Long-Term Trends in Habitat Use of Offshore Demersal Fishes in Western Lake Huron Suggest Large-Scale Ecosystem Change

2010 ◽  
Vol 139 (5) ◽  
pp. 1322-1334 ◽  
Author(s):  
Stephen C. Riley ◽  
Jean V. Adams
Keyword(s):  
Habitat Use ◽  
Large Scale ◽  
Lake Huron ◽  
Ecosystem Change ◽  
Western Lake ◽  
Long Term Trends ◽  
Demersal Fishes

scholarly journals Identifying global synchronies in marine zooplankton populations: issues and opportunities

2004 ◽  
Vol 61 (4) ◽  
pp. 445-456 ◽  
Author(s):  
R.Ian Perry ◽  
Harold P Batchelder ◽  
David L Mackas ◽  
Sanae Chiba ◽  
Edward Durbin ◽  
...  
Keyword(s):  
Large Scale ◽  
International Comparisons ◽  
Data Access ◽  
Ecosystem Change ◽  
Data Sets ◽  
Time Lags ◽  
Structural Constraints ◽  
Spatial And Temporal Scales ◽  
Marine Zooplankton

Abstract Analyses of the influences of climate variability on local zooplankton populations and those within ocean basins are relatively recent (past 5–10 years). What is lacking are comparisons of zooplankton population variability among the world's oceans, in contrast to such global comparisons of fish populations. This article examines the key questions, capabilities, and impediments for global comparisons of zooplankton populations using long-term (>10 year) data sets. The key question is whether global synchronies in zooplankton populations exist. If yes, then (i) to what extent are they driven by “bottom-up” (productivity) or “top-down” (predation) forcing; (ii) are they initiated by persistent forcing or by episodic events whose effects propagate through the system with different time-lags; and (iii) what proportion of the biological variance is caused directly by physical forcing and what proportion might be caused by non-linear instabilities in the biological dynamics (e.g. through trophodynamic links)? The capabilities are improving quickly that will enable global comparisons of zooplankton populations. Several long-term sampling programmes and data sets exist in many ocean basins, and the data are becoming more available. In addition, there has been a major philosophical change recently that now recognizes the value of continuing long-term zooplankton observation programmes. Understanding of life-history characteristics and the ecosystem roles of zooplankton are also improving. A first and critical step in exploring possible synchrony among zooplankton from geographically diverse regions is to recognize the limitations of the various data sets. There exist several impediments that must be surmounted before global comparisons of zooplankton populations can be realized. Methodological issues concerned with the diverse spatial and temporal scales of “monitored” planktonic populations are one example. Other problems include data access issues, structural constraints regarding funding of international comparisons, and lack of understanding by decision-makers of the value of zooplankton as indicators of ecosystem change. We provide recommendations for alleviating some of these impediments, and suggest a need for an easily understood example of global synchrony in zooplankton populations and the relation of those signals to large-scale climate drivers.

Long-term responses of mammalian herbivores to stand thinning and fertilization in young lodgepole pine (Pinus contorta var. latifolia) forest

2010 ◽  
Vol 40 (12) ◽  
pp. 2302-2312 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan ◽  
Pontus M.F. Lindgren ◽  
Douglas B. Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Large Scale ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
South Central ◽  
Commercial Thinning ◽  
Snowshoe Hares ◽  
Understory Shrubs

