scholarly journals Of Lemmings and Mussels: Trophic Cascade Drives Population Dynamics of Long-Tailed Ducks Breeding in Siberia

2022 ◽  
Author(s):  
Jukka Rintala ◽  
M. Hario ◽  
K. Laursen ◽  
A. P. Møller
Keyword(s):  
Population Dynamics ◽  
Breeding Success ◽  
Large Scale ◽  
Blue Mussel ◽  
Trophic Levels ◽  
The Arctic ◽  
Temperate Climate ◽  
North West ◽  
Breeding Grounds ◽  
The Baltic

Abstract Migratory animals experience very different environmental conditions at different times of the year, i.e., at the breeding grounds, during migration, and in winter. The long-tailed duck Clangula hyemalis breeds in the Arctic regions of the northern hemisphere and migrates to temperate climate zones, where it winters in marine environments. The breeding success of the long-tailed duck is affected by the abundances of predators (mainly Arctic fox Alopex lagopus) and their main prey species, lemmings Lemmus sibiricus and Dicrostonyx torquatus, whose population fluctuation is subject to climate change. In the winter quarters, long-tailed ducks mainly eat the blue mussel Mytilus edulis. We examined how North-west Siberian lemming dynamics affect long-tailed duck breeding success via predation pressure and how nutrient availability in the Baltic Sea influences long-tailed duck population size via mussel biomass and quality. The long-tailed duck population dynamics was predator-driven on the breeding grounds and resource-driven on the wintering grounds. Nutrients from fertilizer runoff from farmland stimulate mussel stocks and quality, supporting high long-tailed duck population sizes. The applied hierarchical analysis combining several trophic levels can be used for evaluating large-scale environmental factors that affect the population dynamics and abundance of migrants from one environment to another.

scholarly journals Arctic avian predators synchronise their spring migration with the northern progression of snowmelt

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Teja Curk ◽  
Ivan Pokrovsky ◽  
Nicolas Lecomte ◽  
Tomas Aarvak ◽  
David F. Brinker ◽  
...  
Keyword(s):  
Large Scale ◽  
Temporal Dynamics ◽  
The Arctic ◽  
Migratory Species ◽  
Migration Patterns ◽  
Predator Species ◽  
Movement Data ◽  
Breeding Grounds ◽  
Spatio Temporal ◽  
Spring Snowmelt

Abstract Migratory species display a range of migration patterns between irruptive (facultative) to regular (obligate), as a response to different predictability of resources. In the Arctic, snow directly influences resource availability. The causes and consequences of different migration patterns of migratory species as a response to the snow conditions remains however unexplored. Birds migrating to the Arctic are expected to follow the spring snowmelt to optimise their arrival time and select for snow-free areas to maximise prey encounter en-route. Based on large-scale movement data, we compared the migration patterns of three top predator species of the tundra in relation to the spatio-temporal dynamics of snow cover. The snowy owl, an irruptive migrant, the rough-legged buzzard, with an intermediary migration pattern, and the peregrine falcon as a regular migrant, all followed, as expected, the spring snowmelt during their migrations. However, the owl stayed ahead, the buzzard stayed on, and the falcon stayed behind the spatio-temporal peak in snowmelt. Although none of the species avoided snow-covered areas, they presumably used snow presence as a cue to time their arrival at their breeding grounds. We show the importance of environmental cues for species with different migration patterns.

scholarly journals Assessment of Wildfire Activity Development Trends for Eastern Australia Using Multi-Sensor Earth Observation Data

2021 ◽  
Vol 13 (24) ◽  
pp. 4975
Author(s):  
Michael Nolde ◽  
Norman Mueller ◽  
Günter Strunz ◽  
Torsten Riedlinger
Keyword(s):  
Large Scale ◽  
Fire Severity ◽  
The Arctic ◽  
Evergreen Forest ◽  
Temperate Climate ◽  
Significant Shift ◽  
Observation Data ◽  
Climate Zone ◽  
Eastern Australia ◽  
Fire Activity

