Effects Of Climatic Oscillations Research Articles

The effect of climate oscillations on skipjack tuna (Katsuwonus pelamis) in the Indian Ocean

Skipjack tuna (Katsuwonus pelamis) (SKJ) is one of the most commercially important marine fish species distributed throughout the world's tropical and subtropical oceans. The Indian Ocean is a main fishing ground for SKJ, whose exploitation rate is just below the maximum sustainable yield. Therefore, SKJ stocks may potentially be significantly affected by climate change. In this study, climatic oscillation indices related to the Indian Ocean, including the Indian Ocean Dipole (IOD), the mean water temperature anomaly in the Eastern Indian Ocean (EIO) and Western Indian Ocean (WIO), the Madden-Julian Oscillation Index at 80°E (MJO80) and the Arctic Oscillation Index (AOI), were associated with SKJ catch per unit effort (CPUE). This study aimed to understand the effect of these five climatic oscillations on SKJ, with the goal of optimizing the utilization of skipjack tuna in the Indian Ocean. We combined gradient forest analysis (GFA) and generalized additive models (GAMs) to evaluate the importance of each climatic index with a 0–5 year lag on the impact of SKJ CPUE and to establish an optimal prediction model. The GFA results show that MJO80 is the most important climatic index influencing SKJ CPUE, followed by MJO80_1, AOI_2, IOD_4, WIO_2, etc. The best GAM model includes MJO80, AOI_2, and WIO_2, which could be related to the recruitment and larval survival of SKJ by influencing water temperature. Meanwhile, there is a significant negative correlation between SST and SKJ CPUE in the tropical regions of the western and central Indian Ocean. Our results suggest that climate oscillations have a 0–2 year lag effect on the SKJ fishery in the Indian Ocean, which can be used to predict resource changes in SKJ over the next 2 years.

The Quaternary Range Dynamics of the Dwarf Lizard, Parvilacerta parva (Boulenger, 1887) (Squamata, Lacertidae) in the Anatolian Peninsula

The dwarf lizard, Parvilacerta parva, is a characteristic member of the steppe biome in Irano - Anatolian biological hotspot. While this lizard has been included in local faunistic surveys and its morphological variation was addressed, no targeted study has been performed on the ecology and distribution of the species. Here we investigate the range dynamics of dwarf lizard during recent glacial and interglacial periods. We looked at the effects of climatic oscillations on species distribution at Present, Last Glacial Maximum (LGM), and Last Interglacial (LIG) periods using ecological niche modelling (ENM), based on our own fieldwork and literature data. The model results suggest that the range of dwarf lizards contracted during the LIG and expanded during the LGM, opposite to the pattern observed in many other temperate reptiles. During the LIG, distribution of the dwarf lizards had been restricted to the mountainous steppe habitats in Northeastern Anatolia, but during the LGM it expanded to the west by including the new steppe habitats in Sultan, Emir and Murat mountains and adjacent areas. Climatic factors had a strong influence on shaping the spatiotemporal habitat. The Anatolian Biogeographic Region overlaps with Irano - Anatolian biodiversity hotspot, reflecting remarkable species richness in this area. However, faunal elements of the hotspots are under threat due to not only global climate change, but also anthropogenic pressures, such as habitat loss and overgrazing. Our results suggest that the dwarf lizards have a potential as indicators for tracking the local effects of global climate change as well as human induced degradation of the steppe habitat.

Beyond the trends: The need to understand multiannual dynamics in aquatic ecosystems

Beyond the trends: The need to understand multiannual dynamics in aquatic ecosystems

Phylogeography of a salmonid fish, masu salmon Oncorhynchus masou subspecies‐complex, with disjunct distributions across the temperate northern Pacific

