Long-Term Trends in Prehistoric Fishing and Hunting on Tobago, West Indies

2006 ◽  
Vol 17 (3) ◽  
pp. 316-334 ◽  
Author(s):  
David W. Steadman ◽  
Sharyn Jones
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
West Indies ◽  
Sea Turtles ◽  
Food Preferences ◽  
Reef Fishes ◽  
Archaeological Sites ◽  
Long Term Trends ◽  
The Difference

AbstractWe compare the bone assemblages of Milford 1 (TOB-3) and Golden Grove (TOB-13) in Tobago, West Indies. Milford 1 is a small preceramic occupation (ca. 3000-2800 cal B.P.), whereas Golden Grove is a large ceramic-period village (ca. 1700-900 cal B.P.). Species richness at TOB-13 is greater than at TOB-3, both in marine (67 vs. 39 fishes) and terrestrial (32 vs. 9) taxa. Major shifts in marine exploitation from the preceramic to ceramic periods can be seen in relative abundance of tuna, toadfishes, and in fishes inhabiting mangrove and brackish water environments, and decreases in relative abundance of parrotfish, carnivorous reef fishes, and sea turtles. The abundance of tuna bones at TOB-13 is uniquely high among West Indian archaeological sites. For terrestrial taxa, the difference in species richness exceeds the expected, including decreased specialization on big game (peccaries) at TOB-13, with a greater tendency to hunt reptiles, birds, and mammals of all sizes at TOB-3. Factors underlying the shifts in fishing and hunting may include different collection methods and food preferences of non-Arawakan (preceramic) vs. Arawakan (ceramic) peoples, as well as human-induced declines in populations of peccaries, sea turtles, and selected fish species. Another possible factor is site setting, with the inhabitants of TOB-13 having enhanced access to mangrove habitats.

Long-term trends in abundance of green sea turtles (Chelonia mydas) assessed by non-lethal capture rates in a coastal fishery

2017 ◽  
Vol 79 ◽  
pp. 254-264 ◽  
Author(s):  
Berenice M.G. Silva ◽  
Leandro Bugoni ◽  
Bruno A.D.L. Almeida ◽  
Bruno B. Giffoni ◽  
Fernando S. Alvarenga ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Green Sea Turtles ◽  
Long Term Trends ◽  
Capture Rates

scholarly journals Estimating relative abundance and species richness from video surveys of reef fishes

2014 ◽  
Vol 113 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Nathan M. Bacheler ◽  
Kyle W. Shertzer
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Reef Fishes ◽  
Video Surveys

scholarly journals What is the most efficient and effective method for long-term monitoring of alpine tundra vegetation?

2016 ◽  
Vol 2 (3) ◽  
pp. 127-141 ◽  
Author(s):  
Steven D. Mamet ◽  
Nathan Young ◽  
Kwok P. Chun ◽  
Jill F. Johnstone
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Rare Species ◽  
Alpine Tundra ◽  
The Arctic ◽  
Vegetation Monitoring ◽  
Tundra Vegetation ◽  
Long Term Monitoring ◽  
Term Monitoring

Nondestructive estimations of plant community characteristics are essential to vegetation monitoring programs. However, there is no universally accepted method for this purpose in the Arctic, partly because not all programs share the same logistical constraints and monitoring goals. Our aim was to determine the most efficient and effective method for long-term monitoring of alpine tundra vegetation. To achieve this, we established 12 vegetation-monitoring plots on a south-facing slope in the alpine tundra of southern Yukon Territory, Canada. Four observers assessed these plots for vascular plant species abundance employing three methods: visual cover (VC) and subplot frequency (SF) estimation and modified point-intercept (PI) (includes rare species present but not intersected by a pin). SF performed best in terms of time required per plot and sensitivity to variations in species richness. All methods were similarly poor at estimating relative abundance for rare species, but PI and VC were substantially better at high abundances. Differences among methods were larger than among observers. Our results suggest that SF is best when the monitoring focus is on rare species or species richness across extensive areas. However, when the focus is on monitoring changes in relative abundance of common species, VC or PI should be preferred.

Ecological specialization matters: long-term trends in butterfly species richness and assemblage composition depend on multiple functional traits

2015 ◽  
Vol 21 (7) ◽  
pp. 792-802 ◽  
Author(s):  
Anne Eskildsen ◽  
Luísa G. Carvalheiro ◽  
W. Daniel Kissling ◽  
Jacobus C. Biesmeijer ◽  
Oliver Schweiger ◽  
...  
Keyword(s):  
Species Richness ◽  
Functional Traits ◽  
Butterfly Species ◽  
Ecological Specialization ◽  
Assemblage Composition ◽  
Long Term Trends

scholarly journals Comparing temperature of subauroral mesopause over Yakutia with SABER radiometer data for 2002–2014

2017 ◽  
Vol 3 (2) ◽  
pp. 58-63
Author(s):  
Анастасия Аммосова ◽  
Anastasiya Ammosova ◽  
Галина Гаврильева ◽  
Galina Gavrilyeva ◽  
Петр Аммосов ◽  
...  
Keyword(s):  
Spectral Measurements ◽  
Satellite Measurements ◽  
Mesopause Region ◽  
Temperature Variations ◽  
Broadband Emission ◽  
Long Term Trends ◽  
The Difference ◽  
Temperature Time ◽  
Good Agreement