Increased fire activity across the Amazon, Australia, and even the Arctic regions has received wide recognition in the global media in recent years. Large-scale, long-term analyses are required to postulate if these incidents are merely peaks within the natural oscillation, or rather the consequence of a linearly rising trend. While extensive datasets are available to facilitate the investigation of the extent and frequency of wildfires, no means has been available to also study the severity of the burnings on a comparable scale. This is now possible through a dataset recently published by the German Aerospace Center (DLR). This study exploits the possibilities of this new dataset by exemplarily analyzing fire severity trends on the Australian East coast for the past 20 years. The analyzed data is based on 3503 tiles of the ESA Sentinel-3 OLCI instrument, extended by 9612 granules of the NASA MODIS MOD09/MYD09 product. Rising trends in fire severity could be found for the states of New South Wales and Victoria, which could be attributed mainly to developments in the temperate climate zone featuring hot summers without a dry season (Cfa). Within this climate zone, the ecological units featuring needleleaf and evergreen forest are found to be mainly responsible for the increasing trend development. The results show a general, statistically significant shift of fire activity towards the affection of more woody, ecologically valuable vegetation.

scholarly journals Population dynamics of the White Stork Ciconia ciconia in Slovenia between 1999 and 2010

Acrocephalus ◽  
2010 ◽  
Vol 31 (145-146) ◽  
pp. 101-114 ◽  
Author(s):  
Damijan Denac
Keyword(s):  
Population Dynamics ◽  
Breeding Success ◽  
Weather Conditions ◽  
Breeding Population ◽  
White Stork ◽  
Breeding Period ◽  
Ciconia Ciconia ◽  
White Storks ◽  
Breeding Grounds ◽  
Unfavourable Weather

Population dynamics of the White StorkCiconia ciconiain Slovenia between 1999 and 2010Between 1999 and 2010, an annual census of the White StorkCiconia ciconiabreeding population was carried out in Slovenia using standardised methods. The Stork's population was concentrated in the NE and SE parts of Slovenia. In the 1999-2010 period, the breeding range of its population in Slovenia expanded in NW direction (the Savska ravan region), in SW direction (the Notranjsko podolje and Pivško podolje regions), but the species also colonized a part between Central and SE Slovenia (Dolenjsko podolje). Between 193 and 240 pairs were breeding during the study period, 209 pairs on average (HPa). The largest number of breeding pairs was recorded in 2004, the smallest in 2005. During the study period, breeding pairs (HPa) occupied 350 discrete nests in total. Average number of breeding pairs that raised juveniles (HPm) was 161. The highest fecundity was recorded in 2004, when 534 juveniles (JZG) fledged, the lowest in 2006, with only 219 fledged juveniles. On average, 414 juveniles fledged per year. The breeding pairs' (JZa) average breeding success in these 12 years was 2.02, the highest in 2000 (2.41), the lowest in 2006 (1.09). Average breeding success for the successful breeding pairs (JZm) was 2.57. The highest was in 2007 (2.94), the lowest in 2006 (2.07). The largest number of breeding pairs in 2004 and 2008 can be explained by the favourable fecundity in the population in 2000 and 2004, as juveniles become sexually mature at the age of 3-5 years, and at that age they generally return to the breeding grounds for the first time. The lowest number of breeding pairs and poor breeding success in 2005 and 2006 was caused by late arrival of White Storks to the breeding grounds and by unfavourable weather conditions during the breeding period. The pattern of nests placement did not change generally during the last 12 years. The largest proportion of nests was positioned on various kinds of poles (81%) and on chimneys (18%). In total, 27 area surveyors and 239 assistants helped in census realisation.

scholarly journals Invader removal triggers competitive release in a threatened avian predator

2021 ◽  
Vol 118 (31) ◽  
pp. e2102859118
Author(s):  
J. David Wiens ◽  
Katie M. Dugger ◽  
J. Mark Higley ◽  
Damon B. Lesmeister ◽  
Alan B. Franklin ◽  
...  
Keyword(s):  
Invasive Species ◽  
Population Dynamics ◽  
Large Scale ◽  
Trophic Levels ◽  
Spotted Owl ◽  
Avian Predator ◽  
Competitive Release ◽  
Spotted Owls ◽  
Barred Owls ◽  
Positive Effect

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before–after control–impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species.

scholarly journals Ciliate and mesozooplankton community response to increasing CO<sub>2</sub> levels in the Baltic Sea: insights from a large-scale mesocosm experiment

2017 ◽  
Vol 14 (2) ◽  
pp. 447-466 ◽  
Author(s):  
Silke Lischka ◽  
Lennart T. Bach ◽  
Kai-Georg Schulz ◽  
Ulf Riebesell
Keyword(s):  
Baltic Sea ◽  
Chlorophyll A ◽  
Large Scale ◽  
Community Response ◽  
Trophic Levels ◽  
The Baltic Sea ◽  
Mesozooplankton Community ◽  
Shannon Diversity ◽  
Carbon Transfer ◽  
The Baltic

