Search results for "Bal"

Climate signal age effects in boreal tree-rings: Lessons to be learned for paleoclimatic reconstructions

2016

Abstract Age-related alternation in the sensitivity of tree-ring width (TRW) to climate variability has been reported for different forest species and environments. The resulting growth-climate response patterns are, however, often inconsistent and similar assessments using maximum latewood density (MXD) are still missing. Here, we analyze climate signal age effects (CSAE, age-related changes in the climate sensitivity of tree growth) in a newly aggregated network of 692 Pinus sylvestris L. TRW and MXD series from northern Fennoscandia. Although summer temperature sensitivity of TRW ( r All  = 0.48) ranges below that of MXD ( r All  = 0.76), it declines for both parameters as cambial age in…

The invasive Asparagopsis taxiformis hosts a low diverse and less trophic structured molluscan assemblage compared with the native Ericaria brachycar…

2021

Abstract Invasive seaweeds threaten biodiversity and socio-economics values of worldwide marine ecosystems. Understanding to what extent invasive seaweeds can modify local biodiversity is one of the main priorities in conservation ecology. We compared the molluscan assemblage of the invasive Asparagopsis taxiformis with that of the native Ericaria brachycarpa and explore if variation in the molluscan assemblage diversity was related to the substrate attributes (biomass, and thallus, canopy, and interstitial volumes) of the algae. Results showed that A. taxiformis harboured lower diversity and trophic structure of the molluscan assemblage compared to E. brachycarpa. Biomass was the variable …

Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies.

2012

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.

2018

Habitat associations drive species vulnerability to climate change in boreal forests

2016

Species climate change vulnerability, their predisposition to be adversely affected, has been assessed for a limited portion of biodiversity. Our knowledge of climate change impacts is often based only on exposure, the magnitude of climatic variation in the area occupied by the species, even if species sensitivity, the species ability to tolerate climatic variations determined by traits, plays a key role in determining vulnerability. We analyse the role of species’ habitat associations, a proxy for sensitivity, in explaining vulnerability for two poorly-known but species-rich taxa in boreal forest, saproxylic beetles and fungi, using three IPCC emissions scenarios. Towards the end of the 21…

Environment-sensitivity functions for gross primary productivity in light use efficiency models

2022

International audience; The sensitivity of photosynthesis to environmental changes is essential for understanding carbon cycle responses to global climate change and for the development of modeling approaches that explains its spatial and temporal variability. We collected a large variety of published sensitivity functions of gross primary productivity (GPP) to different forcing variables to assess the response of GPP to environmental factors. These include the responses of GPP to temperature; vapor pressure deficit, some of which include the response to atmospheric CO2 concentrations; soil water availability (W); light intensity; and cloudiness. These functions were combined in a full fact…

Land cover and its transformation in the backward trajectory footprint region of the Amazon Tall Tower Observatory

2019

Abstract. The Amazon rain forest experiences the combined pressures from human-made deforestation and progressing climate change, causing severe and potentially disruptive perturbations of the ecosystem's integrity and stability. To intensify research on critical aspects of Amazonian biosphere–atmosphere exchange, the Amazon Tall Tower Observatory (ATTO) has been established in the central Amazon Basin. Here we present a multi-year analysis of backward trajectories to derive an effective footprint region of the observatory, which spans large parts of the particularly vulnerable eastern basin. Further, we characterize geospatial properties of the footprint regions, such as climatic condition…

Alder pollen in Finland ripens after a short exposure to warm days in early spring, showing biennial variation in the onset of pollen ripening

2017

Abstract We developed a temperature sum model to predict the daily pollen release of alder, based on pollen data collected with pollen traps at seven locations in Finland over the years 2000–2014. We estimated the model parameters by minimizing the sum of squared errors (SSE) of the model, with weights that put more weight on binary recognition of daily presence or absence of pollen. The model results suggest that alder pollen ripens after a couple of warm days in February, while the whole pollen release period typically takes up to 4 weeks. We tested the model residuals against air humidity, precipitation and wind speed, but adding these meteorological features did not improve the model pr…

Coping with Difficult Weather and Snow Conditions : Reindeer herders’ views on climate change impacts and coping strategies

2016

Winter is a critical season for reindeer herding, with the amount and quality of snow being among the most important factors determining the condition of reindeer and the annual success of the livelihood. Our first aim was to model the future (2035–2064) snow conditions in northern Finland, especially the quantities related to ground ice and/or ice layers within the snow pack, exceptionally deep snow and late snow melt. Secondly, we studied the strategies by which herders cope with the impacts of difficult weather and snow conditions on herding by interviewing 21 herders. SNOWPACK simulations indicate that snow cover formation will be delayed by an average of 19 days and snow will melt 16 d…

Social process of adaptation to environmental changes: How eastern african societies intervene between crops and climate

2014

Abstract Studies on climate change can only be conducted on a long time scale, and observing how societies adapt their sowing practices to climate variability is challenging and costly. As an alternative, a space and time substitution design was used, changes in space corresponding to that induced in time by environmental change. On the eastern slope of Mount Kenya, the Tharaka community, originating from the lowlands (750 m), moved up to the midlands (950 m) with their lowland-adapted resources, whereas the Mwimbi, originating from wetter upland (1100 m), moved down to the midlands with their highland-adapted genetic resources. A weather station was installed at 950 and 1100 m, and a logis…