The population biology of the arctic dwarf birch, Betula glandulosa: seed rain and the germinable seed bank

1988 ◽  
Vol 66 (10) ◽  
pp. 2055-2061 ◽  
Author(s):  
I. Michael Weis ◽  
Luise A. Hermanutz
Keyword(s):  
Seed Bank ◽  
Weight Distribution ◽  
Population Biology ◽  
Early Spring ◽  
Seed Rain ◽  
The Arctic ◽  
Low Density ◽  
Soil Cores ◽  
Betula Glandulosa ◽  
Dwarf Birch

The seed rain and seed bank of arctic dwarf birch, Betula glandulosa, were studied at Kuujjuaq, Que., and Tarr Inlet, near Iqaluit, N.W.T. At each site dispersing seeds were captured in sticky traps in three adjacent plots having locally high and low birch densities; soil cores were collected in parallel. Trap data indicate that birch samaras disperse principally during late fall and early spring. The number of samaras dispersed was significantly greater at Kuujjuaq than near Iqaluit and was greater in high- than in low-density areas. Samaras collected at Kuujjuaq were significantly heavier (x = 0.19 mg) than those from Tarr Inlet (x = 0.10 mg). Germination showed an asymptotic exponential weight dependence. From the weight distribution of samaras, we expected germination of 69.7% of samaras from Kuujjuaq. Few viable propagules were found in collections from the Iqaluit area; from their weight distribution 0.38% were expected to germinate. We predicted emergence from soil cores, using seed-trap and germination data, and tested predictions under greenhouse conditions. Observations and predictions agreed for low-density areas. At Kuujjuaq 248 emergences/m2 were predicted and 229 observed; at Iqaluit no emergences were predicted and none observed. In high-density plots at Kuujjuaq 9292 emergences/m2 were predicted and 2164 observed. Corresponding rates for Iqaluit were 2 and 17 emergences/m2, respectively. Differences in seed banks and recruitment indicate differences in the structure, dynamics, and reproductive biology of populations at the two sites.

Seed bank size and composition of Betula nana, Vaccinium uliginosum, and Campanula rotundifolia habitats in Svalbard and northern Norway

2003 ◽  
Vol 81 (3) ◽  
pp. 220-231 ◽  
Author(s):  
Inger Greve Alsos ◽  
Sigmund Spjelkavik ◽  
Torstein Engelskjøn
Keyword(s):  
Seed Bank ◽  
Seed Banks ◽  
Climatic Conditions ◽  
The Arctic ◽  
Soil Cores ◽  
Betula Nana ◽  
Northern Norway ◽  
Vaccinium Uliginosum ◽  
Campanula Rotundifolia ◽  
Alpine Habitats

The rare thermophilous species in the arctic archipelago of Svalbard are probably relicts from previous warmer periods and may be unable to reproduce sexually under the present climatic conditions. Germination of seeds, seed banks, and vegetative sprouts were studied in one Betula nana L., one Vaccinium uliginosum L., and two Campanula rotundifolia L. habitats in Svalbard. For comparison, one islet and three alpine habitats in northern Norway were studied. In each habitat, 50 soil cores (9.6 cm2) were collected and placed in a phytotron for germination tests. In Svalbard, no germinable seeds or seed bank of the three species were observed, whereas vegetative sprout densities were 83, 1060, and 21–1060/m2 for B. nana, V. uliginosum, and C. rotundifolia, respectively. In northern Norway, germination percentages of the collected seeds were 59, 10–27, and 15–40%, seed bank densities of seedlings 21–2765, 21–187, and 21–374/m2, and vegetative sprouts densities 94–206, 56–674, and 94–711/m2 for B. nana, V. uliginosum, and C. rotundifolia, respectively. Less thermophilous plant species produced germinable seeds in Svalbard, as 1247–5405 seedlings/m2 of 26 species germinated from the soil cores. In comparison, 5322–9626 seedlings/m2 of 43 species germinated in soil cores from the alpine habitats and 3534 seedlings/m2 of 26 species from the islet habitat. The results suggest that the most thermophilous species in Svalbard rarely produce germinable seeds under the present climatic conditions.Key words: arctic–alpine, Betula nana, Campanula rotundifolia, seed bank, sexual reproduction, thermophily, Vaccinium uliginosum.

scholarly journals Influence of Slope Direction on the Soil Seed Bank and Seedling Regeneration of Castanopsis hystrix Seed Rain

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 500
Author(s):  
Zong Zhao ◽  
Yong Liu ◽  
Hongyan Jia ◽  
Wensheng Sun ◽  
Angang Ming ◽  
...  
Keyword(s):  
Seed Bank ◽  
Temporal Dynamics ◽  
Soil Seed Bank ◽  
Soil Layer ◽  
Seed Rain ◽  
Seed Vigor ◽  
Study Results ◽  
The Impact ◽  
Mature Seeds

