Range-wide Persistence of the Endangered Arroyo Toad (Anaxyrus californicus) for 20+ Years Following a General Warming Trend and Prolonged Drought

Climate change and prolonged drought have negatively impacted amphibians in southern California, U.S.A. Due to the severe drought from 2012–2016, agencies and researchers had growing concern for the persistence of the arroyo toad (Anaxyrus californicus), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least 20 years. In 2017–2020 we conducted collaborative surveys for arroyo toads at historical locations. We surveyed 87 of the 115 total sites having historical records and confirmed that the arroyo toad is currently extant in 60 of 87 sites and 19 of 25 historically occupied watersheds. Only detection/non-detection and not population size was recorded, therefore potential declines at the population level could not be assessed. In other amphibian species, body condition has been documented to decrease with a decrease in water availability. To further investigate the drought’s impact on this species, we calculated an average body condition index annually for arroyo toads using allometric measurements recorded from 1996–present. This index was plotted against precipitation records over time. Our data show that body condition did not significantly change during drought years, but hydro-regulation may be masking an effect. Our study suggests that this species shows some resiliency to climate change and drought, and that mitigating invasive species, hydro-modification, and other anthropogenic drivers may currently be the most beneficial strategy for toad conservation. Arroyo toad conservation actions may also provide simultaneous benefits to several other native species that share the same habitat.

Download Full-text

Continued Hydrothermal and Radiative Pressure on Changed Cropland in China

Sustainability ◽

10.3390/su11143762 ◽

2019 ◽

Vol 11 (14) ◽

pp. 3762 ◽

Cited By ~ 1

Author(s):

Yiming Fu ◽

Yaoping Cui ◽

Yaochen Qin ◽

Nan Li ◽

Liangyu Chen ◽

...

Keyword(s):

Climate Change ◽

Solar Radiation ◽

Break Line ◽

Warming Trend ◽

Severe Drought ◽

Agricultural Water Use ◽

Northern Regions ◽

Increasing Temperature ◽

Over Time

Both cropland and climate change over time, but the potential effects of climate change on cropland is currently not well understood. Here, we combined temporally and spatially explicit dynamics of cropland with air temperature, precipitation, and solar radiation datasets. China’s cropland showed a clear northward-shifting trend from 1990 to 2015. The cropland decreased south of the break line at 38° N, whereas it increased from the break line to northern regions. Correspondingly, the temperature showed a significant warming trend in the early part of the study period, which slowed down in later years. During the whole study period, both precipitation and solar radiation decreased over time, showed no significant linear characteristics, and the annual fluctuations were very large. The cropland areas in China showed a displacement characteristic with the increasing temperature, precipitation, and radiation. Overall, the cropland was shifting towards the high-temperature, low-precipitation, and low-radiation areas. The cropland dynamics indicate that they are likely to face severe drought and radiation pressure. Our findings imply that more resources such as irrigation may be needed for cropland, which will undoubtedly aggravate the agricultural water use in most northern regions, and the potential impacts on food security will further emerge in the future.

Download Full-text

Synergistic impacts of global warming and thermohaline circulation collapse on amphibians

Communications Biology ◽

10.1038/s42003-021-01665-6 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Julián A. Velasco ◽

Francisco Estrada ◽

Oscar Calderón-Bustamante ◽

Didier Swingedouw ◽

Carolina Ureta ◽

...

Keyword(s):

Climate Change ◽

Global Warming ◽

Thermohaline Circulation ◽

Climate Model ◽

Global Climate ◽

Extinction Risk ◽

Meridional Overturning Circulation ◽

Mitigation Strategies ◽

Amphibian Species ◽

Climate Conditions

AbstractImpacts on ecosystems and biodiversity are a prominent area of research in climate change. However, little is known about the effects of abrupt climate change and climate catastrophes on them. The probability of occurrence of such events is largely unknown but the associated risks could be large enough to influence global climate policy. Amphibians are indicators of ecosystems’ health and particularly sensitive to novel climate conditions. Using state-of-the-art climate model simulations, we present a global assessment of the effects of unabated global warming and a collapse of the Atlantic meridional overturning circulation (AMOC) on the distribution of 2509 amphibian species across six biogeographical realms and extinction risk categories. Global warming impacts are severe and strongly enhanced by additional and substantial AMOC weakening, showing tipping point behavior for many amphibian species. Further declines in climatically suitable areas are projected across multiple clades, and biogeographical regions. Species loss in regional assemblages is extensive across regions, with Neotropical, Nearctic and Palearctic regions being most affected. Results underline the need to expand existing knowledge about the consequences of climate catastrophes on human and natural systems to properly assess the risks of unabated warming and the benefits of active mitigation strategies.

