Correlates of Annual Stopover Counts in Two Species of Arctic-Breeding Shorebirds: Roles of Local, Breeding, and Climatic Drivers

Waterbirds ◽  
2021 ◽  
Vol 44 (1) ◽  
Author(s):  
David D. Hope ◽  
Anna Drake ◽  
Daniel Shervill ◽  
Moira J. F. Lemon ◽  
Mark C. Drever
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
David Canal ◽  
Lotte Schlicht ◽  
Simone Santoro ◽  
Carlos Camacho ◽  
Jesús Martínez-Padilla ◽  
...  

AbstractWhy females engage in social polygyny remains an unresolved question in species where the resources provided by males maximize female fitness. In these systems, the ability of males to access several females, as well as the willingness of females to mate with an already mated male, and the benefits of this choice, may be constrained by the socio-ecological factors experienced at the local scale. Here, we used a 19-year dataset from an individual-monitored population of pied flycatchers (Ficedula hypoleuca) to establish local networks of breeding pairs. Then, we examined whether the probability of becoming socially polygynous and of mating with an already mated male (thus becoming a secondary female) is influenced by morphological and sexual traits as proxies of individual quality relative to the neighbours. We also evaluated whether social polygyny is adaptive for females by examining the effect of females’ mating status (polygamously-mated vs monogamously-mated) on direct (number of recruits in a given season) and indirect (lifetime number of fledglings produced by these recruits) fitness benefits. The phenotypic quality of individuals, by influencing their breeding asynchrony relative to their neighbours, mediated the probability of being involved in a polygynous event. Individuals in middle-age (2–3 years), with large wings and, in the case of males, with conspicuous sexual traits, started to breed earlier than their neighbours. By breeding locally early, males increased their chances of becoming polygynous, while females reduced their chances of mating with an already mated male. Our results suggest that secondary females may compensate the fitness costs, if any, of sharing a mate, since their number of descendants did not differ from monogamous females. We emphasize the need of accounting for local breeding settings (ecological, social, spatial, and temporal) and the phenotypic composition of neighbours to understand individual mating decisions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
James R. Thomson ◽  
Philip B. Holden ◽  
Pallavi Anand ◽  
Neil R. Edwards ◽  
Cécile A. Porchier ◽  
...  

AbstractAsian Monsoon rainfall supports the livelihood of billions of people, yet the relative importance of different drivers remains an issue of great debate. Here, we present 30 million-year model-based reconstructions of Indian summer monsoon and South East Asian monsoon rainfall at millennial resolution. We show that precession is the dominant direct driver of orbital variability, although variability on obliquity timescales is driven through the ice sheets. Orographic development dominated the evolution of the South East Asian monsoon, but Indian summer monsoon evolution involved a complex mix of contributions from orography (39%), precession (25%), atmospheric CO2 (21%), ice-sheet state (5%) and ocean gateways (5%). Prior to 15 Ma, the Indian summer monsoon was broadly stable, albeit with substantial orbital variability. From 15 Ma to 5 Ma, strengthening was driven by a combination of orography and glaciation, while closure of the Panama gateway provided the prerequisite for the modern Indian summer monsoon state through a strengthened Atlantic meridional overturning circulation.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 179
Author(s):  
Roxanne Ahmed ◽  
Terry Prowse ◽  
Yonas Dibike ◽  
Barrie Bonsal

Spring freshet is the dominant annual discharge event in all major Arctic draining rivers with large contributions to freshwater inflow to the Arctic Ocean. Research has shown that the total freshwater influx to the Arctic Ocean has been increasing, while at the same time, the rate of change in the Arctic climate is significantly higher than in other parts of the globe. This study assesses the large-scale atmospheric and surface climatic conditions affecting the magnitude, timing and regional variability of the spring freshets by analyzing historic daily discharges from sub-basins within the four largest Arctic-draining watersheds (Mackenzie, Ob, Lena and Yenisei). Results reveal that climatic variations closely match the observed regional trends of increasing cold-season flows and earlier freshets. Flow regulation appears to suppress the effects of climatic drivers on freshet volume but does not have a significant impact on peak freshet magnitude or timing measures. Spring freshet characteristics are also influenced by El Niño-Southern Oscillation, the Pacific Decadal Oscillation, the Arctic Oscillation and the North Atlantic Oscillation, particularly in their positive phases. The majority of significant relationships are found in unregulated stations. This study provides a key insight into the climatic drivers of observed trends in freshet characteristics, whilst clarifying the effects of regulation versus climate at the sub-basin scale.


Author(s):  
Liudmila Mukhortova ◽  
Dmitry Schepaschenko ◽  
Elena Moltchanova ◽  
Anatoly Shvidenko ◽  
Nikolay Khabarov ◽  
...  

2018 ◽  
Vol 48 (9) ◽  
pp. 1108-1113 ◽  
Author(s):  
Gabriel Sangüesa-Barreda ◽  
J. Julio Camarero ◽  
Jan Esper ◽  
J. Diego Galván ◽  
Ulf Büntgen

Long-term fluctuations in forest recruitment, at time scales well beyond the life-span of individual trees, can be related to climate changes. The underlying climatic drivers are, however, often understudied. Here, we present the recruitment history of a high-elevation mountain pine (Pinus uncinata Ram.) forest in the Spanish central Pyrenees throughout the last millennium. A total of 1108 ring-width series translated into a continuous chronology from 924 to 2014 CE, which allowed estimated germination dates of 470 trees to be compared against decadal-scale temperature variability. High recruitment intensity mainly coincided with relatively warm periods in the early 14th, 15th, 19th, and 20th centuries, whereas cold phases during the mid-17th, early 18th, and mid-19th centuries overlapped with generally low recruitment rates. In revealing the importance of prolonged warm conditions for high-elevation pine recruitment in the Pyrenees, this study suggests increased densification and even possible upward migration of tree-line ecotones under predicted global warming.


