scholarly journals Discrete, high-latitude foraging areas are important to energy budgets and population dynamics of migratory leatherback turtles

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Bryan P. Wallace ◽  
Michael Zolkewitz ◽  
Michael C. James
2012 ◽  
Vol 9 (9) ◽  
pp. 12087-12136 ◽  
Author(s):  
B. M. Rogers ◽  
J. T. Randerson ◽  
G. B. Bonan

Abstract. Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated the changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would result in surface cooling of 0.23 ± 0.09 °C and 0.43 ± 0.12 °C for winter–spring and February–April time periods, respectively. This could provide a negative feedback to high-latitude terrestrial warming during winter on the order of 4–6% for a doubling, and 14–23% for a quadrupling, of burn area. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.


2013 ◽  
Vol 10 (2) ◽  
pp. 699-718 ◽  
Author(s):  
B. M. Rogers ◽  
J. T. Randerson ◽  
G. B. Bonan

Abstract. Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would cool the surface by 0.23 ± 0.09 °C across boreal North America during winter and spring months (December through May). This could provide a negative feedback to winter warming on the order of 3–5% for a doubling, and 14–23% for a quadrupling, of burn area. Maximum cooling occurs in the areas of greatest burning, and between February and April when albedo changes are largest and solar insolation is moderate. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.


2018 ◽  
Vol 40 (4) ◽  
pp. 446-457 ◽  
Author(s):  
Camilla Svensen ◽  
Maria T Antonsen ◽  
Marit Reigstad

2016 ◽  
Vol 67 (5) ◽  
pp. 594 ◽  
Author(s):  
Christophe Vieira ◽  
Shashank Keshavmurthy ◽  
Se-Jong Ju ◽  
Kiseong Hyeong ◽  
Inah Seo ◽  
...  

Although coral reefs are facing severe challenges from a variety of natural and anthropogenic stresses, there is anecdotal evidence that the high-latitude coral species Alveopora japonica Eguchi, 1968, has increased its population over the past two decades around Jeju Island, off the southern coast of Korea. The present study provides the first ecological data on this species. Alveopora japonica is opportunistically occupying the empty space left vacant following the recent kelp-forest decline. Colony abundance, age- and size-frequency distributions, lifespan, growth rates and biological characteristics such as surface area, weight and volume of two A. japonica populations in Jeju Island were investigated. Alveopora japonica around Jeju Island is characterised by a mean colony size of 30cm2, a slow growth rate (4.8mm year–1), and a short lifespan of 12–13 years, as determined by X-radiographic measurements. Alveopora japonica presented a dense population of 120 colonies m–2 on average. Population-age and -size structures at both sites reflected a healthy status and indicated a local stability, with a stationary size structure allowing population maintenance over time. The present study provided data to develop population-dynamics models to predict the potential outcomes of A. japonica populations to alternative management scenarios in Jeju Island.


2016 ◽  
Vol 17 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Akira MATSUMOTO ◽  
Syohei HASHIMOTO ◽  
Hisayuki ARAKAWA

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