) tn (minimum temperature) or tx (maximum temperature), 2) frequency or intensity, the sign of the correlation values changes. This reflects the fact that n…

Dynamics of small-mammal communities along an elevational gradient

2019

Elevation is one of the most important natural gradients that is strongly shaping communities across relatively small areas. However, few studies have followed the temporal dynamics of elevational patterns, even in organisms for which population and community fluctuations have been extensively studied, such as rodents. Here we report the multiannual dynamics of small-mammal communities along an elevational gradient in the Southern Carpathians. During a 5-year survey, we conducted live-trapping in forested and shrubby habitats, at elevations between 820 and 2040 m. We used partial constrained multivariate analysis and mixed-effects models to test the effect of elevation, year, and their int…

Vulnerability of Norway spruce to climate change in mountain forests of the European Alps

2014

Mountain forests offer a range of socio-economic and ecological services, e.g. provid- ing wood harvest products, serving as hotspots of biodiversity and fulfilling protective functions. In the European Alps, where these environments are dominated by drought-sensitive Norway spruce, it has been questioned whether these services can be secured in the substantially warmer and drier climates predicted for the mid-to-late 21st century. Here, we compile a tree-ring width network of 500 spruce trees from the Northern Limestone Alps to assess growth reactions to drought events and evaluate the long-term impact of the recent temperature shift through ana - lyses along elevational transects. Our dat…

Fine‐grain beta diversity of Palaearctic grassland vegetation

2021

QUESTIONS: Which environmental factors influence fine-grain beta diversity of vegetation and do they vary among taxonomic groups? LOCATION: Palaearctic biogeographic realm. METHODS: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database, covering a wide range of different grassland and other open habitat types. We derived extensive environmental and structural information for these series. For each series and four taxonomic groups (vascular plants, bryophytes, lichens, all), we calculated the slope parameter (z-value) of the power law species–area relationship (SAR), as a beta diversity measure. We tested whe…

A millennium-long perspective on high-elevation pine recruitment in the Spanish central Pyrenees

2018

Long-term fluctuations in forest recruitment, at time scales well beyond the life-span of individual trees, can be related to climate changes. The underlying climatic drivers are, however, often understudied. Here, we present the recruitment history of a high-elevation mountain pine (Pinus uncinata Ram.) forest in the Spanish central Pyrenees throughout the last millennium. A total of 1108 ring-width series translated into a continuous chronology from 924 to 2014 CE, which allowed estimated germination dates of 470 trees to be compared against decadal-scale temperature variability. High recruitment intensity mainly coincided with relatively warm periods in the early 14th, 15th, 19th, and 2…

A bark beetle infestation predictive model based on satellite data in the frame of decision support system TANABBO

2020

The European spruce bark beetle Ips typographus L. causes significant economic losses in managed coniferous forests in Central and Northern Europe. New infestations either occur in previously undisturbed forest stands (i.e., spot initiation) or depend on proximity to previous years’ infestations (i.e., spot spreading). Early identification of newly infested trees over the forested landscape limits the effective control measures. Accurate forecasting of the spread of bark beetle infestation is crucial to plan efficient sanitation felling of infested trees and prevent further propagation of beetle-induced tree mortality. We created a predictive model of subsequent year spot initiation and spo…

2021

Maximum latewood density (MXD) measurements from long-lived Black pines (Pinus nigra spp. laricio) growing at the upper treeline in Corsica are one of the few archives to reconstruct southern European summer temperatures at annual resolution back into medieval times. Here, we present a compilation of five MXD chronologies from Corsican pines that contain high-to-low frequency variability between 1168 and 2016 CE and correlate significantly (p < 0.01) with the instrumental April–July and September–October mean temperatures from 1901 to 1980 CE (r = 0.52−0.64). The growth–climate correlations, however, dropped to −0.13 to 0.02 afterward, and scaling the MXD data resulted in a divergence of…

Dwarf shrub vegetation of rock ledges and clefts in the Pamir Alai Mountains (Middle Asia: Tajikistan)

2016

AbstractThe paper presents the results of phytosociological researches on rocky slope vegetation in Tajikistan with the aim to establish a comprehensive syntaxonomical classification system. Field studies were conducted in 2010-2014 in Pamir Alai ranges and Pamirian plateau. Nearly 500 relevés documenting rock and scree vegetation were made according to the Braun-Blanquet method. Numerical analyses of selected 58 relevés representing dwarf shrub vegetation on rock ledges made it possible to distinguish: Ephedro glaucae- Spiraeion baldschuanicae and Ephedrion regeliano-fedtschenkoi alliances, as well as Spiraeetum baldschuanicae, Rhamnetum coriaceae, Pentaphylloidetum parvifoliae and Pentaph…

Land Cover Trade-offs in Small Oceanic Islands: A Temporal Analysis of Pico Island, Azores

2017

Livestock production has been highly relevant in the Azores, boosted by European agricultural policies, increasing the demand for pasture and competing for space with other land uses. Therefore, it is important to understand the spatial evolution of pasture and related LULC trade-offs. This study describes a GIS-based LULC change detection approach to identify, map and assess pasture-related land use changes and respective trade-offs in Pico Island in the period between 1998 and 2013 (15 years). Pasture in 1998 occupied a total area of 17131 ha (about 39% of Pico Island surface), while in 2013 this same area was of 17621 ha (about 40% of Pico Island surface). During this period, about 16316…

Sweet taste of prosocial status signaling: When eating organic foods makes you happy and hopeful.

2018

As the current research suggests that there are links between prosocial acts and status signaling (including sustainable consumer choices), we empirically study (with three experiments) whether food consumers go green to be seen. First, we examine how activating a motive for status influences prosocial organic food preferences. Then, we examine how the social visibility of the choice (private vs. public) affects these preferences. We found that when consumers' desire for status was elicited, they preferred organic food products significantly over their nonorganic counterparts; making the choice situation visible created the same effect. Finally, we go beyond consumers' evaluative and behavi…