Climatic change caused larger variation of spring phenology in temperate semi-dry grasslands in China

2020 ◽  
Author(s):  
Xuancheng Zhou ◽  
Yongshuo Fu ◽  
Yaru Zhang
Keyword(s):  
Limiting Factor ◽  
Entire Study Period ◽  
Temperate Grasslands ◽  
Spring Phenology ◽  
Entire Study ◽  
Dry Grassland ◽  
Dry Grasslands ◽  
Temperature And Precipitation ◽  
Highly Sensitive ◽  
Climatic Drivers

<p>Vegetation phenology is highly sensitive to climate change. Previous studies focusing on the trends of phenological events have found that temperature and precipitation primarily regulate the dates of spring phenology in temperate grasslands. However, the variation of spring phenology and its controlling factors are still unclear. In this study, we investigated the start of the growing season (SOS) in temperate semi-dry grasslands in China using five methods, and determined the variation of SOS and its primary factor over the study period 1982-2015. We found that, in line with previous studies, the SOS date did not change significantly during the entire study period 1982-2015, but its variation increased significantly from the first subperiod (1982-1998, Std: 8.8±1.1 day) to the second (1999-2015, Std: 10.3±1.1 days), the latter of which coincides with fast warming. The larger variation in SOS may be caused by the different climatic drivers on phenology in different areas. The fluctuation of temperature was significantly increased over the study area and subsequently may result in a larger variation of SOS. Furthermore, precipitation and soil moisture has increased until the mid-1990s, which may lead to the removal of water as a limiting factor and increase the response of semi-dry grassland spring phenology to temperature, and finally result in larger variation in SOS.</p>

scholarly journals Mapping Spatiotemporal Changes in Vegetation Growth Peak and the Response to Climate and Spring Phenology over Northeast China

2020 ◽  
Vol 12 (23) ◽  
pp. 3977
Author(s):  
Xiaoying Wang ◽  
Yuke Zhou ◽  
Rihong Wen ◽  
Chenghu Zhou ◽  
Lili Xu ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Northeast China ◽  
Climatic Factors ◽  
Spring Phenology ◽  
Entire Study ◽  
Vegetation Growth ◽  
Temperature And Precipitation ◽  
Spatiotemporal Changes ◽  
Vegetation Production

Global climate change has led to significant changes in seasonal rhythm events of vegetation growth, such as spring onset and autumn senescence. Spatiotemporal shifts in these vegetation phenological metrics have been widely reported over the globe. Vegetation growth peak represents plant photosynthesis capacity and responds to climate change. At present, spatiotemporal changes in vegetation growth peak characteristics (timing and maximum growth magnitude) and their underlying governing mechanisms remain unclear at regional scales. In this study, the spatiotemporal dynamics of vegetation growth peak in northeast China (NEC) was investigated using long-term NDVI time series. Then, the effects of climatic factors and spring phenology on vegetation growth peak were examined. Finally, the contribution of growth peak to vegetation production variability was estimated. The results of the phenological analysis indicate that the date of vegetation green up in spring and growth peak in summer generally present a delayed trend, while the amplitude of growth peak shows an increasing trend. There is an underlying cycle of 11 years in the vegetation growth peak of the entire study area. Air temperature and precipitation before the growing season have a small impact on vegetation growth peak amplitude both in its spatial extent and magnitude (mainly over grasslands) but have a significant influence on the date of the growth peak in the forests of the northern area. Spring green-up onset has a more significant impact on growth peak than air temperature and precipitation. Although green-up date plays a more pronounced role in controlling the amplitude of the growth peak in forests and grasslands, it also affects the date of growth peak in croplands. The amplitude of the growth peak has a significant effect on the inter-annual variability of vegetation production. The discrepant patterns of growth peak response to climate and phenology reflect the distinct adaptability of the vegetation growth peak to climate change, and result in different carbon sink patterns over the study area. The study of growth peak could improve our understanding of vegetation photosynthesis activity over various land covers and its contribution to carbon uptake.

