Chlorophyll fluorescence has developed into a well-established noninvasive technique to study photosynthesis and by extension, the physiology of plants and algae. The versatility of the fluorescence analysis has been improved significantly due to advancements in the technology of light sources, detectors, and data handling. This allowed the development of an instrumention that is effective, easy to handle, and affordable. Several of these techniques rely on point measurements. However, the response of plants to environmental stresses is heterogeneous, both spatially and temporally. Beside the nonimaging systems, low- and high-resolution imaging systems have been developed and are in use as real-time, multi-channel fluorometers to investigate heterogeneous patterns of photosynthetic performance of leaves and algae. This review will revise in several paragraphs the current status of chlorophyll fluorescence imaging, in exploring photosynthetic features to evaluate the physiological response of plant organisms in different domains. In the conclusion paragraph, an attempt will be made to answer the question posed in the title., R. Valcke., and Obsahuje bibliografické odkazy
Thirty years after the return of grey wolves (Canis lupus) to the French Alps, the number of livestock losses is on the rise despite livestock guarding dogs (LGDs) being widely used. Their relevance is, therefore, questioned by some sheep owner associations. To date, no study has investigated how LGDs interact with wolves in pastures. We present the results of a 6-year study totalling 3,300 hours of direct night-time observations to record the nature, frequency and outcomes of LGD-wolf interactions in the southern French Alps. We recorded 476 wolf events in the presence of LGDs, including 175 interactions, 66% of which were agonistic. Most (65%) of the interactions occurred at a distance > 100 m from the flock and on average involved more LGDs than wolves. In the presence of LGDs, wolves approached the flocks 134 times resulting in no attack (65%), attacks with no sheep victim (24.6%), or attacks with ≥ 1 sheep victim (10.4%). Our results suggest that LGD-wolf interactions are complex and do not simply occur in the immediate vicinity of the flock. We recommend using groups > 6 LGDs and reinforcing the presence of LGDs in a wider radius around the flock to limit the presence of isolated groups of sheep and to improve protection against wolf attacks.