Search results for "Taiga"

Hot spots, indicator taxa, complementarity and optimal networks of taiga

2000

If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important gro…

Evaluation of the B‐method for determining actual evapotranspiration in a boreal forest from MODIS data

2007

Boreal forests occupy about 11% of the terrestrial surface and represent an important contribution to global energy balance. The ground measurement of daily evapotranspiration (LEd) is very difficult due to the limitations on experiments. The objective of this paper is to present and explore the applicability of the B-method for monitoring actual LEd in these ecosystems. The method shown in this paper allows us to determine the surface fluxes over boreal forests on a daily basis from instantaneous information registered in a conventional meteorological tower, as well as the canopy temperature (T c) retrieved by satellite. Images collected by the MODIS (moderate resolution imaging spectrorad…

Applying a framework for landscape planning under climate change for the conservation of biodiversity in the Finnish boreal forest

2015

Conservation strategies are often established without consideration of the impact of climate change. However, this impact is expected to threaten species and ecosystem persistence and to have dramatic effects towards the end of the 21st century. Landscape suitability for species under climate change is determined by several interacting factors including dispersal and human land use. Designing effective conservation strategies at regional scales to improve landscape suitability requires measuring the vulnerabilities of specific regions to climate change and determining their conservation capacities. Although methods for defining vulnerability categories are available, methods for doing this …

Burning of Logged Sites to Protect Beetles in Managed Boreal Forests

2007

: Natural disturbance–based management and conservation strategies are needed to protect forest biodiversity. Boreal forests of northern Europe are typically clearcut and otherwise intensively managed for timber production. As a result, natural disturbances such as forest fires have became rare and the volume of dead wood has decreased. These changes have had a profound negative effect on species that depend on dead wood (saproxylic). Therefore, it is important to determine whether modifications of forest management methods can enhance the survival of these species. In our study area in southern Finland, we determined whether burning of logged sites and leaving trees (i.e., retention trees)…

Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe

2019

Fire is a major disturbance agent in the boreal forest, influencing many current and future ecosystem conditions and services. Surprisingly few studies have attempted to improve the accuracy of fire-event reconstructions even though the estimates of the occurrence of past fires may be biased, influencing the reliability of the models employing those data (e.g. C stock, cycle). This study aimed to demonstrate how three types of fire proxies – fire scars from tree rings, sedimentary charcoal and, for the first time in this context, fungal spores of Neurospora – can be integrated to achieve a better understanding of past fire dynamics. By studying charcoal and Neurospora from sediment cores f…

Pētnieciskās darbības prasmes sekmēšana dabaszinību nodarbībās 5 - 6 gadus veciem bērniem

2017

Darba autors: Sintija Smoļenska. Darba nosaukums: Pētnieciskās darbības prasmes sekmēšana dabaszinību nodarbībās 5 - 6 gadus veciem bērniem. Darba mērķis: izpētīt vecākā pirmsskolas vecuma bērnu pētnieciskās darbības sekmēšanas iespējas dabaszinībās. Kvalifikācijas darbā ir vispārīgi raksturota 5 – 6 gadīgu bērnu attīstība, izanalizētas pētnieciskās darbības veicināšanas iespējas pirmsskolā, kā arī apskatīta pētniecisko darbību prasmju sekmēšana vecākās pirmsskolas vecuma grupas bērniem dabas zinību nodarbībās, veicot pētījumu par pētniecisko prasmju attīstības iespējām praktiski darbojoties ar bērniem. Pētījuma rezultāti parāda, ka pētniecisko prasmju attīstības pieaugums starp sākotnējo u…

Short communication: Driftwood provides reliable chronological markers in Arctic coastal deposits

2021

Originating from the boreal forest and often transported over large distances, driftwood characterizes many Arctic coastlines. Here we present a combined assessment of radiocarbon (14C) and dendrochronological (ring width) age estimates of driftwood samples to constrain the progradation of two Holocene beach-ridge systems near the Lena Delta in the Siberian Arctic (Laptev Sea). Our data show that the 14C ages obtained on syndepositional driftwood from beach deposits yield surprisingly coherent chronologies for the coastal evolution of the field sites. The dendrochronological analysis of wood from modern drift lines revealed the origin and recent delivery of the wood from the Lena River catc…

Effects of Canopy Gap Disturbance on Forest Birds in Boreal Forests

2013

We studied the effects of small-scale disturbance on breeding, forest passerine birds in an old-growth and managed boreal forests in northern Finland. Small-scale disturbance (< 2 ha) in an old-growth and managed forests originated from wind falls and small clear cuts. Continuous forest without gaps was used as a control for both management types (old-growth and managed forests). Passerines' response to disturbance was examined by estimating species richness and abundance of different ecological groups. Species richness and the total abundance of birds did not differ between gap and non-gap plots, neither did the abundance of most ecological groups. Management type or study year were the mo…

Alma Mater: 2012/ Ziema

2012

Effects of isolation, area and predators on invasion: A field experiment with artificial islands

2007

Abstract The three most important ecological factors affecting the success of island invasions are the area of the island, isolation of the island and occurrence of predators on the island. Traditionally, invasion success has been studied on natural islands, which partly explains the rarity of controlled and replicated experiments. Here we report results from a field experiment investigating the influence of the above three factors in artificial islands. As an experimental system, we used predatory mites and a nematode community occurring naturally in boreal coniferous forests. We found that all three factors had an effect on invasion success, but surprisingly, that there were no interactio…