Search results for "Pose"
showing 10 items of 1189 documents
Gas Exchanges and Stem Water Potential Define Stress Thresholds for Efficient Irrigation Management in Olive (Olea europea L.)
2018
With climate change and decreased water supplies, interest in irrigation scheduling based on plant water status is increasing. Stem water potential (ΨSWP) thresholds for irrigation scheduling in olive have been proposed, however, a physiologically-based evaluation of their reliability is needed. A large dataset collected at variable environmental conditions, growing systems, and genotypes was used to characterize the relation between ΨSWP and gas exchanges for olive. Based on the effect of drought stress on the ecophysiological parameters monitored, we described three levels of stress: no stress (ΨSWP above about −2 MPa), where the high variability of stomatal conductance (gs) suggests a ti…
Influence des phosphates naturels et des mycorhizes à vésicules et à arbuscules sur la croissance et la nutrition minérale de Zizyphus mauritiana Lam…
1998
Rock phosphate and vesicular-arbuscular mycorrhiza effects on growth and mineral nutrition of Zizyphus mauritiana Lam. in an alkaline soil. The influence of vesicular-arbuscular mycorrhizae (VAM) and rock phosphate (RP) was studied on jujube (Zizyphus mauritiana Lam.), a multipurpose fruit tree in Sahelian agroforestry systems. Jujubes were inoculated or not by Clomus manihotis Howeler, Sieverding & Schenck in an alkaline sandy soil to which were added five levels of RP (12 % of P) : 0.00, 0.31, 0.62, 1.25 et 2.50 g P/kg of soil, equivalent to 0, 775, 1 550, 3 125 et 6 250 kg P ha -1 . The jujubes seedlings grew poorly without mycorrhizal colonization and without RP applications (figures 1a…
Characterizing the pigment composition of a variable warning signal of Parasemia plantaginis larvae
2010
Summary 1. Aposematic animals advertise their defences to predators via warning signals that often are bright colours combined with black patterns. Predation is assumed to select for large pattern elements and conspicuousness of warning signals because this enhances avoidance learning of predators. However, conspicuousness of the colour pattern can vary among individuals of aposematic species, suggesting that warning signal expression may be constrained by opposing selection pressures. If effective warning signals are costly to produce, variation in signal expression may be maintained via physiological trade-offs. To understand the costs of signalling that might underlay both physiological …
Effects of the filter-feeding benthic bivalve corbicula fluminea on plankton community and water quality in aquatic ecosystems: A mesocosm study
2021
The influence of filter-feeding bivalves on plankton communities, nutrients, and water quality in a given aquatic ecosystem is so profound that they can be considered ecosystem engineers. In a 70-day mesocosm experiment, we tested the hypothesis that Corbicula fluminea would change plankton community structure by reducing small zooplankton and large phytoplankton and improve water quality by reducing nutrients. We monitored levels of nitrogen and phosphorus, organic suspended solids (OSS), and light at the sediment surface. Within the plankton, phytoplankton biomass (as Chl a, >
Towards a tractable working hypothesis for deimatic displays
2016
How to Assess the Ecological Status of Highly Humic Lakes? Development of a New Method Based on Benthic Invertebrates
2021
Highly humic lakes are typical for the boreal zone. These unique ecosystems are characterised as relatively undisturbed habitats with brown water, high acidity, low nutrient content and lack of macrophytes. Current lake assessment methods are not appropriate for ecological assessment of highly humic lakes because of their unique properties and differing human pressures acting on these ecosystems. This study proposes a new approach suitable for the ecological status assessment of highly humic lakes impacted by hydrological modifications. Altogether, 52 macroinvertebrate samples from 15 raised bog lakes were used to develop the method. The studied lakes are located in the raised bogs at the c…
Intermittent Aeration in a Hybrid Moving Bed Biofilm Reactor for Carbon and Nutrient Biological Removal
2020
The paper presents an experimental study on a lab scale hybrid moving bed biofilm reactor with intermittent aeration. Specifically, a comparison between two different operating conditions was analyzed: continuous and intermittent aeration. Both continuous and intermittent aeration were monitored and compared in order to get the best operational conditions. The intermittent aeration campaign was sub-divided in three phases with different duration of alternation of aerobic and anoxic times and organic and nitrogen loading rates. The efficiency of N-removal improved by 70% during the intermittent aeration. The best condition was observed with 40 min of aeration and 20 min of no-aeration, an or…
On the Occurrence of Metadiaptomus chevreuxi (Calanoida, Diaptomidae, Paradiaptominae) in the Iberian Peninsula, With Notes on the Ecology and Distri…
2020
Temporary ponds are one of the most peculiar ecosystems in the world, being characterized by an extraordinarily rich crustacean fauna, with a high degree of endemism. Among them, diaptomid copepods are among the most biogeographically interesting taxa. However, the present knowledge on diaptomid distribution is still far from being exhaustive, even in the relatively well-studied western European countries. In this study, we report the first record of the diaptomid calanoid copepod Metadiaptomus chevreuxi for the Iberian Peninsula, where it was collected in five temporary ponds in Andalusia (Spain). The characteristics of the new sites are described, the literature dealing with the European …
Characteristics, Main Impacts, and Stewardship of Natural and Artificial Freshwater Environments: Consequences for Biodiversity Conservation
2020
International audience; In this overview (introductory article to a special issue including 14 papers), we consider all main types of natural and artificial inland freshwater habitas (fwh). For each type, we identify the main biodiversity patterns and ecological features, human impacts on the system and environmental issues, and discuss ways to use this information to improve stewardship. Examples of selected key biodiversity/ecological features (habitat type): narrow endemics, sensitive (groundwater and GDEs); crenobionts, LIHRes (springs); unidirectional flow, nutrient spiraling (streams); naturally turbid, floodplains, large-bodied species (large rivers); depth-variation in benthic commu…
Effects of local forest continuity on the diversity of fungi on standing dead pines
2018
Human-induced fragmentation affects forest continuity, i.e. availability of a suitable habitat for the target species over a time period. The dependence of wood-inhabiting fungi on landscape level continuity has been well demonstrated, but the importance of local continuity has remained controversial. In this study, we explored the effects of local forest continuity (microhabitat and stand level) on the diversity of wood-inhabiting fungi on standing dead trunks of Scots pine (Pinus sylvestris L.). We studied species richness and community composition of decomposers and Micarea lichens on 70 trunks in 14 forests in central Finland that differed in their state of continuity. We used dendrochr…