Population biology and diet of the puffer fish Lagocephalus laevigatus (Tetraodontiformes: Tetraodontidae) in Caraguatatuba Bay, south-eastern Brazil

2011 ◽  
Vol 92 (2) ◽  
pp. 407-412 ◽  
Author(s):  
M.R. Denadai ◽  
F.B. Santos ◽  
E. Bessa ◽  
L.P. Bernardes ◽  
A. Turra
Keyword(s):  
Population Biology ◽  
Temporal Distribution ◽  
Late Winter ◽  
Entire Study Period ◽  
Entire Study ◽  
South Eastern ◽  
Eastern Brazil ◽  
Puffer Fish ◽  
Spatio Temporal ◽  
Sexually Mature

This study describes the spatio-temporal distribution, population biology, and diet of the puffer fish Lagocephalus laevigatus in Caraguatatuba Bay, south-eastern Brazil. Monthly samples were taken between August 2003 and October 2004 by trawls in two areas, south and north, at depths of 1 to 4 m. The fish were measured and their sex and reproductive stage determined. The abundance of this species was compared between areas and among months, and the items in the diet were identified and quantified. Lagocephalus laevigatus was rare in Caraguatatuba Bay, where only 199 small individuals (4.8 to 15.4 cm) were obtained in the entire study period, suggesting that this species uses the estuary as a nursery. None of the specimens of L. laevigatus captured in Caraguatatuba Bay were sexually mature. Higher densities of L. laevigatus in the bay were recorded in the south area and between October and December 2003, i.e. in the spring, suggesting that spawning may occur from late winter to spring (August through to November). The diet items consumed by L. laevigatus in Caraguatatuba Bay were, as expected from the current literature, crustaceans, mainly amphipods, and fish. However, the most-consumed item was the sea whip Leptogorgia setacea (Cnidaria). This feeding habit may be related to the presence of toxins (tetrodotoxin and saxitoxin) that are frequently found in the skin and viscera of L. laevigatus, which may be sequestered from the sea whip, which possibility still needs to be specifically evaluated.

scholarly journals Terrestrial Molluscs in the Dry Grasslands of the DNIPRO Upland (Central Ukraine): New Records, Rare Species and Conservation Potential

2018 ◽  
Vol 52 (1) ◽  
pp. 3-12 ◽  
Author(s):  
I. Balashov ◽  
O. Vasyliuk ◽  
D. Shyriaieva ◽  
Z. Shvydka ◽  
O. Oskyrko ◽  
...  
Keyword(s):  
Rare Species ◽  
New Records ◽  
National Level ◽  
Red List ◽  
The Other ◽  
Rock Outcrops ◽  
Dry Grassland ◽  
Dry Grasslands ◽  
First Time ◽  
High Diversity

Abstract Thirty-six species of terrestrial molluscs were found in the dry grasslands and rock outcrops of the study area, including three that were not previously known for Central Ukraine: Granaria frumentum, Pupilla bigranata and Mediterranea inopinata. These species are relics related to dry open habitats and require conservation in Ukraine on the national level, G. frumentum is already listed in the Red Book of Ukraine, and the other two should be listed in its next edition. It is proposed to create the new protected areas in the most important newly revealed locations of these species. These rocky areas also retain the high diversity of land molluscs in the region. The invasive snail Xeropicta derbentina was found for the first time on the DNIPRO Upland, on the edge of natural dry grassland. The rare native snail Morlina glabra was recorded for the first time in Kyiv Region, it is proposed to be included into the regional red list.

scholarly journals Prevalence of the nematodes Eustrongylides exisus Jägerskiöld, 1909, – larvae (Nematoda: Dioctophymatidae) infection in the Rutilis rutilis, linnaeus 1758 and the seasonal dynamics of the infection in the waters of the Dnipro-Buh estuari in southern Ukrai

2020 ◽  
Vol 22 (97) ◽  
pp. 31-38
Author(s):  
S. L. Honcharov
Keyword(s):  
Entire Study Period ◽  
Sample Collection ◽  
Upward Trend ◽  
Entire Study ◽  
Total Prevalence ◽  
The Mean ◽  
Predatory Fishes ◽  
Two Peaks ◽  
The Village ◽  
Collection Sites