Download Full-text

Drought and Saline Stress Tolerance Induced in Somatic Hybrids of Solanum chacoense and Potato Cultivars by Using Mismatch Repair Deficiency

Agriculture ◽

10.3390/agriculture11080696 ◽

2021 ◽

Vol 11 (8) ◽

pp. 696

Author(s):

Imola Molnár ◽

Lavinia Cozma ◽

Tünde-Éva Dénes ◽

Imre Vass ◽

István-Zoltán Vass ◽

...

Keyword(s):

Climate Change ◽

Mismatch Repair ◽

Crop Production ◽

Somatic Hybrids ◽

Potato Cultivars ◽

Solanum Chacoense ◽

Saline Stress ◽

Severe Drought ◽

Mismatch Repair Deficiency ◽

Repair Deficiency

Global climate change, especially when involving drought and salinity, poses a major challenge to sustainable crop production, causing severe yield losses. The environmental conditions are expected to further aggravate crop production in the future as a result of continuous greenhouse gas emissions, causing further temperature rise and leading to increased evapotranspiration, severe drought, soil salinity, as well as insect and disease threats. These suboptimal growth conditions have negative impact on plant growth, survival, and crop yield. Potato is well known as a crop extremely susceptible to drought, which is primarily attributed to its shallow root system. With potato being the fourth major food crop, increasing potato productivity is thus important for food security and for feeding global population. To maintain a sustainable potato production, it is necessary to develop stress tolerant potato cultivars that cope with the already ongoing climate change. The aim of our study is to analyze the response of potato somatic hybrids to drought and salt stress under in vitro conditions; the somatic hybrids studied are the wild relative Solanum chacoense (+) Solanum tuberosum, with or without mismatch repair deficiency (MMR). Upon this selection of drought and salt tolerant genotypes, somatic hybrids and their parents were phenotyped on a semi-automated platform, and lines tolerant to medium water scarcity (20% compared to 60% soil water capacity) were identified. Although none of the parental species were tolerant to drought, some of the MMR-deficient somatic hybrids showed tolerance to drought and salt as a new trait.

Download Full-text

Towards Vine Water Status Monitoring on a Large Scale Using Sentinel-2 Images

Remote Sensing ◽

10.3390/rs13091837 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1837

Author(s):

Eve Laroche-Pinel ◽

Sylvie Duthoit ◽

Mohanad Albughdadi ◽

Anne D. Costard ◽

Jacques Rousseau ◽

...

Keyword(s):

Climate Change ◽

Water Potential ◽

Large Scale ◽

Water Status ◽

Vegetation Indices ◽

Machine Learning Algorithms ◽

Severe Drought ◽

Stem Water Potential ◽

Stem Water ◽

Sentinel 2

Wine growing needs to adapt to confront climate change. In fact, the lack of water becomes more and more important in many regions. Whereas vineyards have been located in dry areas for decades, so they need special resilient varieties and/or a sufficient water supply at key development stages in case of severe drought. With climate change and the decrease of water availability, some vineyard regions face difficulties because of unsuitable variety, wrong vine management or due to the limited water access. Decision support tools are therefore required to optimize water use or to adapt agronomic practices. This study aimed at monitoring vine water status at a large scale with Sentinel-2 images. The goal was to provide a solution that would give spatialized and temporal information throughout the season on the water status of the vines. For this purpose, thirty six plots were monitored in total over three years (2018, 2019 and 2020). Vine water status was measured with stem water potential in field measurements from pea size to ripening stage. Simultaneously Sentinel-2 images were downloaded and processed to extract band reflectance values and compute vegetation indices. In our study, we tested five supervised regression machine learning algorithms to find possible relationships between stem water potential and data acquired from Sentinel-2 images (bands reflectance values and vegetation indices). Regression model using Red, NIR, Red-Edge and SWIR bands gave promising result to predict stem water potential (R2=0.40, RMSE=0.26).