Objective: To investigate the impact of different slope directions on the quantity and quality of the soil seed bank and seedling germination process of Castanopsis hystrix plantations. Method: Fixed sample plots in forest stands of Castanopsis hystrix were established on different slope directions (sunny slope, semi-sunny slope, semi-shady slope, and shady slope). The characteristics of the forest stand were investigated, and per-wood scaling was carried out. The temporal dynamics of the seed rain and seed bank were quantified using seed rain collectors and by collecting soil samples from different depths. The quantity and quality of the seeds were determined, and the vigor of mature seeds was measured throughout the study. Results: (1) The diffusion of Castanopsis hystrix seed rain started in mid-September, reached its peak from late October to early November, and ended in mid-December. (2) The dissemination process, occurrence time, and composition of the seed rain varied between the different slope directions. The seed rain intensity on the semi-sunny slope was the highest (572.75 ± 9.50 grains∙m−2), followed by the sunny slope (515.60 ± 10.28 grains∙m−2), the semi-shady slope (382.13 ± 12.11 grains∙m−2), and finally the shady slope (208.00 ± 11.35 grains∙m−2). The seed rain on the sunny slope diffused earliest and lasted the longest, while the seed rain on the shady slope diffused latest and lasted the shortest time. Seed vigor and the proportion of mature seeds within the seed rain were greatest on the semi-sunny slope, followed by the sunny slope, semi-shady slope, and the shady slope. (3) From the end of the seed rain to August of the following year, the amount of total reserves of the soil seed banks was highest on the semi-sunny slope, followed by the sunny slope then the semi-shady slope, and it was the lowest on the shady slope. The amount of mature, immature, gnawed seeds and seed vigor of the soil seed bank in various slope directions showed a decreasing trend with time. The seeds of the seed bank in all slope directions were mainly distributed in the litter layer, followed by the 0–2 cm humus layer, and only a few seeds were present in the 2–5 cm soil layer. (4) The seedling density of Castanopsis hystrix differed significantly on the different slope directions. The semi-sunny slope had the most seedlings, followed by the sunny slope, semi-shady slope, and the shady slope. Conclusions: The environmental conditions of the semi-sunny slope were found to be most suitable for the seed germination and seedling growth of Castanopsis hystrix, and more conducive to the regeneration and restoration of its population.

scholarly journals Seasonal patterns in Arctic planktonic metabolism (Fram Strait – Svalbard region)

2013 ◽  
Vol 10 (3) ◽  
pp. 1451-1469 ◽  
Author(s):  
R. Vaquer-Sunyer ◽  
C. M. Duarte ◽  
J. Holding ◽  
A. Regaudie-de-Gioux ◽  
L. S. García-Corral ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Early Spring ◽  
The Arctic ◽  
Fram Strait ◽  
Metabolic Rates ◽  
Net Community Production ◽  
Western Sector ◽  
The Arctic Ocean ◽  
European Arctic ◽  
Community Production

Abstract. The metabolism of the Arctic Ocean is marked by extremely pronounced seasonality and spatial heterogeneity associated with light conditions, ice cover, water masses and nutrient availability. Here we report the marine planktonic metabolic rates (net community production, gross primary production and community respiration) along three different seasons of the year, for a total of eight cruises along the western sector of the European Arctic (Fram Strait – Svalbard region) in the Arctic Ocean margin: one at the end of 2006 (fall/winter), two in 2007 (early spring and summer), two in 2008 (early spring and summer), one in 2009 (late spring–early summer), one in 2010 (spring) and one in 2011 (spring). The results show that the metabolism of the western sector of the European Arctic varies throughout the year, depending mostly on the stage of bloom and water temperature. Here we report metabolic rates for the different periods, including the spring bloom, summer and the dark period, increasing considerably the empirical basis of metabolic rates in the Arctic Ocean, and especially in the European Arctic corridor. Additionally, a rough annual metabolic estimate for this area of the Arctic Ocean was calculated, resulting in a net community production of 108 g C m−2 yr−1.

scholarly journals Analysis of Arctic Spring Ozone Anomaly in the Phases of QBO and 11-year Solar Cycle for 1979–2011

2021 ◽  
Author(s):  
Yousuke Yamashita ◽  
Hideharu Akiyoshi ◽  
Masaaki Takahashi
Keyword(s):  
Solar Cycle ◽  
Climate Model ◽  
Polar Vortex ◽  
Reanalysis Data ◽  
Early Spring ◽  
The Arctic ◽  
Negative Anomaly ◽  
Late Winter ◽  
Quasi Biennial Oscillation ◽  
Biennial Oscillation

Arctic ozone amount in winter to spring shows large year-to-year variation. This study investigates Arctic spring ozone in relation to the phase of quasi-biennial oscillation (QBO)/the 11-year solar cycle, using satellite observations, reanalysis data, and outputs of a chemistry climate model (CCM) during the period of 1979–2011. For this duration, we found that the composite mean of the Northern Hemisphere high-latitude total ozone in the QBO-westerly (QBO-W)/solar minimum (Smin) phase is slightly smaller than those averaged for the QBO-W/Smax and QBO-E/Smax years in March. An analysis of a passive ozone tracer in the CCM simulation indicates that this negative anomaly is primarily caused by transport. The negative anomaly is consistent with a weakening of the residual mean downward motion in the polar lower stratosphere. The contribution of chemical processes estimated using the column amount difference between ozone and the passive ozone tracer is between 10–20% of the total anomaly in March. The lower ozone levels in the Arctic spring during the QBO-W/Smin years are associated with a stronger Arctic polar vortex from late winter to early spring, which is linked to the reduced occurrence of sudden stratospheric warming in the winter during the QBO-W/Smin years.