In this study, we determined the prevalence and seasonal dynamic of the infection of the Rutilis rutilis, Lіnnaeus 1758 with the nematode Eustrongylides excisus. The fish was caught in the waters of the Dnipro-Buh estuary in seven sample collection sites between 2016 and 2019. They all underwent ichthyopathological examination. Parasites, found during examination, undergone microscopy to determine their taxonomy. Overall 595 specimens were obtained. The mean prevalence of infection over entire study period (2016–2019) was 17.4 %. Ichthyopathological examination of the roach caught in the waters of the Dnipro-Buh estuary revealed the infection with larvae E. excises nematode. The parasitic larvae were found in the muscles of the ventral abdominal wall of the roach. There was more than two-fold difference in the prevalence of infection between sample collection sites – from 12 % in site 5 near Sofiivka to 28 % in site 3 near the village Oleksandrivka over the study period in 2016–2019. The total prevalence of infection in roaches in the Dnipro-Buh estuary was 17.4 %. Seasonal changes were not statistically significant and ranged from 12.8 % in summer to 20.1 % in spring. Annual changes suggested a possible upward trend, but more observations are needed to confirm it. Аnnual changes were not statistically significant. The prevalence of infection changed throughout the year: there were two peaks in spring (20.1 %) and autumn (18.3 %). In summer (12.8 %) and winter (15.1 %) the prevalence of infection was lower. Morphologically, the E. excisus larvae found in roaches were different compared to those found in predatory fishes: they had more pale color and were smaller in length. E. excisus is a prevalent infection of roach in Dnipro-Buh estuary. Considering seemingly increasing prevalence of E.excisus infection, further studies are required to understand a pathophysiology of E.excisus infection  in mammals and humans, since data remain limited.

Analysis of extreme rains through climate indicators in the context of climate change in southern Benin

2021 ◽  
Vol 2 (1b) ◽  
pp. C20A01-1-C20A01-33
Author(s):  
Ferdinand Sourou HOUNVOU ◽  
◽  
K. F. Guedje ◽  
Hilaire Kougbeagbede ◽  
Adebiyi Joseph Adechinan ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
West Africa ◽  
Economic System ◽  
Entire Study Period ◽  
Entire Study ◽  
Climate Indicators ◽  
Large Growth ◽  
Southern Benin ◽  
Heavy Rains

The recurrence of flooding in recent years in West Africa is dramatically affecting the socio-economic system of most countries in the region. This work is devoted to the analysis of the heavy rains of its last years in the context of global warming in subequatorial Benin through eight rainfall indicators. For this purpose, the daily rains collected at seventeen stations in the south of Benin between 1960 and 2018, the maximum and minimum daily temperatures of the two synoptic stations in the study area between 1970 and 2018 are used. Analysis of the results shows a non-uniform trend in rainfall indicators over the entire study period. The monthly trend is in accordance with the bimodal rain regime of southern Benin for each of the climatic indicators studied. After the break in the downward trend in rainfall in the 1980s or 1990s at the various stations, the last three decades have been marked above all by ten-year averages of the various indicators that are higher than those obtained over the entire study period. Despite the low proportion of extreme rains, their frequency has increased since the resumption of rainfall in the 1980s or 1990s, especially compared to the 1970s and 1980s. The highest heights are observed for the most part in the towns close to the sea Atlantic Ocean. Global warming in southern Benin is characterized above all by high decadal temperature variation rates in the 1990s. This significant global warming in this pivotal decade is accompanied by relatively large growth in all indicators in southern Benin.

scholarly journals Biological contamination of soils in urbanized ecosystems by Toxocara sp. eggs.

2020 ◽  
Vol 169 ◽  
pp. 04002
Author(s):  
Olga Maslennikova ◽  
Viktoriya Erofeeva
Keyword(s):  
Average Rate ◽  
50Th Anniversary ◽  
Entire Study Period ◽  
Entire Study ◽  
Fecal Samples ◽  
Biological Contamination ◽  
Dog Walking ◽  
Special Area ◽  
Contamination Of Soils ◽  
Study Sites

As a result of the study of three sites (two city parks and a special area for walking dogs) on the contamination of Toxocara sp. eggs it was found that 28.0±2.3% of the studied fecal samples from the territories of the Kirov Park were infected with Тохосаrа eggs, 21.0±3.6% of fecal samples from the territory of the Park of the 50th anniversary of the Komsomol and 7.0±0.4% of fecal samples were infected with Тохосаrа eggs selected at a specially equipped dog walking area in the Metrograd residential complex in Kirov. The average rate of dogs which were infected by Toxocara (EI) was 18.7±6.2%. The average rate of contamination of soil by eggs Тохосаrа in the study sites amounted to 34.6%. Contamination of soil samples with eggs of Toxocara sp. in parks was 45.6% and 45.8%, respectively, and in the dog walking area it was 12%. The largest number of dogs, including stray ones, were registered in the parks: 74.8±7.1 and 62.8±7.0 individuals, respectively. There were no stray individuals in the dog walking area, and there were 21.6±1.0 individuals over the entire study period.

