TY  - JOUR
A1  - Wieczorek, Mareike
A1  - Kolmogorov, Alexei
A1  - Kruse, Stefan
A1  - Jacobsen, Inga
A1  - Nitze, Ingmar
A1  - Nikolaev, Anatoly N.
A1  - Heinrich, Ingo
A1  - Pestryakova, Luidmila Agafyevna
A1  - Herzschuh, Ulrike
T1  - Disturbance-effects on treeline larch-stands in the lower Kolyma River area (NE Siberia)
JF  - Silva Fennica : a quarterly journal for forest science
N2  - Tree stands in the boreal treeline ecotone are, in addition to climate change, impacted by disturbances such as fire, water-related disturbances and logging. We aim to understand how these disturbances affect growth, age structure, and spatial patterns of larch stands in the north-eastern Siberian treeline ecotone (lower Kolyma River region), an insufficiently researched region. Stand structure of Larix cajanderi Mayr was studied at seven sites impacted by disturbances. Maximum tree age ranged from 44 to 300 years. Young to medium-aged stands had, independent of disturbance type, the highest stand densities with over 4000 larch trees per ha. These sites also had the highest growth rates for tree height and stem diameter. Overall lowest stand densities were found in a polygonal field at the northern end of the study area, with larches growing in distinct " tree islands". At all sites, saplings are significantly clustered. Differences in fire severity led to contrasting stand structures with respect to tree, recruit, and overall stand densities. While a low severity fire resulted in low-density stands with high proportions of small and young larches, high severity fires resulted in high-density stands with high proportions of big trees. At waterdisturbed sites, stand structure varied between waterlogged and drained sites and latitude. These mixed effects of climate and disturbance make it difficult to predict future stand characteristics and the treeline position.
KW  - treeline
KW  - Larix cajanderi
KW  - Siberia
KW  - fire
KW  - stand structure
Y1  - 2017
U6  - https://doi.org/10.14214/sf.1666
SN  - 0037-5330
SN  - 2242-4075
VL  - 51
IS  - 3
PB  - The Finnish Society of Forest Science
CY  - Helsinki
ER  - 
TY  - JOUR
A1  - Frommhold, Martin
A1  - Heim, Arend
A1  - Barabanov, Mikhail
A1  - Maier, Franziska
A1  - Mühle, Ralf-Udo
A1  - Smirenski, Sergei M.
A1  - Heim, Wieland
T1  - Breeding habitat and nest-site selection by an obligatory "nest-cleptoparasite", the Amur Falcon Falco amurensis
JF  - Ecology and evolution
N2  - The selection of a nest site is crucial for successful reproduction of birds. Animals which re-use or occupy nest sites constructed by other species often have limited choice. Little is known about the criteria of nest-stealing species to choose suitable nesting sites and habitats. Here, we analyze breeding-site selection of an obligatory "nest-cleptoparasite", the Amur Falcon Falco amurensis. We collected data on nest sites at Muraviovka Park in the Russian Far East, where the species breeds exclusively in nests of the Eurasian Magpie Pica pica. We sampled 117 Eurasian Magpie nests, 38 of which were occupied by Amur Falcons. Nest-specific variables were assessed, and a recently developed habitat classification map was used to derive landscape metrics. We found that Amur Falcons chose a wide range of nesting sites, but significantly preferred nests with a domed roof. Breeding pairs of Eurasian Hobby Falco subbuteo and Eurasian Magpie were often found to breed near the nest in about the same distance as neighboring Amur Falcon pairs. Additionally, the occurrence of the species was positively associated with bare soil cover, forest cover, and shrub patches within their home range and negatively with the distance to wetlands. Areas of wetlands and fallow land might be used for foraging since Amur Falcons mostly depend on an insect diet. Additionally, we found that rarely burned habitats were preferred. Overall, the effect of landscape variables on the choice of actual nest sites appeared to be rather small. We used different classification methods to predict the probability of occurrence, of which the Random forest method showed the highest accuracy. The areas determined as suitable habitat showed a high concordance with the actual nest locations. We conclude that Amur Falcons prefer to occupy newly built (domed) nests to ensure high nest quality, as well as nests surrounded by available feeding habitats.
KW  - cleptoparasitism
KW  - fire
KW  - habitat use
KW  - machine learning
KW  - magpie
KW  - nest-site selection
KW  - random forest
Y1  - 2019
U6  - https://doi.org/10.1002/ece3.5878
SN  - 2045-7758
VL  - 9
IS  - 24
SP  - 14430
EP  - 14441
PB  - Wiley
CY  - Hoboken
ER  -