Abstract. Community approaches to investigating ocean acidification (OA) effects suggest a high tolerance of micro- and mesozooplankton to carbonate chemistry changes expected to occur within this century. Plankton communities in the coastal areas of the Baltic Sea frequently experience pH variations partly exceeding projections for the near future both on a diurnal and seasonal basis. We conducted a large-scale mesocosm CO2 enrichment experiment ( ∼  55 m3) enclosing the natural plankton community in Tvärminne–Storfjärden for 8 weeks during June–August 2012 and studied community and species–taxon response of ciliates and mesozooplankton to CO2 elevations expected for this century. In addition to the response to fCO2, we also considered temperature and chlorophyll a variations in our analyses. Shannon diversity of ciliates significantly decreased with fCO2 and temperature with a greater dominance of smaller species. The mixotrophic Myrionecta rubra seemed to indirectly and directly benefit from higher CO2 concentrations in the post-bloom phase through increased occurrence of picoeukaryotes (most likely Cryptophytes) and Dinophyta at higher CO2 levels. With respect to mesozooplankton, we did not detect significant effects for either total abundance or for Shannon diversity. The cladocera Bosmina sp. occurred at distinctly higher abundance for a short time period during the second half of the experiment in three of the CO2-enriched mesocosms except for the highest CO2 level. The ratio of Bosmina sp. with empty to embryo- or resting-egg-bearing brood chambers, however, was significantly affected by CO2, temperature, and chlorophyll a. An indirect CO2 effect via increased food availability (Cyanobacteria) stimulating Bosmina sp. reproduction cannot be ruled out. Although increased regenerated primary production diminishes trophic transfer in general, the presence of organisms able to graze on bacteria such as cladocerans may positively impact organic matter transfer to higher trophic levels. Thus, under increasing OA in cladoceran-dominated mesozooplankton communities, the importance of the microbial loop in the pelagic zone may be temporarily enhanced and carbon transfer to higher trophic levels may be stimulated.

scholarly journals Micro- and mesozooplankton community response to increasing CO<sub>2</sub> levels in the Baltic Sea: insights from a large-scale mesocosm experiment

2015 ◽  
Vol 12 (23) ◽  
pp. 20025-20070 ◽  
Author(s):  
S. Lischka ◽  
L.T. Bach ◽  
K.-G. Schulz ◽  
U. Riebesell
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Microbial Loop ◽  
Trophic Levels ◽  
Carbonate Chemistry ◽  
The Baltic Sea ◽  
Shannon Diversity ◽  
Carbon Transfer ◽  
Myrionecta Rubra ◽  
The Baltic

Abstract. Community approaches investigating ocean acidification (OA) effects suggest a high tolerance of micro- and mesozooplankton to carbonate chemistry changes expected to occur within this century. Plankton communities in the coastal areas of the Baltic Sea frequently experience pH variations partly exceeding projections for the near future both on a diurnal and seasonal basis, thus some level of tolerance/adaptation may be expected. We conducted a large-scale mesocosm CO2 enrichment experiment (~ 55 m3) enclosing the natural plankton community in Tvärminne/Storfjärden for eight weeks during June–August 2012 and studied community and species/taxon response of microzooplankton (ciliates) and mesozooplankton to CO2 elevations expected for this century. Besides the response to fCO2 and associate changes in carbonate chemistry speciation, we also considered temperature and chlorophyll a variations in our analyses. Shannon diversity of microzooplankton significantly decreased with fCO2 and temperature with a greater dominance of smaller species. Small sized ciliates (Myrionecta rubra, Balanion comatum, Strombidium cf. epidemum, Strobilidium sp.) showed significant relations with one or more of the factors. The phototrophic Myrionecta rubra seemed to directly benefit from higher CO2 concentrations and showed increased abundance in the pre-bloom phase. With respect to meszooplankton, we neither detected significant effects for total abundance nor for Shannon diversity. The cladocera Bosmina occurred at distinctly higher abundance (more than twice as high compared to the control mesocosms) for a short time period during the second half of the experiment in three of the CO2-enriched mesocosms except for the highest CO2 level. The ratio of Bosmina with empty to embryo/resting egg bearing brood chambers, however, was significantly affected by all three factors. An indirect CO2 effect via increased food availability stimulating Bosmina reproduction is suggested, but too low sampling frequency of this highly flexible organism probably entailed proving a significant relation with fCO2. Filter-feeding cladocerans effectively transfer microbial loop carbon to higher trophic levels. Thus, under increasing OA in cladoceran dominated mesozooplankton communities the importance of the microbial loop in the pelagic zone may be enhanced and carbon transfer to higher trophic levels stimulated.