Download Full-text

Are roads and traffic sources of physiological stress for the Florida scrub-jay?

Wildlife Research ◽

10.1071/wr11029 ◽

2012 ◽

Vol 39 (4) ◽

pp. 301 ◽

Cited By ~ 8

Author(s):

Gina M. Morgan ◽

Travis E. Wilcoxen ◽

Michelle A. Rensel ◽

Stephan J. Schoech

Keyword(s):

Body Mass ◽

Body Condition ◽

Physiological Stress ◽

Condition Index ◽

Physiological Effects ◽

Negative Effects ◽

Florida Scrub ◽

The Road ◽

Threatened And Endangered Species ◽

Chronic Stressor

Context Anthropogenic disturbances induce physiological and behavioural responses in numerous species. The negative effects of human disturbance are of special concern to threatened and endangered species. Aims The present study aims to compare physiological stress measures and reproductive success of Florida scrub-jays (Aphelocoma coerulescens) living near roads with jays that live away from roads. Specifically, it aims to test whether roads are stressful. Methods We assessed physiological measures that can serve as indicators of ‘stress’ to determine whether a highway that bisects our study site had physiological effects on adult male Florida scrub-jays. We captured male breeders from three territory types, including scrub habitat that (1) bordered a highway with a grassy shoulder that created an ‘edge’ habitat (roadside), (2) bordered human-maintained habitat (a plowed firebreak of sand with adjacent pasture) that served as a control for the edge-effect of the road (pasture) and (3) contained only natural scrub habitat (interior). We measured baseline concentrations of the stress hormone corticosterone (CORT), body mass, and a suite of longitudinal body measures to generate a body condition index in males from each territory type over three breeding seasons. Key results Roadside jays had greater body mass than did interior and pasture jays, although there were no differences in overall baseline CORT concentrations or body condition among territory classes. There was no difference in clutch initiation date or size and nestling and independent-young survival. Conclusions Our results suggest that the road through our study site has physiological effects on Florida scrub-jays; however, there is mixed evidence as to whether it acts as a chronic stressor. Implications Our findings provide evidence that roads and road-associated disturbance has neutral or potentially beneficial physiological effects of roads on Florida scrub-jays. Knowledge of these effects of roads and disturbance on jays will hopefully provide additional opportunities to improve conservation of this species.

Download Full-text

Do researchers impact their study populations? Assessing the effect of field procedures in a long term population monitoring of sea kraits

Amphibia-Reptilia ◽

10.1163/15685381-00002839 ◽

2012 ◽

Vol 33 (3-4) ◽

pp. 365-372 ◽

Cited By ~ 11

Author(s):

Thomas Fauvel ◽

François Brischoux ◽

Marine Jeanne Briand ◽

Xavier Bonnet

Keyword(s):

Body Condition ◽

New Caledonia ◽

Stress Hormones ◽

Population Level ◽

Population Monitoring ◽

Long Term Effects ◽

Negative Effects ◽

Short Term ◽

Head Morphology

Long term population monitoring is essential to ecological studies; however, field procedures may disturb individuals. Assessing this topic is important in worldwide declining taxa such as reptiles. Previous studies focussed on animal welfare issues and examined short-term effects (e.g. increase of stress hormones due to handling). Long-term effects with possible consequences at the population level remain poorly investigated. In the present study, we evaluated the effects of widely used field procedures (e.g. handling, marking, forced regurgitation) both on short-term (hormonal stress response) and on long-term (changes in body condition, survival) scales in two intensively monitored populations of sea kraits (Laticauda spp.) in New Caledonia. Focusing on the most intensively monitored sites, from 2002 to 2012, we gathered approximately 11 200 captures/recaptures on 4500 individuals. Each snake was individually marked (scale clipping + branding) and subjected to various measurements (e.g. body size, head morphology, palpation). In addition, a subsample of more than 500 snakes was forced to regurgitate their prey for dietary analyses. Handling caused a significant stress hormonal response, however we found no detrimental long-term effect on body condition. Forced regurgitation did not cause any significant effect on both body condition one year later and survival. These results suggest that the strong short-term stress provoked by field procedures did not translate into negative effects on the population. Although similar analyses are required to test the validity of our conclusions in other species, our results suggest distinguishing welfare and population issues to evaluate the potential impact of population surveys.