Snowshoe hares (Lepus americanus Exrleben, 1777), mule deer (Odocoileus hemionus (Rafinesque, 1817)), and moose (Alces alces (L., 1758)) commonly occur in young coniferous forests. This study was designed to test the hypothesis that large-scale pre-commercial thinning (PCT) and repeated fertilization 15–20 years after the onset of treatments in young lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.) stands would enhance relative habitat use by hares, deer, and moose compared with unmanaged stands. Study areas were located in south-central British Columbia, Canada. Habitat use was measured by fecal pellet and pellet-group counts. Understory vegetation and coniferous stand structure were measured in all stands. Habitat use by deer and moose was highest in heavily thinned stands, probably due to the higher levels of forage and cover provided by understory shrubs and conifers in thinned stands. Habitat use by snowshoe hares was highest in high-density stands, but also in lower-density (≤1000 stems·ha–1) stands where an increase in understory conifers provided essential cover for hares. Managers should consider the long-term nature of understory development in young stands managed for timber production. Heavy thinning (≤1000 stems·ha–1) will generate suitable understory habitat for these herbivores sooner than conventional PCT at higher stand densities.

Large-scale, long-term trends in British river macroinvertebrates

2012 ◽  
Vol 18 (7) ◽  
pp. 2184-2194 ◽  
Author(s):  
Ian P. Vaughan ◽  
Steve J. Ormerod
Keyword(s):  
Large Scale ◽  
Long Term Trends

scholarly journals Reply to “Comment on ‘Bias Correction, Quantile Mapping, and Downscaling: Revisiting the Inflation Issue’”

2014 ◽  
Vol 27 (4) ◽  
pp. 1821-1825 ◽  
Author(s):  
Douglas Maraun
Keyword(s):  
Large Scale ◽  
Weather Forecasting ◽  
Small Scale ◽  
Quantile Mapping ◽  
Spatiotemporal Structure ◽  
Weather Forecasts ◽  
Long Term Trends ◽  
Climate Signals ◽  
Local Variability

Abstract In his comment, G. Bürger criticizes the conclusion that inflation of trends by quantile mapping is an adverse effect. He assumes that the argument would be “based on the belief that long-term trends and along with them future climate signals are to be large scale.” His line of argument reverts to the so-called inflated regression. Here it is shown, by referring to previous critiques of inflation and standard literature in statistical modeling as well as weather forecasting, that inflation is built upon a wrong understanding of explained versus unexplained variability and prediction versus simulation. It is argued that a sound regression-based downscaling can in principle introduce systematic local variability in long-term trends, but inflation systematically deteriorates the representation of trends. Furthermore, it is demonstrated that inflation by construction deteriorates weather forecasts and is not able to correctly simulate small-scale spatiotemporal structure.

scholarly journals Long-term trends in the foraging ecology and habitat use of an endangered species: an isotopic perspective

Oecologia ◽  
2018 ◽  
Vol 188 (4) ◽  
pp. 1273-1285 ◽  
Author(s):  
Elizabeth D. Hetherington ◽  
Jeffrey A. Seminoff ◽  
Peter H. Dutton ◽  
Lisa C. Robison ◽  
Brian N. Popp ◽  
...  
Keyword(s):  
Endangered Species ◽  
Habitat Use ◽  
Foraging Ecology ◽  
Long Term Trends

scholarly journals Central-Eastern China Persistent Heat Waves: Evaluation of the AMIP Models

2018 ◽  
Vol 31 (9) ◽  
pp. 3609-3624 ◽  
Author(s):  
N. Freychet ◽  
S. F. B. Tett ◽  
G. C. Hegerl ◽  
J. Wang
Keyword(s):  
Heat Wave ◽  
Large Scale ◽  
Heat Waves ◽  
Eastern China ◽  
Ground Station ◽  
Significant Difference ◽  
Long Term Trends ◽  
Central Eastern ◽  
Seasonal Signal

Abstract Large-scale and persistent heat waves affecting central-eastern China are investigated in 40 different simulations of sea surface temperature driven global atmospheric models. The different models are compared with results from reanalysis and ground station datasets. It is found that the dynamics of heat-wave events is well reproduced by the models. However, they tend to produce too-persistent heat-wave events (lasting more than 20 days), and several hypotheses were tested to explain this bias. The daily variability of the temperatures or the seasonal signal did not explain the persistence. However, interannual variability of the temperatures in the models, and especially the sharp transition in the mid-1990s, has a large impact on the duration of heat waves. A filtering method was applied to select the models closest to the observations in terms of events persistence. The selected models do not show a significant difference from the other models for the long-term trends. Thus, the bias on the duration of the events does not impact the reliability of the model positive trends, which is mainly controlled by the changes in mean temperatures.