Author(s):  
Marcela Serna‐González ◽  
Ligia E. Urrego‐Giraldo ◽  
Juan P. Santa‐Ceballos ◽  
Hiroshi Suzuki‐Azuma

2021 ◽  
Author(s):  
Rebecca Wright ◽  
Corinne Le Quéré ◽  
Erik Buitenhuis ◽  
Dorothee Bakker

<p>The Southern Ocean plays an important role in the uptake, transport and storage of carbon by the global oceans. These properties are dominated by the response to the rise in anthropogenic CO<sub>2</sub> in the atmosphere, but they are modulated by climate variability and climate change. Here we explore the effect of climate variability and climate change on ocean carbon uptake and storage in the Southern Ocean. We assess the extent to which climate change may be distinguishable from the anthropogenic CO<sub>2</sub> signal and from the natural background variability. We use a combination of biogeochemical ocean modelling and observations from the GLODAPv2020 database to detect climate fingerprints in dissolved inorganic carbon (DIC).</p><p>We conduct an ensemble of hindcast model simulations of the period 1920-2019, using a global ocean biogeochemical model which incorporates plankton ecosystem dynamics based on twelve plankton functional types. We use the model ensemble to isolate the changes in DIC due to rising anthropogenic CO<sub>2</sub> alone and the changes due to climatic drivers (both climate variability and climate change), to determine their relative roles in the emerging total DIC trends and patterns. We analyse these DIC trends for a climate fingerprint over the past four decades, across spatial scales from the Southern Ocean, to basin level and down to regional ship transects. Highly sampled ship transects were extracted from GLODAPv2020 to obtain locations with the maximum spatiotemporal coverage, to reduce the inherent biases in patchy observational data. Model results were sampled to the ship transects to compare the climate fingerprints directly to the observational data.</p><p>Model results show a substantial change in DIC over a 35-year period, with a range of more than +/- 30 µmol/L. In the surface ocean, both anthropogenic CO<sub>2</sub> and climatic drivers act to increase DIC concentration, with the influence of anthropogenic CO<sub>2</sub> dominating at lower latitudes and the influence of climatic drivers dominating at higher latitudes. In the deep ocean, the anthropogenic CO<sub>2</sub> generally acts to increase DIC except in the subsurface waters at lower latitudes, while climatic drivers act to decrease DIC concentration. The combined fingerprint of anthropogenic CO<sub>2</sub> and climatic drivers on DIC concentration is for an increasing trend at the surface and decreasing trends in low latitude subsurface waters. Preliminary comparison of the model fingerprints to observational ship transects will also be presented.</p>


Nematology ◽  
2021 ◽  
pp. 1-13
Author(s):  
Minghui Huang ◽  
Ruifeng Qin ◽  
Chunjie Li ◽  
Mingze Wang ◽  
Ye Jiang ◽  
...  

Summary Soybean cyst nematode (SCN, Heterodera glycines) is a devastating plant-parasitic nematode worldwide. Two SCN races, race 4 (HG Type 1.2.3.5.6.7) and race 5 (HG Type 2.5.7), with increased virulence were previously identified in Northeast China. To obtain new resistance sources to these SCN populations, the response of 62 genotypes, including 51 local varieties and breeding lines, and 11 indicator lines for SCN race and HG Type identification, were evaluated. Four new primers in the regions of two loci of GmSHMT08 (Rhg4) and GmSNAP18 (rhg1) were designed for PCR amplification and subsequent sequencing to characterise haplotypes instead of genome resequencing. Results indicated three haplotypes among 51 local genotypes; there were 26 lines in Haplotype I carrying both the rhg1-a and Rhg4-a resistant loci as in ‘Peking’, 13 lines in Haplotype II containing only the resistant rhg1-a locus but Rhg4-b susceptible loci, and 12 lines in Haplotype III with rhg1-c and Rhg4-b susceptible loci. Interestingly, there was no ‘PI 88788’-type resistance identified in Northeast China, although it accounts for 90% of sources in the USA. Two local breeding lines in Haplotype I displayed resistance to both SCN races. The resistance lines carried higher copy number (>1) of the tandem duplication at the rhg1 locus compared with susceptible lines (⩽1). The combination of the two microsatellite markers, Sat_162 on Chr 8 and 590 on Chr 18, distinguished the three haplotypes and predicted the resistance/susceptibility for SCN race 5. The knowledge of the phenotypes and molecular characteristics of 51 local breeding lines in Northeast China will accelerate the utilisation of sources for broad-based SCN resistance and marker-assisted selection.


2013 ◽  
Vol 1 (1) ◽  
pp. 13-27 ◽  
Author(s):  
T. J. Coulthard ◽  
M. J. Van de Wiel

Abstract. Sediment yields from river basins are typically considered to be controlled by tectonic and climatic drivers. However, climate and tectonics can operate simultaneously and the impact of autogenic processes scrambling or shredding these inputs can make it hard to unpick the role of these drivers from the sedimentary record. Thus an understanding of the relative dominance of climate, tectonics or other processes in the output of sediment from a basin is vital. Here, we use a numerical landscape evolution model (CAESAR) to specifically examine the relative impact of climate change, tectonic uplift (instantaneous and gradual) and basin morphology on sediment yield. Unexpectedly, this shows how the sediment signal from significant rates of uplift (10 m instant or 25 mm a−1) may be lost due to internal storage effects within even a small basin. However, the signal from modest increases in rainfall magnitude (10–20%) can be seen in increases in sediment yield. In addition, in larger basins, tectonic inputs can be significantly diluted by regular delivery from non-uplifted parts of the basin.


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