Search results for "MPT"

Assessing the role of megafauna in tropical forest ecosystems and biogeochemical cycles - the potential of vegetation models

2018

21 pages; International audience; Megafauna (terrestrial vertebrate herbivores > 5 kg) can have disproportionate direct and indirect effects on forest structure, function, and biogeochemical cycles. We reviewed the literature investigating these effects on tropical forest dynamics and biogeochemical cycles in relation to ecology, paleoecology, and vegetation modelling. We highlight the limitations of field‐based studies in evaluating the long‐term consequences of loss of megafauna. These limitations are due to inherent space‐time restrictions of field‐studies and a research focus on seed dispersal services provided by large animals. We further present evidence of a research gap concerning t…

2018

A unified vegetation index for quantifying the terrestrial biosphere

2021

[EN] Empirical vegetation indices derived from spectral reflectance data are widely used in remote sensing of the biosphere, as they represent robust proxies for canopy structure, leaf pigment content, and, subsequently, plant photosynthetic potential. Here, we generalize the broad family of commonly used vegetation indices by exploiting all higher-order relations between the spectral channels involved. This results in a higher sensitivity to vegetation biophysical and physiological parameters. The presented nonlinear generalization of the celebrated normalized difference vegetation index (NDVI) consistently improves accuracy in monitoring key parameters, such as leaf area index, gross prim…

Chlorophyll fluorescence emission spectrum inside a leaf

2008

International audience; Chlorophyll a fluorescence can be used as an early stress indicator. Fluorescence is also connected to photosynthesis so it can be proposed for global monitoring of vegetation status from a satellite platform. Nevertheless, the correct interpretation of fluorescence requires accurate physical models. The spectral shape of the leaf fluorescence free of any re-absorption effect plays a key role in the models and is difficult to measure. We present a vegetation fluorescence emission spectrum free of re-absorption based on a combination of measurements and modelling. The suggested spectrum takes into account the photosystem I and II spectra and their relative contributio…

Diet composition and biomass consumption of harbour seals in Telemark and Aust-Agder, Norwegian Skagerrak

2020

To explore ecosystem dynamics and functions it is vital to obtain knowledge on predator–prey relations. Harbour seals are piscivorous predators that can come into conflict with fisheries. Recently, as the Skagerrak and Kattegat population of harbour seals has increased, claims have emerged that seals are depleting coastal cod populations. The diet of harbour seals in Norwegian Skagerrak was investigated based on otolith identification from scats. The overall seal diet included 20 different fish species/groups. The most important prey (combined index Q i ) were haddock/pollack/saithe (32.7%), genus Trisopterus (Norway pout/poor cod/bib, 12.5%), plaice (12.4%) and herring (10.0%). Plaice also…

Consumer behaviour change through education for sustainable development: case of Latvia

2018

More sustainability and sustainable development are major challenges faced by society today. Consumer's choices and the use of products and services have important impacts on the environment; consequently, consumer behaviour is crucial. Education and pedagogics help select real sustainable living attitudes of students, their families and friends. This case study describes the mid-term results of a teaching assignment and survey in three Latvian higher education organisations which involve system thinking and students' action on consumer choices of household chemicals. The multilayer results provide insight into the consumption of these chemicals and show that one year after the assignment, …

Predators' consumption of unpalatable prey does not vary as a function of bitter taste perception

2020

Many prey species contain defensive chemicals that are described as tasting bitter. Bitter taste perception is, therefore, assumed to be important when predators are learning about prey defenses. However, it is not known how individuals differ in their response to bitter taste, and how this influences their foraging decisions. We conducted taste perception assays in which wild-caught great tits (Parus major) were given water with increasing concentrations of bitter-tasting chloroquine diphosphate until they showed an aversive response to bitter taste. This response threshold was found to vary considerably among individuals, ranging from chloroquine concentrations of 0.01 mmol/L to 8 mmol/L.…

Aquatic and Semiaquatic Heteroptera (Nepomorpha) from the Strei River Basin

2018

Abstract During a field campaign in the Strei River basin in August 2014, seven suitable habitats for aquatic and semi-aquatic true bugs were identified from the confluence of the Strei River with the Bărbat River down to the confluence with the Mureș River. Forty-eight individuals belonging to 15 species and nine families of aquatic and semi-aquatic true bugs were sampled. We mention two species considered rare in Romanian fauna: Hebrus montanus and Microvelia pygmaea. The statistic-mathematical analysis showed the similarity of the true bugs’ communities from habitats with similar conditions, as well as the relation of each species with particular habitat conditions, emphasizing the fact …

Translocation of meadow, heath and fen to the habitat garden : the first insights after 4 years of the experiment

2018

Landmarks in the historical development of twenty first century food processing technologies.

2017

International audience; Over a course of centuries, various food processing technologies have been explored and implemented to provide safe, fresher-tasting and nutritive food products. Among these technologies, application of emerging food processes (e.g., cold plasma, pressurized fluids, pulsed electric fields, ohmic heating, radiofrequency electric fields, ultrasonics and megasonics, high hydrostatic pressure, high pressure homogenization, hyperbaric storage, and negative pressure cavitation extraction) have attracted much attention in the past decades. This is because, compared to their conventional counterparts, novel food processes allow a significant reduction in the overall processi…