scholarly journals Locating Seismo-Conductivity Anomaly before the 2017 MW 6.5 Jiuzhaigou Earthquake in China Using Far Magnetic Stations

2020 ◽  
Vol 12 (11) ◽  
pp. 1777
Author(s):  
Zhiqiang Mao ◽  
Chieh-Hung Chen ◽  
Suqin Zhang ◽  
Aisa Yisimayili ◽  
Huaizhong Yu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Moving Window ◽  
Entire Study Period ◽  
Conductivity Anomaly ◽  
Promising Candidate ◽  
Jiuzhaigou Earthquake ◽  
Entire Study ◽  
Background Distribution ◽  
Geomagnetic Data ◽  
Magnetic Transfer

Changes in the underlying conductivity around hypocenters are generally considered one of the promising mechanisms of seismo-electromagnetic anomaly generation. Parkinson vectors are indicators of high-conductivity materials and were utilized to remotely monitor conductivity changes during the MW 6.5 Jiuzhaigou earthquake (103.82°E, 33.20°N) on 8 August 2017. Three-component geomagnetic data recorded in 2017 at nine magnetic stations with epicenter distances of 63–770 km were utilized to compute the azimuths of the Parkinson vectors based on the magnetic transfer function. The monitoring and background distributions at each station were constructed by using the azimuths within a 15-day moving window and over the entire study period, respectively. The background distribution was subtracted from the monitoring distribution to mitigate the effects of underlying inhomogeneous electric conductivity structures. The differences obtained at nine stations were superimposed and the intersection of a seismo-conductivity anomaly was located about 70 km away from the epicenter about 17 days before the earthquake. The anomaly disappeared about 7 days before and remained insignificant after the earthquake. Analytical results suggested that the underlying conductivity close to the hypocenter changed before the Jiuzhaigou earthquake. These changes can be detected simultaneously by using multiple magnetometers located far from the epicenter. The disappearance of the seismo-conductivity anomaly after the earthquake sheds light on a promising candidate of the pre-earthquake anomalous phenomena.

Evaluation of dosing and safety outcomes of low-dose prophylactic warfarin in children after cardiothoracic surgery

2020 ◽  
Vol 77 (13) ◽  
pp. 1018-1025
Author(s):  
Maura Harkin ◽  
Brittany Powers Shaddix ◽  
Stephen B Neely ◽  
Leigh A Peek ◽  
Katy Stephens ◽  
...  
Keyword(s):  
Low Dose ◽  
Warfarin Dose ◽  
International Normalized Ratio ◽  
Primary Objective ◽  
Cardiothoracic Surgery ◽  
Entire Study Period ◽  
Entire Study ◽  
Frequent Monitoring ◽  
Safety Outcomes ◽  
Warfarin Dosing

Abstract Purpose Prophylactic warfarin with an International Normalized Ratio (INR) goal of 1.5 to 2.0 is one antithrombotic therapy utilized in children after cardiothoracic surgery (CTS); published sources suggest a dose of 0.1 mg/kg per day to achieve this goal. However, few studies have evaluated dosing in this population. The purpose of this study was to evaluate dosing and safety outcomes in children receiving warfarin after CTS. Methods A descriptive, retrospective review was conducted to evaluate warfarin dosing and INR outcomes in patients 18 years of age or younger who underwent CTS and received prophylactic warfarin with an INR goal of 1.5 to 2.0 from January 2014 through December 2018. The primary objective was to determine the median initial warfarin dose. Secondary objectives included identifying the percentage of documented INR values that were outside the therapeutic range, the percentage of patients with therapeutic INRs at discharge, and the 30-day readmission rate. Results Twenty-six patients were included in the review. The median initial warfarin dosage was 0.07 mg/kg/d (interquartile range [IQR], 0.05-0.10 mg/kg/d). Of the total of 177 INR values collected during the entire study period, 67 (37.9%) were therapeutic, 64 (36.2%) were subtherapeutic, and 46 (26.0%) were supratherapeutic. Eighteen patients (69.2%) had at least 1 supratherapeutic INR at any point during the study period, most frequently on days 2 through 4 of therapy. At discharge, 11 patients (42.3%) had therapeutic INRs. Four patients (15.4%) were readmitted within 30 days, with bleeding documented in 2 patients during their readmission. Conclusion The majority of patients received an initial warfarin dose less than that specified in published recommendations but still had a supratherapeutic INR at least once during the study period. When initiating warfarin after CTS, a dosage of <0.1 mg/kg per day and frequent monitoring may be needed to achieve an INR goal of 1.5 to 2.0.