Abstract Climate oscillations during the Pleistocene had profound effects on the evolutionary history of freshwater fishes now distributed across northern temperate regions. The extent of continental glaciation on the western side of the North Pacific, including areas of East Asia, was more limited as compared with regions of North America, Europe and high‐latitude areas of the North Pacific. Therefore, the effects of climate oscillations might have influenced species in dissimilar ways depending on the species' distribution. We used mitochondrial DNA (mtDNA) and microsatellite DNA (msDNA) markers to clarify the evolutionary history of masu salmon Oncorhynchus masou subspecies‐complex (family Salmonidae) distributed in historically non‐glaciated regions in the western North Pacific. No marked regional or subspecies‐specific mtDNA haplotype associations were recognised, except for O. masou subsp., a lacustrine form endemic to Lake Biwa, an ancient lake in central Honshu. The landlocked subspecies O. masou formosanus, with a disjunct distribution on Taiwan Island, exhibited no diagnostic population features differing from the other subspecies, in either mtDNA or msDNA markers. Mismatch distribution and Bayesian skyline plot analyses indicated relatively recent range expansion and rapid population growth for masu salmon during the last glacial period (c. 0.1–0.15 Ma). Contrary to the mtDNA genealogy, Bayesian clustering using msDNA showed two main genetic clusters, mainly northern populations of the subspecies O. m. masou and populations of the subspecies O. m. ishikawae in southern areas of the Japanese Archipelago. Notably, O. m. formosanus on Taiwan Island was included in the O. m. masou group, and O. masou subsp. was included in the O. m. ishikawae group. Our results suggest that the masu salmon subspecies‐complex in historically non‐glaciated regions of the Temperate Northern Pacific is characterised by weak population structuring and shallow genetic differentiation among the subspecies, except for O. masou subsp. owing to its long isolation in Lake Biwa. Incomplete lineage sorting and historical inter‐subspecies hybridisation, possibly due to secondary contact, seem to be plausible explanations for discrepancies in the mitochondrial DNA genealogy and nuclear DNA genetic structure.

Effect of climatic oscillations on flood occurrence on Papaloapan River, México, during the 1550–2000 period

This study presents a chronology of historical and measured flood events in the Papaloapan River basin of Mexico during 450 years. Twenty-eight historical floods were recorded during the period 1550–1948 on this river and one flood event (1969) in the instrumental era (1949–2000), of which 14 were extraordinary floods and only 15 were catastrophic ones. There were several flood-rich decades during 1860–1870, 1880–1890, 1920–1930 and 1940–1950. Wavelet analysis found a significant flooding periodicity of 58 years. The wavelet coherence analysis found that flooding had an in-phase relationship with the Atlantic Multidecadal Oscillation and also with the Pacific Decadal Oscillation. Logistic regression corroborated that there exists a positive relationship between floods events and these two natural climatic oscillations. The logistic regression model predicted correctly 92% of flood events.

Climate variability and the volatility of global maize and soybean prices

Volatility in the price of agricultural commodities is one of the main factors affecting food security. Many studies have analyzed agricultural market instability from different points of view, but the effect of climate oscillations on agricultural price volatility has been little studied. Climate anomalies, and in particular extreme events, can alter agricultural yields and stocks with related effects on prices. This paper presents a Volatility Impulse Response Function (VIRF) from a multivariate GARCH model to investigate the effects of variability in climatic shocks (El Nino/Southern Oscillation - ENSO) on international maize and soybean price volatility from 1960 to 2014. For both commodities, VIRF analysis was conducted splitting the effect of El Nino and La Nina events according to Spring-Summer and Autumn-Winter meteorological seasons. Both events increase expected price volatility of maize, showing the strongest impact during the El Nino phase in Spring-Summer. Soybean price volatility tends to slightly decrease during Autumn-Winter meteorological seasons and to increase during the Spring-Summer period. To minimize the impact of ENSO events on commodity price volatility, various measures can be taken, both political and technical. Financial aspects should also be considered. It is possible that financial agents can use the ENSO index as information for trading activity, creating a new link between this index and volatility in commodity prices.

Effects of climate oscillations on wildland fire potential in the continental United States

AbstractThe effects of climate oscillations on spatial and temporal variations in wildland fire potential in the continental U.S. are examined from 1979 to 2015 using cyclostationary empirical orthogonal functions (CSEOFs). The CSEOF analysis isolates effects associated with the modulated annual cycle and the El Niño–Southern Oscillation (ENSO). The results show that, in early summer, wildland fire potential is reduced in the southwest during El Niño but is increased in the northwest, with opposite trends for La Niña. In late summer, El Niño is associated with increased wildland fire potential in the southwest. Relative to the mean, the largest impacts of ENSO are observed in the northwest and southeast. Climate impacts on fire potential due to ENSO are found to be most closely associated with variations in relative humidity. The connections established here between fire potential and climate oscillations could result in improved wildland fire risk assessment and resource allocation.