Download Full-text

Resource partitioning between kit foxes (Vulpes macrotis) and coyotes (Canis latrans): a comparison of historical and contemporary dietary overlap

Canadian Journal of Zoology ◽

10.1139/cjz-2017-0246 ◽

2018 ◽

Vol 96 (5) ◽

pp. 497-504 ◽

Cited By ~ 12

Author(s):

P.A. Byerly ◽

R.C. Lonsinger ◽

E.M. Gese ◽

A.J. Kozlowski ◽

L.P. Waits

Keyword(s):

Great Basin ◽

Native Species ◽

Dietary Diversity ◽

Canis Latrans ◽

Population Level ◽

Relative Importance ◽

Dietary Overlap ◽

Kit Fox ◽

Prey Diversity ◽

Vulpes Macrotis

Range expansions by generalists can alter communities and introduce competitive pressures on native species. In the Great Basin Desert, USA, coyotes (Canis latrans Say, 1823) have colonized and are now sympatric with native kit foxes (Vulpes macrotis Merriam, 1888). Since both species have similar diets, dietary partitioning may facilitate coexistence. We analyzed coyote and kit fox diets, then compared our results to an earlier study. Because populations are dynamic, we expected that decreases in prey or increases in predator abundance could alter dietary patterns. We found no significant changes in population-level prey diversity for kit foxes or coyotes, but found high levels of dietary overlap between species. We did detect a significant decrease in the relative importance of leporids (family Leporidae) in the diets of both canids, but they remained important for coyotes. The relative importance of small mammals was greater for kit foxes than coyotes, but their importance had not changed significantly over time. We detected significant declines in prey diversity per sample (scat-level dietary diversity) for both canids, suggesting that during a foraging event, individuals may encounter less diverse prey now than historically. These findings suggested that kit foxes and coyotes were not limited by prey, despite high dietary overlap.

Download Full-text

Changes in the Amplitude of the Temperature Annual Cycle in China and Their Implication for Climate Change Research

Journal of Climate ◽

10.1175/jcli-d-11-00006.1 ◽

2011 ◽

Vol 24 (20) ◽

pp. 5292-5302 ◽

Cited By ~ 42

Author(s):

Cheng Qian ◽

Congbin Fu ◽

Zhaohua Wu

Keyword(s):

Climate Change ◽

Annual Cycle ◽

Linear Trend ◽

Surface Air Temperature ◽

Mean Amplitude ◽

Warming Trend ◽

Ensemble Empirical Mode Decomposition ◽

Surface Solar Radiation ◽

Climate Change Research ◽

Annual Cycles

Abstract Climate change is not only reflected in the changes in annual means of climate variables but also in the changes in their annual cycles (seasonality), especially in the regions outside the tropics. In this study, the ensemble empirical mode decomposition (EEMD) method is applied to investigate the nonlinear trend in the amplitude of the annual cycle (which contributes 96% of the total variance) of China’s daily mean surface air temperature for the period 1961–2007. The results show that the variation and change in the amplitude are significant, with a peak-to-peak annual amplitude variation of 13% (1.8°C) of its mean amplitude and a significant linear decrease in amplitude by 4.6% (0.63°C) for this period. Also identified is a multidecadal change in amplitude from significant decreasing (−1.7% decade−1 or −0.23°C decade−1) to significant increasing (2.2% decade−1 or 0.29°C decade−1) occurring around 1993 that overlaps the systematic linear trend. This multidecadal change can be mainly attributed to the change in surface solar radiation, from dimming to brightening, rather than to a warming trend or an enhanced greenhouse effect. The study further proposes that the combined effect of the global dimming–brightening transition and a gradual increase in greenhouse warming has led to a perceived warming trend that is much larger in winter than in summer and to a perceived accelerated warming in the annual mean since the early 1990s in China. It also notes that the deseasonalization method (considering either the conventional repetitive climatological annual cycle or the time-varying annual cycle) can also affect trend estimation.