scholarly journals Landfalling Tropical Cyclones along the Eastern Pacific Coast between the Sixteenth and Twentieth Centuries

2013 ◽  
Vol 26 (12) ◽  
pp. 4219-4230 ◽  
Author(s):  
Marni Pazos ◽  
Blanca Mendoza
Keyword(s):  
Tropical Cyclones ◽  
Large Scale ◽  
Pacific Coast ◽  
Eastern Pacific ◽  
Historical Time ◽  
Eastern Pacific Ocean ◽  
Mexican Pacific ◽  
Long Term Trends ◽  
Landfalling Tropical Cyclones

Abstract Numerous studies have been conducted to document long-term trends in tropical cyclone (TC) activity. However, the eastern Pacific has not received as much attention as other basins. Here the authors attempt the identification of TC formation in the Mexican eastern Pacific Ocean before 1950. Using bibliographical and historical file consultation, they constructed a catalog of events related to intense storms and possible TCs that made landfall on the Mexican Pacific coasts. Between 1536 and 1948 they found a total of 119 events related to TCs. Then, using the Saffir–Simpson scale and the climatology of the region as the criteria to evaluate each event, they found 85 TCs. Furthermore, they constructed a historical time series of TCs between 1701 and 2010. The spectral analysis showed periodicities of ~2.6, 4, 5, 12, 16, 39, and 105 years that coincide with some large-scale climatic phenomena and also with solar activity. In particular, the ~12-yr cycle is the most persistent periodicity in this study.

Opposite trends of sea-breeze speeds and gusts in Eastern Iberian Peninsula, 1961-2019

2021 ◽  
Author(s):  
Shalenys Bedoya-Valestt ◽  
Cesar Azorin-Molina ◽  
José A. Guijarro ◽  
Victor J. Sanchez-Morcillo
Keyword(s):  
Wind Speed ◽  
Iberian Peninsula ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Sea Breeze ◽  
Sea Breezes ◽  
Long Term Trends ◽  
Large Scale Atmospheric Circulation

<p>Long-term trends of local winds such as sea breezes have been less addressed in climate research, despite their impacts on broad environmental and socioeconomic spheres, such as weather and climate, agriculture and hydrology, wind-power industry, air quality or even human health, among many others. In a warming climate, sea breezes could be affected by changes on air temperature, as these onshore winds are thermally-driven by gradients between the sea-land air, but also by ocean-atmosphere oscillations or changes in large-scale atmospheric circulation. In the last few decades, advances in wind trends studies evidenced a recovery in global wind stilling during the last 10 years, and differences in the sign-magnitude of wind speed trends were found at seasonal-scale, suggesting the hypothetic effect of the reinforcement of local wind circulations in the warm seasons.</p><p>In this study, we analyze for the first time the long-term trends, multidecadal variability and possible drivers of the sea-breeze speeds and gusts in Eastern Iberian Peninsula during the last 58 years (1961-2019), using homogenized wind speed and gusts data from 16 meteorological stations. To identify potential sea breeze episodes, we developed a robust automated method based on alternative criteria. Our results suggest a decoupling between the declining sea-breeze speeds and the strengthening of the maximum gusts for much of the 1961-2019 period at annual, seasonal and monthly scales, but differences based on locations were also found. Because sea breeze changes can be driven by multiple complex factors (i.e. land use changes, land-sea air temperature gradient, complex orography, etc.), the attribution of causes is challenging. To better understand the causes behind the opposite trends between sea-breeze speeds and gusts, we investigate the effect of e.g. the changes in large-scale atmospheric circulation or physical-local factors.</p>

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