Influence of long-term climatic changes on breeding of the Chilean flamingo in Mar Chiquita, Córdoba, Argentina

Hydrobiologia ◽  
2012 ◽  
Vol 697 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Enrique H. Bucher ◽  
Erio Curto
Keyword(s):  
Climatic Changes

A quantitative synthesis of Holocene vegetation change in Nigeria (Western Africa)

The Holocene ◽  
2021 ◽  
pp. 095968362110331
Author(s):  
Matthew Adesanya Adeleye ◽  
Simon Edward Connor ◽  
Simon Graeme Haberle
Keyword(s):  
Vegetation Change ◽  
Climatic Changes ◽  
The Holocene ◽  
Continental Scale ◽  
Western Africa ◽  
Chord Distance ◽  
Quantitative Synthesis ◽  
Climatic Regime ◽  
Pollen Records

Understanding long-term (centennial–millennial scale) ecosystem stability and dynamics are key to sustainable management and conservation of ecosystem processes under the currently changing climate. Fossil pollen records offer the possibility to investigate long-term changes in vegetation composition and diversity on regional and continental scales. Such studies have been conducted in temperate systems, but are underrepresented in the tropics, especially in Africa. This study attempts to synthesize pollen records from Nigeria (tropical western Africa) and nearby regions to quantitatively assess Holocene regional vegetation changes (turnover) and stability under different climatic regimes for the first time. We use the squared chord distance metric (SCD) to assess centennial-scale vegetation turnover in pollen records. Results suggest vegetation in most parts of Nigeria experienced low turnover under a wetter climatic regime (African Humid Period), especially between ~8000 and 5000 cal year BP. In contrast, vegetation turnover increased significantly under the drier climatic regime of the late-Holocene (between ~5000 cal year BP and present), reflecting the imp role of moisture changes in tropical west African vegetation dynamics during the Holocene. Our results are consistent with records of vegetation and climatic changes in other parts of Africa, suggesting the Holocene pattern of vegetation change in Nigeria is a reflection of continental-scale climatic changes.

scholarly journals Thermal structure and response to long-term climatic changes in Lake Qiandaohu, a deep subtropical reservoir in China

2014 ◽  
Vol 59 (4) ◽  
pp. 1193-1202 ◽  
Author(s):  
Yunlin Zhang ◽  
Zhixu Wu ◽  
Mingliang Liu ◽  
Jianbo He ◽  
Kun Shi ◽  
...  
Keyword(s):  
Thermal Structure ◽  
Climatic Changes

scholarly journals Interannual and long-term changes in the trophic state of a multibasin lake: effects of morphology, climate, winter aeration, and beaver activity

2016 ◽  
Vol 73 (3) ◽  
pp. 445-460 ◽  
Author(s):  
Dale M. Robertson ◽  
William J. Rose ◽  
Paul C. Reneau
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Secchi Depth ◽  
Climatic Changes ◽  
Main Flow ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Long Term Changes ◽  
P Sources

Little St. Germain Lake (LSG), a relatively pristine multibasin lake in Wisconsin, USA, was examined to determine how morphologic (internal), climatic (external), anthropogenic (winter aeration), and natural (beaver activity) factors affect the trophic state (phosphorus, P; chlorophyll, CHL; and Secchi depth, SD) of each of its basins. Basins intercepting the main flow and external P sources had highest P and CHL and shallowest SD. Internal loading in shallow, polymictic basins caused P and CHL to increase and SD to decrease as summer progressed. Winter aeration used to eliminate winterkill increased summer internal P loading and decreased water quality, while reductions in upstream beaver impoundments had little effect on water quality. Variations in air temperature and precipitation affected each basin differently. Warmer air temperatures increased productivity throughout the lake and decreased clarity in less eutrophic basins. Increased precipitation increased P in the basins intercepting the main flow but had little effect on the isolated deep West Bay. These relations are used to project effects of future climatic changes on LSG and other temperate lakes.

