Fátlan vegetációtípusok azonosítása légi hiperspektrális távérzékelési módszerrel

Munkánk során egy szikes táj vegetációtípusainak osztályozását végeztük el, légi hiperspektrális adatok felhasználásával. A munka célja a hiperspektrális adatok alkalmazhatóságának vizsgálata volt e komplex társulásoknál, eltérő képosztályozási módszerek alkalmazásával. Vizsgálatunkban hagyományos osztályozó eljárások (Maximum Likelihood Classifier – MLC, Random Forest – RF és Support Vector Machine – SVM) eredményességét teszteltük 10 és 30 pixeles tanítóterületek felhasználásával. A mozaikolt hiperspektrális felvételen a zajszűrés és az információnyerés céljából MNF transzformációt alkalmaztunk. A légi hiperspektrális felvétel AISA EAGLE II szenzorral készült 1m terepi felbontásban. Társulástani besorolás és felszínborítás alapján összesen 20 vegetációosztályt alakítottunk ki. Az osztályokat további négy főbb élőhelykategóriába soroltuk: sztyeppék, nyílt szikes gyepek, szikes rétek, szikes és nem szikes mocsarak. Az SVM és az RF osztályozó eljárások, a pixelek számától függetlenül, majdnem minden vegetációosztálynál megbízhatóan működtek, nagy osztályozási pontosságot adtak. Az MLC bár nagy mintaszámnál nagy pontosságú osztályozást eredményezett, kis mintaszámnál számos osztály esetében alacsony megbízhatósággal működött. Az eredmények alapján elmondható, hogy a komplex fátlan táji környezetben a vegetáció osztályozásra az SVM megfelelő osztályozó lehet, mivel nagyobb pontosságot nyújt, mint az RF és az MLC. Az SVM bizonyult a legkevésbé érzékenynek a tanító területek mintáinak méretére, így alkalmas lehet azokban az esetekben, amikor néhány osztálynál az elérhető pixelek száma korlátozottan áll rendelkezésre

Frequency of diarrhoea-associated viruses in swine of various ages in Hungary

Enteric viral diseases of swine are one of the most frequent disorders causing huge economic losses in pork production. After the reappearance of an emerging enteropathogen, porcine epidemic diarrhoea virus (PEDV) in Hungary in 2016, an extensive survey was initiated in an attempt to identify diarrhoea-related porcine viruses, including adeno-, astro-, boca-, calici-, circo-, corona-, kobu-, rota- and Torque teno viruses. A total of 384 faecal samples collected during a twoyear period from diarrhoeic and asymptomatic pigs of various ages in 17 farms were screened by conventional and real-time PCR methods. Half of the samples contained at least one examined virus with the dominance of kobuvirus (55.1%) followed by bocaviruses (33.2%) and rotavirus groups A and C together (20.9%), while coronaviruses including PEDV were not found in this set of samples. Statistical analysis showed a highly significant difference (P < 0.0001) in the frequency of single infections compared to mixed ones with the exception of weaned pigs, in which group additionally most viruses were detected. The results of this study suggest that the complexity of this disease may vary with age, which makes the prevention of diarrhoea a challenge, especially in weaned pigs

Isolation and characterisation of porcine epidemic diarrhoea virus in Hungary – Short communication

Porcine epidemic diarrhoea virus (PEDV) is an emerging enteropathogen, causing great economic losses in the pig industry. After many years of quiescence, PEDV was detected in Hungary in 2016 with a recombination in its S gene. In order to determine the extent of this change, an attempt was made to isolate the recombinant PEDV. This study was extended with a variety of samples collected from three separate farms with newly identified PEDV in 2018. The recombinant PEDV from 2016 was isolated successfully along with three viruses from 2018, and one isolate from the new cases was used for whole genome determination. Whole genome sequence alignment revealed the highest identity with recombinant Hungarian and Slovenian PEDV within the low-pathogenic European viruses. This suggests that these recombinant PEDV are circulating in this area and may spread to other parts of the continent

Supporting biodiversity by prescribed burning in grasslands — A multi-taxa approach

There are contrasting opinions on the use of prescribed burning management in European grasslands. On the one hand, prescribed burning can be effectively used for the management of open landscapes, controlling dominant species, reducing accumulated litter or decreasingwildfire risk. On the other hand burning can have a detrimental impact on grassland biodiversity by supporting competitor grasses and by threatening several rare and endangered species, especially arthropods.We studied the effects of prescribed burning in alkaline grasslands of high conservation interest. Our aim was to test whether dormant-season prescribed burning can be an alternative conservation measure in these grasslands. We selected six sites in East-Hungary: in three sites, a prescribed fire was applied in November 2011, while three sites remained unburnt. We studied the effects of burning on soil characteristics, plant biomass and on the composition of vegetation and arthropod assemblages (isopods, spiders, ground beetles and rove beetles). Soil pH, organic matter, potassium and phosphorous did not change, but soluble salt content increased significantly in the burnt sites. Prescribed burning had several positive effects from the nature conservation viewpoint. Shannon diversity and the number of flowering shoots were higher, and the cover of the dominant grass Festuca pseudovinawas lower in the burnt sites. Graminoid biomasswas lower,while total, green and forb biomasswere higher in the burnt plots compared to the control. The key finding of our study was that prescribed burning did not decrease the abundance and diversity of arthropod taxa. Species-level analyses showed that out of themost abundant invertebrate species, 10were not affected, 1was negatively and 1was positively affected by burning. Moreover, our results suggest that prescribed burning leaving unburnt patches can be a viable management tool in open landscapes, because it supports plant diversity and does not threaten arthropods