scholarly journals Climate change and ocean acidification impacts on lower trophic levels and the export of organic carbon to the deep ocean

2013 ◽  
Vol 10 (9) ◽  
pp. 5831-5854 ◽  
Author(s):  
A. Yool ◽  
E. E. Popova ◽  
A. C. Coward ◽  
D. Bernie ◽  
T. R. Anderson
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Ocean Acidification ◽  
21St Century ◽  
Trophic Level ◽  
Large Scale ◽  
World Ocean ◽  
Trophic Levels ◽  
The Arctic ◽  
Marine Biota

Abstract. Most future projections forecast significant and ongoing climate change during the 21st century, but with the severity of impacts dependent on efforts to restrain or reorganise human activity to limit carbon dioxide (CO2) emissions. A major sink for atmospheric CO2, and a key source of biological resources, the World Ocean is widely anticipated to undergo profound physical and – via ocean acidification – chemical changes as direct and indirect results of these emissions. Given strong biophysical coupling, the marine biota is also expected to experience strong changes in response to this anthropogenic forcing. Here we examine the large-scale response of ocean biogeochemistry to climate and acidification impacts during the 21st century for Representative Concentration Pathways (RCPs) 2.6 and 8.5 using an intermediate complexity global ecosystem model, MEDUSA-2.0. The primary impact of future change lies in stratification-led declines in the availability of key nutrients in surface waters, which in turn leads to a global decrease (1990s vs. 2090s) in ocean productivity (−6.3%). This impact has knock-on consequences for the abundance of the low trophic level biogeochemical actors modelled by MEDUSA-2.0 (−5.8%), and these would be expected to similarly impact higher trophic level elements such as fisheries. Related impacts are found in the flux of organic material to seafloor communities (−40.7% at 1000 m), and in the volume of ocean suboxic zones (+12.5%). A sensitivity analysis removing an acidification feedback on calcification finds that change in this process significantly impacts benthic communities, suggesting that a~better understanding of the OA-sensitivity of calcifying organisms, and their role in ballasting sinking organic carbon, may significantly improve forecasting of these ecosystems. For all processes, there is geographical variability in change – for instance, productivity declines −21% in the Atlantic and increases +59% in the Arctic – and changes are much more pronounced under RCP 8.5 than the RCP 2.6 scenario.

Synchrony in Svalbard reindeer population dynamics

2003 ◽  
Vol 81 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ronny Aanes ◽  
Bernt-Erik Sæther ◽  
Erling J Solberg ◽  
Sondre Aanes ◽  
Olav Strand ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Rangifer Tarandus ◽  
Regional Climate ◽  
The Arctic ◽  
Climate Index ◽  
Local Climate ◽  
Svalbard Reindeer ◽  
Reindeer Population ◽  
The Arctic Oscillation

We examined potential synchrony in the growth rates of three Svalbard reindeer (Rangifer tarandus platyrhynchus) populations and tested whether this pattern may result from correlated environmental variation. Two neighbouring populations had synchronized dynamics during the study period, while a more distant population showed different temporal variation. Climatic forcing (the Moran effect) was a likely synchronizing mechanism in combination with contrasting density-dependence patterns between the synchronous and asynchronous populations. Local climate was a more important synchronizing agent than a regional climate index (the Arctic Oscillation). Nevertheless, our results also suggest that variation in climate at a large scale may be important. Based on indirect measurements of dispersal/migration, our findings indicate that this factor does not play a key role in the spatial synchrony of Svalbard reindeer population dynamics.

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

Paleoecological study of bottom sediments of the lake Goluboye (Karelian Isthmus) according to the results of diatom analysis

2019 ◽  
pp. 265-269
Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Modern Science ◽  
Karelian Isthmus ◽  
The Baltic Sea ◽  
Diatom Analysis ◽  
North West ◽  
The North ◽  
Important Direction ◽  
The Baltic

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.

Sign in / Sign up

Export Citation Format

Share Document