Search results for "Ecophysiology"

STUDIES ON SOME ECOPHYSIOLOGICAL, METABOLIC AND AGRONOMIC ASPECTS OF TREE NUTS

Thermal adaptation and physiological responses to environmental stress in tunicates

2017

Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected a…

A bioenergetics framework for integrating the effects of multiple stressors: Opening a 'black box' in climate change research

2015

Climate change is already impacting marine ecosystems across a range of scales, from individual physiology, to changes in species interactions and community structure, and ultimately to patterns in geographic distribution. Predicting how marine ecosystems will respond to environmental change is a signifi cant challenge because vulnerability to climatic and non-climatic stressors is highly variable, and depends on an organism’s functional traits, tolerance to stressors, and the environment in which it lives. We present a mechanistic approach based on biophysical and dynamic energy budget models that integrates the cumulative effects of multiple environmental stressors (temperature and food) …

The impact of climate change on Mediterranean intertidal communities: losses in coastal ecosystem integrity and services

2014

As has been shown for other ecosystems, the ecological and socio-economic impacts of climate change on Mediterranean intertidal habitats are highly variable in space and time. We conducted field and laboratory measurements of cellular, ecophysiological and behavioural responses of selected intertidal invertebrates (mussels, gastropods and sponges) and completed a literature review to determine what is known of socioeconomic consequences of these biological changes. Results suggest significant gaps in our knowledge that may impede a complete understanding of likely impacts (physical, biological, and socioeconomic) and that sufficient data for such an analysis is available only for mussels. A…

Fish-seastar facilitation leads to algal forest restoration on protected rocky reefs

2015

AbstractAlthough protected areas can lead to recovery of overharvested species, it is much less clear whether the return of certain predator species or a diversity of predator species can lead to re-establishment of important top-down forces that regulate whole ecosystems. Here we report that the algal recovery in a Mediterranean Marine Protected Area did not derive from the increase in the traditional strong predators, but rather from the establishment of a previously unknown interaction between the thermophilic fish Thalassoma pavo and the seastar Marthasterias glacialis. The interaction resulted in elevated predation rates on sea urchins responsible for algal overgrazing. Manipulative ex…

Long-Term Coexistence of Rotifer Cryptic Species

2011

Despite their high morphological similarity, cryptic species often coexist in aquatic habitats presenting a challenge in the framework of niche differentiation theory and coexistence mechanisms. Here we use a rotifer species complex inhabiting highly unpredictable and fluctuating salt lakes to gain insights into the mechanisms involved in stable coexistence in cryptic species. We combined molecular barcoding surveys of planktonic populations and paleogenetic analysis of diapausing eggs to reconstruct the current and historical coexistence dynamics of two highly morphologically similar rotifer species, B. plicatilis and B. manjavacas. In addition, we carried out laboratory experiments using …

Adaptive radiation along a thermal gradient: preliminary results of habitat use and respiration rate divergence among whitefish morphs.

2014

Adaptive radiation is considered an important mechanism for the development of new species, but very little is known about the role of thermal adaptation during this process. Such adaptation should be especially important in poikilothermic animals that are often subjected to pronounced seasonal temperature variation that directly affects metabolic function. We conducted a preliminary study of individual lifetime thermal habitat use and respiration rates of four whitefish (Coregonus lavaretus (L.)) morphs (two pelagic, one littoral and one profundal) using stable carbon and oxygen isotope values of otolith carbonate. These morphs, two of which utilized pelagic habitats, one littoral and one …

Biological Flora of the British Isles: Ambrosia artemisiifolia

2015

This account presents information on all aspects of the biology of Ambrosia artemisiifolia L. (Common ragweed) that are relevant to understanding its ecology. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, and history, conservation, impacts and management. Ambrosia artemisiifolia is a monoecious, wind-pollinated, annual herb native to North America whose height varies from 10 cm to 2.5 m, according to environmental conditions. It has erect, branched stems …

Decreasing Phanerozoic extinction intensity as a consequence of Earth surface oxygenation and metazoan ecophysiology

2021

The decline in background extinction rates of marine animals through geologic time is an established but unexplained feature of the Phanerozoic fossil record. There is also growing consensus that the ocean and atmosphere did not become oxygenated to near-modern levels until the mid-Paleozoic, coinciding with the onset of generally lower extinction rates. Physiological theory provides us with a possible causal link between these two observations-predicting that the synergistic impacts of oxygen and temperature on aerobic respiration would have made marine animals more vulnerable to ocean warming events during periods of limited surface oxygenation. Here, we evaluate the hypothesis that chang…

Challenges and opportunities for innovative research on legume nutrition and stress adaptation: an ecophysiologist’s and phenotyping point of view

2019

International audience; Agroecology needs to reconcile agronomy and ecology, preserving and valorizing plant and microbe biodiversity. Legumes have merits for agroecology considering their ecological services. They constitute a protein source and their production relocation give merits for feed and food. However, they are still under represented due to both biotic and abiotic constraints. Research need to increase their profitability through higher and more stable yield and protein content, and new uses in a fluctuating environment [2]. Mechanisms which control nutrient use efficiency have to be highlighted i) considering nutrient acquisition, storage, remobilization [3] ii) under various c…