scholarly journals Climatic-change implications from long-term (1823-1994) ice records for the Laurentian Great Lakes

1995 ◽  
Vol 21 ◽  
pp. 383-386 ◽  
Author(s):  
R.A. Assel ◽  
D.M. Robertson ◽  
M.H. Hoff ◽  
J.H. Selgeby
Keyword(s):  
Great Lakes ◽  
Climatic Changes ◽  
The Other ◽  
Laurentian Great Lakes ◽  
Great Lakes Region ◽  
Lake Mendota ◽  
Air Temperatures ◽  
The 1960S ◽  
Different Parts

Long-term ice records (1823-1994) from six sites in different parts of the Laurentian Great Lakes region were used to show the type and general timing of climatic changes throughout the region. The general timing of both freeze-up and ice loss varies and is driven by local air temperatures, adjacent water bodies and mixing, and site morphometry. Grand Traverse Bay and Buffalo Harbor represent deeper-water environments affected by mixing of off-shore waters; Chequamegon Bay, Menominee, Lake Mendota, and Toronto Harbor represent relatively shallow-water, protected environments. Freeze-up dates gradually became later and ice-loss dates gradually earlier from the start of records to the 1890s in both environments, marking the end of the “Little lce Age”. After this, freeze-up dates remained relatively constant, suggesting little change in early-winter air temperatures during the 20th century. Ice-loss dates at Grand Traverse Bay and Baffalo Harbor but not at the other sites became earlier during the 1940s and 1970s and became later during the 1960s. The global warming of the 1980s was marked by a trend toward earlier ice-loss dates in both environments.

Climate Versus Changes in 13C Content of the Organic Component of Lake Sediments During the Late Quarternary

1975 ◽  
Vol 5 (2) ◽  
pp. 251-262 ◽  
Author(s):  
Minze Stuiver
Keyword(s):  
Lake Sediments ◽  
Climatic Changes ◽  
Organic Component ◽  
Organic Productivity

Several factors influence the long-term 13C record of the organic component in lake sediments. Two of the more predominant ones are changes in hardness of the water and changes in organic productivity. In general, during colder climatic episodes, 13C values are lower. Of 12 lakes studied, 4 have 13C records with large changes in 13C content that are to a certain degree correlative with climatic changes.

Responses of Floods to Holocene Climatic Change in the Upper Mississippi Valley

1985 ◽  
Vol 23 (3) ◽  
pp. 287-300 ◽  
Author(s):  
James C. Knox
Keyword(s):  
Climatic Changes ◽  
Mississippi Valley ◽  
Channel Migration ◽  
Valley Bottom ◽  
Lateral Channel ◽  
History Of ◽  
And Storage ◽  
Recurrence Frequency ◽  
Large Floods

Dimensions of Holocene relict channels and sedimentological characteristics of point bars associated with these relict channels were used to reconstruct a Holocene history of long-term changes in magnitudes of 1.58-yr floods in Upper Mississippi Valley watersheds of southwestern Wisconsin. The reconstructed record of floods shows relatively large and persistent (nonrandom) departures from contemporary long-term average flood magnitudes. The flood history indicates climatic changes that are broadly similar to climatic changes indicated from fossil pollen in the same region. The Holocene floods ranged from about 10–15% larger to 20–30% smaller than contemporary floods of the same recurrence frequency. Large floods were characteristic between about 6000 – 4500 and 3000 – 2000 yr B.P., and during a brief interval after 1200 yr B.P. Small floods were common between about 8000 – 6500, 4500 – 3000, and 2000 – 1200 yr B.P. These fluvial responses were found to be closely associated with a long-term episodic mobility and storage of sediments in the Wisconsin watersheds. During periods of relatively large floods, relatively rapid lateral channel migration either reworked or removed extensive tracts of valley bottom alluvium. In contrast, during periods of relatively small floods, relatively slow lateral channel migration is apparent and the channel and floodplain system appear to have been relatively stable.

Sign in / Sign up

Export Citation Format

Share Document