Download Full-text

Rodent helminths in fragmented Atlantic Forest areas in the western region of the state of Paraná

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612021058 ◽

2021 ◽

Vol 30 (3) ◽

Author(s):

Danise Benatti ◽

Luis Felipe Andrietti ◽

José Flávio Cândido Júnior ◽

Alexandre Vogliotti ◽

Marcela Figueirêdo Duarte Moraes ◽

...

Keyword(s):

Atlantic Forest ◽

Body Condition ◽

Condition Index ◽

Ecological Indicators ◽

The Body ◽

Western Region ◽

Body Condition Index ◽

Intensity Of Infection ◽

New Host ◽

The Western Region

Abstract Rodents are small mammals that can be parasitized by various helminths. This study aimed to identify and describe the ecological indicators of infection in rodents captured in fragments of the Atlantic Forest in the western region of Paraná State, Brazil. Sixty-eight specimens of five rodent species were collected, necropsied, and inspected in search of helminths. The parasites were stored in 70% ethanol, morphologically identified, and counted for calculation of infection indicators. Fourteen species of helminths and one species of Crustacea were recorded: ten in Akodon montensis, four in Mus musculus, two in Thaptomys nigrita, two in Oligoryzomys nigripes, and one in Euryoryzomys russatus. The registered species of parasites were: Rodentolepis akodontis, Angiostrongylus sp., Protospirura numidica criceticola, Trichuris navonae, Syphacia alata, Syphacia criceti, Syphacia evaginata, Trichofreitasia lenti, Stilestrongylus aculeata, Stilestrongylus eta, Stilestrongylus gracielae, Stilestrongylus franciscanus, Stilestrongylus moreli, Stilestrongylus sp., and Pentastomida gen. sp. A positive correlation between the intensity of infection of T. navonae and T. lenti was observed with the body condition index of the host A. montensis. For all species, this study represents a new register of locality, and for eight of them a new host.

Download Full-text

Korelasi Antara Resistensi Survival Rate dan Body Condition Index (BCI) dengan Stress Suhu Pada Kerang Hijau di Muara Kamal, Jakarta

Jurnal Ilmiah Satya Minabahari ◽

10.53676/jism.v2i1.22 ◽

2016 ◽

Vol 2 (1) ◽

pp. 67-76

Author(s):

Yasser Ahmed ◽

Armin Fabritzek ◽

Neviaty P. Zamani ◽

Karen Von Juterzenka ◽

Mark Lenz

Keyword(s):

Survival Rate ◽

Body Condition ◽

Condition Index ◽

Body Condition Index

Pergerakan organisme dipengaruhi oleh penyebaran alami dan aktivitas manusia.Beberapa spesies yang terbawa, memiliki sebaran yang melebihi distribusi batas normal oleh pengaruh tertentu (vector).Penelitian ini melakukan pengujian pada skala laboratorium untuk melihat survival rate yang terkait dengan body condition index selama diberikan stress suhu yang terkait perubahan iklim dan ini juga dapat dijadikan sebagai simulasi transportasi kapal, sehingga dapat diketahui pergerakan organisme.Distribusi organisme tersebut mempengaruhi kemampuan bertahan hidupselama transportasi.Oleh karena itu, perlu dilakukan penelitian dengan mengekspose grup pra-stress dan grup non stress sebelum masuk ke fase stress dan membandingkan survival rate dan body condition index (BCI) pada organisme tersebut. Organisme yang dipilih adalah Kerang Hijau (P. viridis) dengan menggunakan stress suhu.Pengukuran respon variabel dari organisme tersebut yaitu survival rate dan body condition index (BCI).Penelitian ini menunjukkan bahwa survival rate dan body condition index memiliki korelasi linier.

Download Full-text