Effects of climatic oscillations on the faunas. The Holocene Thermal Maximum and the displacement of armadillos in Argentina: Anatomical features and conservation

The Dasypodidae (commonly known as armadillos) are exclusively from the Americas and have a long evolutionary history on the continents. They were frequently consumed by hunter-gatherers in the past and they are consumed by native people in the modern age along their distributional area. Both paleontological and archaeological records show that they inhabited areas in which they do not inhabit in the present-day. The study conducted on faunal remains at the Alfar site (southeast Buenos Aires Province, Argentina) allowed the determination of two different species (Zaedyus pichiy and Tolypeutes matacus) based on the ornamentation of the osteoderms that compose the animal's carapace. Radiocarbon dating of Unit II (fossil bearing level, 5700yBP) locates the human exploitation during a warm and arid climate period known as the Holocene Thermal Maximum. The armadillos found at Alfar site are absent in the area nowadays. Instead, they are distributed in arid/semiarid environments of the Patagonia and Central regions of Argentina, where the association is characteristic of the Monte ecoregion, 1000km northwest far from Alfar site. The results here presented serve to support the hypothesis of the Dasypodidae as paleoenvironmental proxies and also to confirm the importance of paleozoology studies to apply in conservation biology.

Unravelling the evolutionary history and future prospects of endemic species restricted to former glacial refugia.

The contemporary distribution and genetic composition of biodiversity bear a signature of species' evolutionary histories and the effects of past climatic oscillations. For many European species, the Mediterranean peninsulas of Iberia, Italy and the Balkans acted as glacial refugia and the source of range recolonization, and as a result, they contain disproportionately high levels of diversity. As these areas are particularly threatened by future climate change, it is important to understand how past climatic changes affected their biodiversity. We use an integrated approach, combining markers with different evolutionary rates and combining phylogenetic analysis with approximate Bayesian computation and species distribution modelling across temporal scales. We relate phylogeographic processes to patterns of genetic variation in Myotis escalerai, a bat species endemic to the Iberian Peninsula. We found a distinct population structure at the mitochondrial level with a strong geographic signature, indicating lineage divergence into separate glacial refugia within the Iberian refugium. However, microsatellite markers suggest higher levels of gene flow resulting in more limited structure at recent time frames. The evolutionary history of M.escalerai was shaped by the effects of climatic oscillations and changes in forest cover and composition, while its future is threatened by climatically induced range contractions and the role of ecological barriers due to competition interactions in restricting its distribution. This study warns that Mediterranean peninsulas, which provided refuge for European biodiversity during past glaciation events, may become a trap for limited dispersal and ecologically limited endemic species under future climate change, resulting in loss of entire lineages.

Pollen records of mardel deposits: The effects of climatic oscillations and land management on soil erosion in Gutland, Luxembourg

Typically for the geomorphology of the Luxembourger Gutland is the occurrence of mardels, a local name for small closed depressions. They occur on various substrates and can have a natural or anthropogenic genesis. In general, mardels on the Strassen marls are abandoned quarries, related to historical clay extraction, and mardels on the Luxembourger sandstone are sinkholes, related to joint patterns. Probably, most of the mardels on the Keuper marls are also abandoned quarries but some of them have a natural genesis as subsidence basins related to subsurface dissolutions of gypsum lenses, present in the marl deposits. During the Late Holocene the mardels became filled with colluvial deposits. The pollen records documented in these deposits can be correlated to Subatlantic climatic oscillations and correspond to changes in the rate of soil erosion and land management. In particular, the Little Ice Age stands out as a period with increased denudation and temporary extension of arable land.

Effects of climate oscillations on wind resource variability in the United States

Natural climate variations in the United States wind resource are assessed by using cyclostationary empirical orthogonal functions (CSEOFs) to decompose wind reanalysis data. Compared to approaches that average climate signals or assume stationarity of the wind resource on interannual time scales, the CSEOF analysis isolates variability associated with specific climate oscillations, as well as their modulation from year to year. Contributions to wind speed variability from the modulated annual cycle (MAC) and the El Nino-Southern Oscillation (ENSO) are quantified, and information provided by the CSEOF analysis further allows the spatial variability of these effects to be determined. The impacts of the MAC and ENSO on the wind resource are calculated at existing wind turbine locations in the United States, revealing variations in the wind speed of up to 30% at individual sites. The results presented here have important implications for predictions of wind plant power output and siting.

A multi-decade investigation of primate population dynamics: the effects of climatic oscillations and forest regeneration

A multi-decade investigation of primate population dynamics: the effects of climatic oscillations and forest regeneration

Conceptual Mineral Genesis Models for Calcic Pendants and Petrocalcic Horizons, Nevada