Characterizing the first wave of fish and invertebrate colonization on a new offshore petroleum platform

2019 ◽  
Vol 77 (3) ◽  
pp. 1127-1136 ◽  
Author(s):  
Victoria L G Todd ◽  
Laura D Williamson ◽  
Sophie E Cox ◽  
Ian B Todd ◽  
Peter I Macreadie
Keyword(s):  
Artificial Reef ◽  
Minimal Change ◽  
Entire Study Period ◽  
Survey Period ◽  
Entire Study ◽  
Ecological Connectivity ◽  
Marine Communities ◽  
Offshore Oil ◽  
Invertebrate Colonization ◽  
Insight Into

Abstract Offshore Oil & Gas (O&G) infrastructure creates artificial reef complexes that support marine communities in oceans. No studies have characterized the first wave of colonization, which can reveal information about habitat attraction and ecological connectivity. Here we used opportunistically-collected industrial Remotely Operated Vehicles (ROVs) to investigate fish and invertebrate colonization on a new North Sea O&G platform and trenching of an associated pipeline. We observed rapid colonization of fish communities, with increases in species richness (S), abundance (N), and diversity (H′) over the first four days (the entire study period). By contrast, there was minimal change in motile invertebrate communities over the survey period. After trenching, invertebrate S, N and H′ decreased significantly, whilst fish S, N and H′ increased. This study is the first to report on the pioneer wave of fish and invertebrate colonization on O&G infrastructure, thereby providing rare insight into formation of new reef communities in the sea. These short and opportunistic data are valuable in terms of showing what can be discovered from analysis of ‘pre-installation’ ROV footage of O&G structures, of which there are terabytes of data held by O&G companies waiting to be analyzed by environmental scientists.

scholarly journals Tree-Ring Width and Carbon Isotope Chronologies Track Temperature, Humidity, and Baseflow in the Tianshan Mountains, Central Asia

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1308
Author(s):  
Yuting Fan ◽  
Huaming Shang ◽  
Ye Wu ◽  
Qian Li
Keyword(s):  
Stable Isotopes ◽  
Tree Ring ◽  
Ring Width ◽  
River Basins ◽  
Tianshan Mountains ◽  
Limiting Factor ◽  
Source Water ◽  
Tree Ring Width ◽  
The North ◽  
Temperature And Precipitation

Concerns have been raised about the negative impacts of global warming on the hydrological climate change and ecosystems of Asia. Research on the high-altitude mountainous regions of Asia with relatively short meteorological and hydrological records relies on paleoclimate proxy data with long time scales. The stable isotopes of tree-rings are insightful agents that provide information on pre-instrumental climatic and hydrological fluctuations, yet the variability of these data from different regions along the Tianshan Mountains has not been fully explored. Herein, we related climate data with tree-ring width (TRW) chronologies and δ13C (stable carbon isotope discrimination) series to discern if the Picea schrenkiana in the Ili and Manas River Basins are sensitive to climatic factors and baseflow (BF). The results show significant correlations between temperature and TRW chronologies, temperature and δ13C, relative humidity and TRW chronologies, and BF and δ13C. Temperature, particularly the mean late summer to early winter temperature, is a pronounced limiting factor for the tree-ring and the δ13C series in the Manas River Basin, located in the middle of the North Tianshan Mountains. Meanwhile, mean early spring to early autumn temperature is a limiting factor for that of the Ili River Basin, located on the southern slope of the North Tianshan Mountains. We conclude that different seasonal variations in temperature and precipitation of the two river basins exerted significant control on tree growth dynamics. Tree-ring width and tree-ring δ13C differ in their sensitivity to climate and hydrological parameters to which tree-ring δ13C is more sensitive. δ13C showed significant lag with precipitation, and the lag correlation showed that BF, temperature, and precipitation were the most affected factors that are often associated with source water environments. δ13C series correlated positively to winter precipitation, suggesting baseflow was controlling the length of the growing season. The tree-ring δ13C provided information that coincided with TRW chronologies, and supplied some indications that were different from TRW chronologies. The carbon stable isotopes of tree-rings have proven to be powerful evidence of climatic signals and source water variations.

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