Eesti Looduse fotovõistlus
2012/10



   Eesti Looduse
   viktoriin


   Eesti Looduse
   fotovõistlus 2012




   AIANDUS.EE

Eesti Loodus
summary EL 2012/10

Go, go, birds of passage
Tuul Sepp takes a look at the most dangerous period in most birds’ life: the migration from nesting areas to wintering areas and back. About 1800 species of world’s 10 000 bird species are migratory birds. The length of migration differs a lot, ranging from a few hundred kilometers to almost 30 000 km in the case of arctic tern. Some prefer real warmth, travelling to Africa, while for others Estonia is warm enough for wintering. Some travel during night, others during daytime. Migration poses a number of severe dangers: weather, predators, but also illnesses. But still, migrating has proved to be efficient for the survival of species. The article gives an exciting overview of the number of factors related to bird migration.

Estonian Nature enquires
Aivar Leito explains the idea behind Vladimir Putin „teaching“ the white cranes to migrate south.
Andres Kuresoo introduces modern bird radars.

Migratory birds in folk tradition
Mall Hiiemäe looks back on folk beliefs about bird migration. Migratory birds have been believed to be communicators between the worlds of the living and the dead. The most beliefs have been recorded about common cranes.

The tiny inhabitants of tiny waterbodies
Maarja Vaikre and Liina Remm introduce seemingly unimportant habitats, which actually have a very vital role in nature. Tiny waterbodies have low water depth and they dry out during droughty summers. The biota of such tiny habitats is influenced by several factors: period of water, acidity, content of oxygen, plants and the surroundings of the waterbody. The species composition may change with seasons. The tiny waterbodies pose challenges for theories of ecology and offer several discoveries to be made.

Maintenance of ponds supports biodiversity
Voldemar Rannap, Riinu Rannap and Ilona Lepik give advice on how to found and maintain ponds in a way to support biodiversity. Small ponds used to be common landscape elements, but have become rare with changes in land use. Ponds have a very diverse, but small-scale biota, most of them being invertebrates. It is important to remember that fish should not be introduced into such small ponds, as they consume all the biodiversity. Also, ponds should be steadily maintained, otherwise they overgrow with bushes and biodiversity will be decreased.

Alien fungi on woodchip and bark mulch
Laura Pärtel and Tõnu Ploompuu draw attention to non-native species of fungi which have not been much noticed in Estonia. There are several invasive fungal species that grow specifically on bark and woodchip mulches, which form very favorable habitats for timber-related species. Although the number of species of these habitats is not big, the specimens often grow very large in size. The article introduces some of the species found from Estonia and Europe.

Interview: The fish’ tail started to rot already billions of years ago
Toomas Kukk has interviewed Elga Mark-Kurik, a paleo-ichthyologist.

Ash dieback is caused by another fungus, a invasive pathogen
Tiia Drenkhan, Rein Drenkhan and Märt Hanso describe the nature and influence of the pathogen Hymenoscyphus pseudoalbidus, the causal agent of ash dieback. This pathogen can be differentiated from a close species, Hymenoscyphus albidus, which was previously considered the cause for ash dieback, only by DNA analysis.

Practical tips: how to measure high trees?
Hendrik Relve considers the common bottleneck of dendrological fieldworks: it is not easy to measure the exact height of trees. Based on examples of the highest trees of Estonia, the author demonstrates how different measuring methods give quite different results, with differences of about 2–3 metres for trees higher than 40 metres. The distance from the measure trees has to be bigger than the height of the tree.

Protected area: The Mädapea oak stand
Riina Kotter takes the reader to a landscape protection area near Rakvere, where one can find majestic oak stands and maintained wooded meadows. The Mädapea oak stand is a remnant of a former large oak wooded meadow, and the average age of the trees is 250 years. There are also wooded grasslands in the area, as well as broad-leaved deciduous forests, providing favorable habitats for rare fungal and lichen species.



28/11/2012
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