Search results for "dragon"
showing 10 items of 50 documents
Stream restorations with meanders increase dragonfly and damselfly diversity and abundance, including an endangered species.
2021
10 pages; International audience; This study presents examples of successful restoration projects for biodiversity conservation. In West France, the Pinail National Nature Reserve is a protected wetland interspersed with more than 6000 ponds. This wetland is inhabited by 50 species of Odonata and thus is a key biodiversity area for damselflies and dragonflies conservation. In the past, when the limestone was exploited, the streams of the plateau were artificially channeled rectilinearly, running to the Vienne River. Eventually streams were blocked by biomass and sediments resulting in water flowing mainly underground. In 2011, two restoration projects dug and recreated lost habitats such as…
2018
Odonate (damselfly and dragonfly) species richness and species occupancy frequency distributions (SOFDs) were analyzed in relation to geographical location in standing waters (lakes and ponds) in Fennoscandia, from southern Sweden to central Finland. In total, 46 dragonfly and damselfly species were recorded from 292 waterbodies. Species richness decreased to the north and increased with waterbody area in central Finland, but not in southern Finland or in Sweden. Species occupancy ranged from 1 up to 209 lakes and ponds. Over 50% of the species occurred in <10% of the waterbodies, although this proportion decreased to the north. In the southern lakes and ponds, none of the species occurred …
The probable function of abdominal contractions and liquid drops during the emergence of Zygoptera and Anisoptera (Odonata)
2016
The transition between larval and adult stage in amphibious insects is called emergence. During emergence abdominal contractions and excretion of liquid drops can be observed in several insect orders. Since the function of these processes is not yet known in odonates, this study examines the probable function of abdominal contractions and excretion of liquid drops in Zygoptera and Anisoptera. By subdividing the emergence into 12 successive stages and counting abdominal contractions as well as the excreted liquid drops during these stages we set up a systematic data collection. In all investigated individuals, both processes began in the middle of the entire emergence. We found that abdomina…
Ruiša pūķgalve Latvijas Universitātes Muzeja herbārijā
2020
Par Gada augu 2020 tika izvēlēts Latvijas aizsargājamais augs ruiša pūķgalve, ko Latvijā pirmo reizi atradis dabaspētnieks Eduards Lēmanis (1841 – 1902) 1883. gadā Antonopolē. Tas kopā ar citiem ruiša pūķgalves herbārija paraugiem glabājas Latvijas Universitātes Muzeja Botānikas un mikoloģijas kolekcijās. Tie ir gan Latvijā, gan Igaunijā ievākti eksemplāri laika posmā no 1848. līdz 1977. gadam.
Dracocephalum ruyschiana L. (pie Prensas (Antonopole))
1883
Nordischer Drachenkopf: Heidekieferwald bei Presna (Antonopol); Lichte Waldhange bei Nummern (1888.10.07.) /// Ruiša pūķgalve; Atradne: viršu priežu mežs pie Prensas (Antonopole); gaiša meža nogāze pie Numernes. /// Northern Dragon-head, deposit: heather pine forest near Prensa (Antonopole); a bright forest slope near Numerne. [Attēls no LU Muzeja kolekcijas Herbarium Latvicum (RIG II); (BOT1029_21)]
Lifetime egg production of captive libellulids (Odonata)
2015
The estimation of lifetime egg production (LEP) is a central question in ecology, since the number of eggs produced determines the potential size of the following generation. In this study, I tried to obtain a rough estimation of the LEPs in libellulids in outdoor cages. The main questions were: (1) does hand feeding influence females’ life history traits; (2) how long is the maturation period and the lifespan; (3) does the quality/quantity of eggs vary with female age or size; and (4) how many eggs do females lay in their lifetime? I installed two outdoor cages and kept individually marked specimens of Orthetrum coerulescens and Sympetrum striolatum under semi-natural circumstances. Orthet…
Zvaigžņotā Debess: 2010/11, Ziema (210)
2010
Contents: “ZVAIGŅOTĀ DEBESS” FORTY YEARS AGO: Bursting Stars. J. Francman (abridged). Geodesists Help Renew the Spire of St. Peter’s Church. J. Klētnieks (abridged). DEVELOPMENTS in SCIENCE: The Solar Neutrino Problem. O. Smirnova. NEWS: At Last the Planet at the Star β Pictoris Is Imaged. A. Alksnis, Z. Alksne. SPACE RESEARCH and EXPLORATION: The Trail of an Asteroid Reveals a Recent Collision. A. Alksnis. INTERNATIONAL YEAR of ASTRONOMY 2009: International Year of Astronomy 2009 in Philately. The Rest of the World except Series EUROPA (concluded). J. Limansky. ACADEMIC STAFF of the UNIVERSITY of LATVIA: Assistant Professor in Physics Ojārs Šmits (24.04.1930.-14.03.1993.) of the Latvian Un…
Recensione di GALLIANI C., SCHERINI R. & PIGLIA A., 2017. Dragonflies and damselflies of Europe. A scientific approach to the identification of Europ…
2018
Recensione di GAUCI C., 2018. Dragonflies and damselflies of the Maltese islands. Birdlife Malta, Malta: 1-150. € 20
2018
The effect of peatland drainage and restoration on Odonata species richness and abundance
2015
Background Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration efforts. Results Here, we studied how abundance and species richness of Odonata (dragonflies and damselflies) respond to restoration. We sampled larvae in three sites (restored, drained, pristine) on each o…