We present the temperature database for the mesopause region, which was collected from spectral measurements of bands O2(0-1) and OH(6-2) with the infrared spectrograph SP-50 at the Maimaga station (63° N; 129.5° E) in 2002–2014. The temperature time series covers 11-year solar cycle. It is compared with the temperature obtained with the Sounding of the At-mosphere using Broadband Emission Radiometry in-strument (SABER, v.1.07 and v.2.0), installed onboard the TIMED satellite. We compare temperatures meas-ured during satellite passes at distances under 500 km from the intersection of the spectrograph sighting line with the hydroxyl emitting layer (~87 km) and oxygen emitting layer (~95 km). The time criterion is 30 min. We observe that there is a seasonal dependence of the difference between the ground-based and satellite measurements. The data obtained using SABER v2.0 show good agreement with the temperatures measured with the infrared digital spectrograph. The analysis we carried out allows us to conclude that a series of rotational temperatures obtained at the Maimaga station can be used to study temperature variations on different time scales including long-term trends at the mesopause height

Estimating Annual Numbers of Atlantic Hurricanes Missing from the HURDAT Database (1878–1965) Using Ship Track Density

2011 ◽  
Vol 24 (6) ◽  
pp. 1736-1746 ◽  
Author(s):  
Gabriel A. Vecchi ◽  
Thomas R. Knutson
Keyword(s):  
North Atlantic ◽  
Ship Traffic ◽  
Atlantic Hurricane ◽  
Strongly Connected ◽  
Activity Measures ◽  
Long Term Trends ◽  
The Difference ◽  
Atlantic Hurricanes ◽  
The Impact

Abstract This study assesses the impact of imperfect sampling in the presatellite era (between 1878 and 1965) on North Atlantic hurricane activity measures and on the long-term trends in those measures. The results indicate that a substantial upward adjustment of hurricane counts may be needed prior to 1965 to account for likely “missed” hurricanes due to sparse density of reporting ship traffic. After adjusting for the estimate of missed hurricanes in the basin, the long-term (1878–2008) trend in hurricane counts changes from significantly positive to no significant change (with a nominally negative trend). The adjusted hurricane count record is more strongly connected to the difference between main development region (MDR) sea surface temperature (SST) and tropical-mean SST than with MDR SST. These results do not support the hypothesis that the warming of the tropical North Atlantic due to anthropogenic greenhouse gas emissions has caused Atlantic hurricane frequency to increase.

scholarly journals Long-term trends in helminth infections of wood mice (Apodemus sylvaticus) from the vicinity of Malham Tarn in North Yorkshire, England

Parasitology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Jerzy M. Behnke ◽  
Michael T. Rogan ◽  
Philip S. Craig ◽  
Joseph A. Jackson ◽  
Geoff Hide
Keyword(s):  
Species Richness ◽  
Wood Mouse ◽  
Heligmosomoides Polygyrus ◽  
Mouse Population ◽  
Wood Mice ◽  
Higher Taxa ◽  
Helminth Infections ◽  
Underlying Causes ◽  
Long Term Trends

Abstract Helminth infections in wood mice (n = 483), trapped over a period of 26 years in the woods surrounding Malham Tarn in North Yorkshire, were analysed. Although 10 species of helminths were identified, the overall mean species richness was 1.01 species/mouse indicating that the helminth community was relatively depauperate in this wood mouse population. The dominant species was Heligmosomoides polygyrus, the prevalence (64.6%) and abundance (10.4 worms/mouse) of which declined significantly over the study period. Because of the dominance of this species, analyses of higher taxa (combined helminths and combined nematodes) also revealed significantly declining values for prevalence, although not abundance. Helminth species richness (HSR) and Brillouin's index of diversity (BID) did not show covariance with year, neither did those remaining species whose overall prevalence exceeded 5% (Syphacia stroma, Aonchotheca murissylvatici and Plagiorchis muris). Significant age effects were detected for the prevalence and abundance of all higher taxa, H. polygyrus and P. muris, and for HSR and BID, reflecting the accumulation of helminths with increasing host age. Only two cases of sex bias were found; male bias in abundance of P. muris and combined Digenea. We discuss the significance of these results and hypothesize about the underlying causes.

Correction of Inhomogeneities in Observed Land Surface Temperatures over China

2020 ◽  
Vol 33 (20) ◽  
pp. 8885-8902
Author(s):  
Jizeng Du ◽  
Kaicun Wang ◽  
Baoshan Cui ◽  
Shaojing Jiang
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Surface Air Temperature ◽  
Warming Trend ◽  
Cmip5 Models ◽  
Near Surface ◽  
Land Surface Temperatures ◽  
Long Term Trends ◽  
The Difference

AbstractLand surface temperature Ts and near-surface air temperature Ta are two main metrics that reflect climate change. Recently, based on in situ observations, several studies found that Ts warmed much faster than Ta in China, especially after 2000. However, we found abnormal jumps in the Ts time series during 2003–05, mainly caused by the transformation from manual to automatic measurements due to snow cover. We explore the physical mechanism of the differences between automatic and manual observations and develop a model to correct the automatic observations on snowy days in the observed records of Ts. Furthermore, the nonclimatic shifts in the observed Ts were detected and corrected using the RHtest method. After corrections, the warming rates for Ts-max, Ts-min, and Ts-mean were 0.21°, 0.34°, and 0.25°C decade−1, respectively, during the 1960–2014 period. The abnormal jump in the difference between Ts and Ta over China after 2003, which was mentioned in existing studies, was mainly caused by inhomogeneities rather than climate change. Through a combined analysis using reanalyses and CMIP5 models, we found that Ts was consistent with Ta both in terms of interannual variability and long-term trends over China during 1960–2014. The Ts minus Ta (Ts − Ta) trend is from −0.004° to 0.009°C decade−1, accounting for from −3.19% to 5.93% (from −3.09% to 6.39%) of the absolute warming trend of Ts (Ta).

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