We use the very old, extant, Stage VI Mormon Mesa petrocalcic soil profile in southern Nevada to: (i) present a conceptual model summarizing known spatial and temporal relationships among authigenic calcite (or low-Mg calcite), palygorskite and/or sepiolite, and amorphous silica and (ii) adapt a second model to describe the occurrence of pedogenic barite and the effect of climate oscillations on soil mineralogy at Mormon Mesa. These conceptual models, one compiled from previous research, one built from new data in this study, directly address the importance of dust to soil genesis, especially the control of salt flux and high pH on Ba, Si, and Al mobility in alkaline soil solutions. Authigenesis of calcite and palygorskite/sepiolite creates positive feedbacks with soil solution chemistry that drives further mineralogical development. We explain the occurrence of pedogenic barite at Mormon Mesa based on higher Ba solubility and translocation into the soil profile with increased concentrations of Cl and Mg in soil solutions during interpluvial climates. Development of integrated, mineral development models illustrates individual system components and/or processes that should be targeted for future chemical, biological, geochronologic, or micromorphological study, and provides a basis for comparison of calcic soil genesis from disparate sites around the world.

Host-parasite interactions and global climate oscillations

It is suspected that host-parasite interactions are influenced by climatic oscillations such as the North Atlantic Oscillation (NAO). However, the effects of climatic oscillations on host-parasite interactions have never been investigated. A long-term (1982-1999) dataset of the host snail Lymnaea stagnalis and trematode metacercariae infection has been collected for Lake Chany in Western Siberia. Using this dataset, we estimated the impact of the NAO on the population dynamics of hosts and parasites as well as their interactions. The results of general linear models showed that the abundance of dominant parasite species and the total parasite abundance significantly increased with NAO, with the exception of Moliniella anceps. Other climatic and biological factors were relatively weak to explain the abundance. There was no significant relationship between NAO and the population density of host snails. The prevalence of infection was related to the total abundance of parasites, but not to the NAO. Thus, the responses to the NAO differed between the host and parasites, indicating mismatching in host-parasite interactions. Therefore, climatic oscillations, such as the NAO, influence common parasitism.

The influence of climatic oscillations during the Quaternary Era on the genetic structure of Asian black bears in Japan

The Asian black bear (Ursus thibetanus) inhabits two of the main islands, Honshu and Shikoku, in Japan. To determine how climatic oscillations during the Quaternary Era affected the genetic structure of the black bear populations in Japan, we examined their phylogeographic relationships and compared their genetic structure. We analysed an approximately 700-bp sequence in the D-loop region of mitochondrial DNA collected from 589 bears in this study with 108 bears from a previous study. We observed a total of 57 haplotypes and categorized them into three clusters (Eastern, Western and Southern) based on the spatial distribution of the haplotypes. All but 2 of the 41 haplotypes in the Eastern cluster were distributed locally. Genetic diversity was generally low in northern Japan and high in central Japan. Demographic tests rejected the expansion model in northern populations. Haplotypes of the Western and Southern clusters were unique to local populations. We conclude that the extant genetic structure of the Asian black bear populations arose as follows: first, populations became small and genetic drift decreased genetic diversity in the northern area during the last glacial period, whereas large continuous populations existed in the southern part of central Japan. These patterns were essentially maintained until the present time. In western and southern Japan, the effects of climatic oscillations were smaller, and thus, local structure was maintained.

Population dynamics of rice rats (a Hantavirus reservoir) in southern Chile: feedback structure and non‐linear effects of climatic oscillations

We studied a fluctuating population of the long‐tail rice rat (Oligoryzomys longicaudatus), the main Hantavirus vector in southern Chile, and spanning 19 years of monitoring. We determined that a first‐order feedback structure and non‐linear effects of Antarctic Oscillation Index (AAOI) and Southern Oscillation Index (SOI) explain 96% of the variation in annual per capita population growth rates. One important result of this study is that first‐order feedback structure captures the essential features of population dynamics of long‐tailed rice rats. This regulatory structure suggests that rice rats are limited by food, space or predators and regulated by intra‐specific competition. The first‐order dynamics observed in long‐tailed rice rats strongly suggests that Hantavirus have no harmful effects on survival or reproductive processes. Besides the non‐linear climatic signature in population dynamics, the periodic event of bamboo‐flowering and mast seeding strongly influence rice rats population growth rates. Because of this, bamboo flowering may be used as a signal for forecasting long‐tail rice rats outbreaks and for implementing information and health policies to avoid human‐rodent contacts in specific areas. The observed effects of the two large‐scale climatic indexes that influence climatic variability along southern Pacific Ocean, the AAOI and the SOI, emphasizes the role of considering non‐linear feedback structures and climatic forces for understanding small rodent population dynamics. Because long‐tailed rice rats represent the major Hantavirus reservoir in southern Chile and Argentina, we need to gain an in‐depth understanding of the structure and functioning of these small rodent populations in face of the potential consequences of global change and climatic fluctuations.