Integrated crop-livestock versus conventional systems: use of soil indicators to detect short-term changes during seasonal variation

A population of the mound-building meat ant, Iridomyrmex purpureus s. s., was studied from 1971 to 1974 near the cool, wet end of its South Australian range. Seasonal variation in the numbers of nest mounds, and in number of nest entrance holes used by the population, indicate that it is under climatic stress in winter and summer. It is also subject to human interference and many mounds have been damaged; the fate of such colonies suggests that the mounds affect nest temperatures and are important in reducing winter stress. Comparison of parts of the population from areas differing in aspect and drainage shows that colony size and structure are controlled by rates of growth and survival of nests, depending largely on summer and winter stress respectively. The latter appears to be the critical factor in this population.

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Seasonal Variation of Chemical Species Associated With Short-Term Mortality Effects of PM2.5 in Xi’an, a Central City in China

American Journal of Epidemiology ◽

10.1093/aje/kwr342 ◽

2012 ◽

Vol 175 (6) ◽

pp. 556-566 ◽

Cited By ~ 150

Author(s):

Wei Huang ◽

Junji Cao ◽

Yebin Tao ◽

Lingzhen Dai ◽

Shou-En Lu ◽

...

Keyword(s):

Seasonal Variation ◽

Central City ◽

Chemical Species ◽

Short Term ◽

Short Term Mortality

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A Snow-bank Push Mechanism for the Formation of Some “Annual” Moraine Ridges

Journal of Glaciology ◽

10.1017/s0022143000021535 ◽

1977 ◽

Vol 18 (78) ◽

pp. 77-85 ◽

Cited By ~ 30

Author(s):

Richard V. Birnie

Keyword(s):

Seasonal Variation ◽

Short Term ◽

South Georgia ◽

Ice Edge

AbstractIce-marginal features in South Georgia include minor moraine ridges running approximately parallel to the ice margin and developed as superficial forms in various depths of till. It is suggested that these developed as ice-contact landforms, some being created by the interaction of the ice edge and abutting marginal snow bank, whilst the glacier is advancing. This advance is essentially short-term, being part of a seasonal variation in the position of the ice margin. “Snow-bank push” is the term proposed to describe this mechanism of ridge formation.

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Fast response of fungal and prokaryotic communities to climate change manipulation in two contrasting tundra soils

Environmental Microbiome ◽

10.1186/s40793-019-0344-4 ◽

2019 ◽

Vol 14 (1) ◽

Author(s):

Jana Voříšková ◽

Bo Elberling ◽

Anders Priemé

Keyword(s):

Organic Matter ◽

Seasonal Variation ◽

Snow Cover ◽

Bacterial Communities ◽

Winter Precipitation ◽

Fungal Communities ◽

Tundra Soils ◽

Short Term ◽

Fungal Community Composition ◽

Climate Manipulation

Abstract Background Climate models predict substantial changes in temperature and precipitation patterns across Arctic regions, including increased winter precipitation as snow in the near future. Soil microorganisms are considered key players in organic matter decomposition and regulation of biogeochemical cycles. However, current knowledge regarding their response to future climate changes is limited. Here, we explore the short-term effect of increased snow cover on soil fungal, bacterial and archaeal communities in two tundra sites with contrasting water regimes in Greenland. In order to assess seasonal variation of microbial communities, we collected soil samples four times during the plant-growing season. Results The analysis revealed that soil microbial communities from two tundra sites differed from each other due to contrasting soil chemical properties. Fungal communities showed higher richness at the dry site whereas richness of prokaryotes was higher at the wet tundra site. We demonstrated that fungal and bacterial communities at both sites were significantly affected by short-term increased snow cover manipulation. Our results showed that fungal community composition was more affected by deeper snow cover compared to prokaryotes. The fungal communities showed changes in both taxonomic and ecological groups in response to climate manipulation. However, the changes were not pronounced at all sampling times which points to the need of multiple sampling in ecosystems where environmental factors show seasonal variation. Further, we showed that effects of increased snow cover were manifested after snow had melted. Conclusions We demonstrated rapid response of soil fungal and bacterial communities to short-term climate manipulation simulating increased winter precipitation at two tundra sites. In particular, we provide evidence that fungal community composition was more affected by increased snow cover compared to prokaryotes indicating fast adaptability to changing environmental conditions. Since fungi are considered the main decomposers of complex organic matter in terrestrial ecosystems, the stronger response of fungal communities may have implications for organic matter turnover in tundra soils under future climate.

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Short-Term Dynamics of Tidepool Fish Community: Diel and Seasonal Variation

Environmental Biology of Fishes ◽

10.1007/s10641-006-9024-5 ◽

2006 ◽

Vol 76 (2-4) ◽

pp. 221-235 ◽

Cited By ~ 16

Author(s):

Seiji Arakaki ◽

Mutsunori Tokeshi

Keyword(s):

Seasonal Variation ◽

Fish Community ◽

Short Term

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The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya

Animal Science ◽

10.1017/s000335610000266x ◽

1986 ◽

Vol 43 (3) ◽

pp. 447-457 ◽

Cited By ~ 4

Author(s):

A. B. Carles ◽

W. A. K. Kipngeno

Keyword(s):

Time Series ◽

Seasonal Variation ◽

New Zealand ◽

Time Series Analysis ◽

Oestrous Cycle ◽

Significant Source ◽

Short Term ◽

Series Analysis ◽

The Mean

ABSTRACTA study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the length of the oestrous cycle (P < 0·01). The mean lengths of the oestrous cycle were 17·2 (s.d. 3·21), 17·5 (s.d. 2·24), 17·9 (s.d. 2·99), 17·5 (s.d. 2·57) and 16·5 (s.d. 3·41) days for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively.The mean percentage of ewes of the different breeds showing oestrus in 20-day periods were 69·8 (s.d. 22·57), 49·9 (s.d. 18·67), 63·4 (s.d. 25·70), 79·2 (s.d. 20·30) and 33·2 (s.d. 23·50) % for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. Time-series analysis did not detect any evidence of seasonal variation in oestrous activity, although there was an indication that the Merino and Romney Marsh breeds showed a marked increase in oestrous activity following, the introduction of rams. It was concluded that the variation in level of oestrous activity was short term and random.

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Effect of short-term versus long-term grassland management and seasonal variation in organic and conventional dairy farming on the composition of bulk tank milk

Journal of Dairy Science ◽

10.3168/jds.2012-5765 ◽

2013 ◽

Vol 96 (9) ◽

pp. 5793-5810 ◽

Cited By ~ 17

Author(s):

S.A. Adler ◽

S.K. Jensen ◽

E. Govasmark ◽

H. Steinshamn

Keyword(s):

Seasonal Variation ◽

Grassland Management ◽

Dairy Farming ◽

Short Term ◽

Bulk Tank Milk ◽

Bulk Tank

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Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0186 ◽

2013 ◽

Vol 368 (1627) ◽

pp. 20130186 ◽

Cited By ~ 73

Author(s):

Jasmin A. Godbold ◽

Martin Solan

Keyword(s):

Seasonal Variation ◽

Ocean Acidification ◽

Environmental Conditions ◽

Nutrient Release ◽

Interactive Effects ◽

Long Term Effects ◽

Short Term ◽

Climatic Forcing ◽

Species Responses

Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete ( Alitta virens ) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing.

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