Lagrangian analysis of the northern polar vortex split in April 2020 during development of the Arctic ozone hole

2021 ◽  
Author(s):  
Jezabel Curbelo ◽  
Gang Chen ◽  
Carlos R. Mechoso
Keyword(s):  
Wave Train ◽  
Stratospheric Ozone ◽  
Polar Vortex ◽  
Early Spring ◽  
Ozone Hole ◽  
The Arctic ◽  
Late Winter ◽  
Lagrangian Analysis ◽  
The North ◽  
Vortex Split

<div>The evolution of the Northern Hemisphere stratosphere during late winter and early spring of 2020 was punctuated by outstanding events both in dynamics and tracer evolution. It provides an ideal case for study of the Lagrangian properties of the evolving flow and its connections with the troposphere. The events ranged from an episode of polar warming at upper levels in March, a polar vortex split into two cyclonic vortices at middle and lower levels in April, and a remarkably deep and persistent mass of ozone poor air within the westerly circulation throughout the period. The latter feature was particularly remarkable during 2020, which showed the lowest values of stratospheric ozone on record.</div><div> </div><div>We focus on the vortex split in April 2020 and we examine this split at middle as well as lower stratospheric levels, and the interactions that occurred between the resulting two vortices which determined the distribution of ozone among them. We also examine the connections among stratospheric and tropospheric events during the period.</div><div> </div><div>Our approach for analysis will be based on the application of Lagrangian tools to the flow field, based on following air parcels trajectories, examining barriers to the flow, and the activity and propagation of planetary waves. Our findings confirm the key role for the split played by a flow configuration with a polar hyperbolic trajectory and associated manifolds. A trajectory analysis illustrates the transport of ozone between the vortices during the split. We argue that these stratospheric events were linked to strong synoptic scale disturbances in the troposphere forming a wave train from the north Pacific to North America and Eurasia.</div><div><strong> </strong></div><div><strong>Reference:</strong><strong> </strong>J. Curbelo, G. Chen,  C. R. Mechoso. Multi-level analysis of the northern polar vortex split in April 2020 during development of the Arctic ozone hole. Earth and Space Science Open Archive. doi: 10.1002/essoar.10505516.1</div><div> </div><div><strong>Acknowledgements:</strong> NSF Grant AGS-1832842, RYC2018-025169 and EIN2019-103087.</div>

scholarly journals Background invertebrate herbivory on dwarf birch (Betula glandulosa-nana complex) increases with temperature and precipitation across the tundra biome

Polar Biology ◽  
2017 ◽  
Vol 40 (11) ◽  
pp. 2265-2278 ◽  
Author(s):  
Isabel C. Barrio ◽  
Elin Lindén ◽  
Mariska Te Beest ◽  
Johan Olofsson ◽  
Adrian Rocha ◽  
...  
Keyword(s):  
Temperature And Precipitation ◽  
Betula Glandulosa ◽  
Dwarf Birch ◽  
Invertebrate Herbivory

The effects of recreation disturbance on subalpine seed banks in the Rocky Mountains of Montana

2000 ◽  
Vol 78 (5) ◽  
pp. 577-582 ◽  
Author(s):  
Catherine Zabinski ◽  
Todd Wojtowicz ◽  
David Cole
Keyword(s):  
Organic Matter ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Density ◽  
Soil Cores ◽  
Bare Ground ◽  
Recreation Impacts ◽  
Natural Revegetation ◽  
Site Types

We investigated the soil seed bank in a subalpine ecosystem with patchy disturbance from camping. Soil cores were collected from three site types, heavily impacted, lightly impacted, and undisturbed, that differed in area of bare ground and depth of surface organic matter. We hypothesized that the density and composition of the seed bank would vary with depth of surface organic matter and distance from established vegetation. Seedling emergence was determined in the greenhouse. Seed density was significantly lower on disturbed sites, averaging 441 seeds/m2 on heavily impacted sites, 1495 seeds/m2 on lightly impacted sites, and 4188 seeds/m2 on undisturbed sites. Seed density declined exponentially with distance from established vegetation and increased with depth of surface organic matter. The number of species present did not vary across site types, but 10 species that occurred on lightly impacted and undisturbed sites were not present on heavily impacted sites. We concluded that disturbance that causes removal of surface organic matter can affect natural revegetation by lowering the density of propagules and affecting the species represented in the seed bank.Key words: seed bank, subalpine, patchy disturbance, recreation impacts.

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