Potential impact of global warming on deciduous oak dieback caused by ambrosia fungus Raffaelea sp. carried by ambrosia beetle Platypus quercivorus (Coleoptera: Platypodidae) in Japan

2002 ◽  
Vol 92 (2) ◽  
pp. 119-126 ◽  
Author(s):  
N. Kamata ◽  
K. Esaki ◽  
K. Kato ◽  
Y. Igeta ◽  
K. Wada

AbstractDeciduous oak dieback in Japan has been known since the 1930s, but in the last ten years epidemics have intensified and spread to the island’s western coastal areas. The symbiotic ambrosia fungus Raffaelea sp. is the causal agent of oak dieback, and is vectored by Platypus quercivorus (Murayama). This is the first example of an ambrosia beetle fungus that kills vigorous trees. Mortality of Quercus crispula was approximately 40% but much lower for associated species of Fagaceae, even though each species had a similar number of beetle attacks. It is likely that other oaks resistant to the fungus evolved under a stable relationship between the tree, fungus and beetle during a long evolutionary process. Quercus crispula was probably not part of this coevolution. This hypothesis was supported by the fact that P. quercivorus showed the least preference for Q. crispulayet exhibited highest reproductive success in this species. Therefore, P. quercivorus could spread more rapidly in stands with a high composition of Q. crispula. The present oak dieback epidemic in Japan probably resulted from the warmer climate that occurred from the late 1980s which made possible the fateful encounter of P. quercivorus with Q. cripsula by allowing the beetle to extend its distribution to more northerly latitudes and higher altitudes. Future global warming will possibly accelerate the overlapping of the distributions of P. quercivorus and Q. crispula with the result that oak dieback in Q. crispula will become more prevalent in Japan.

2014 ◽  
Vol 44 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Michimasa Yamasaki ◽  
Yasuto Ito ◽  
Makoto Ando

Bark and ambrosia beetles sometimes kill trees by attacking them en masse; however, their attack is not necessarily successful. Less than half of the fagaceous trees attacked by the ambrosia beetle Platypus quercivorus (Murayama) die, and the factors affecting this mortality are still unknown. To examine this issue, the survival of all stems of fagaceous trees attacked by the ambrosia beetle was investigated in a secondary forest from 2008 to 2010. In an area of 93 ha, 2130 stems (1278 genets) of fagaceous trees were attacked by P. quercivorus during the study period, and 813 of these stems died. A generalized additive mixed model was constructed to predict the probability of mortality of the attacked stems. A best-fit model showed that the probability of mortality was higher in Quercus crispula Blume than in Castanea crenata Sieb. & Zucc. A positive correlation was determined between the density of the attacked trees and the probability of mortality, suggesting that mass attack of P. quercivorus occurs not only on individual trees, but also on groups of trees. Assuming that trees attacked earlier in the season have a higher probability of mortality, the observed negative effects of altitude suggest that P. quercivorus initially seeks hosts at lower elevations.


2019 ◽  
Author(s):  
Jennifer D. Wagner ◽  
Daniel J. Peppe ◽  
Jennifer M.K. O'Keefe ◽  
Christopher Dennison

During the early Paleogene the Earth experienced long-term global warming punctuated by several short-term ‘hyperthermal’ events, the most pronounced of which is the Paleocene-Eocene Thermal Maximum (PETM). During this time, tropical climates expanded into extra-tropical areas potentially forming a wide band of ‘paratropical’ forests that are hypothesized to have expanded into the mid-latitude Northern Great Plains (NGP). Relatively little is known about these ‘paratropical’ floras, which would have extended across the Gulf Coastal Plain (GCP). This study assesses the preserved floras from the GCP in Central Texas before and after the PETM to define plant ecosystem changes associated with the hyperthermal event in this region. These floras suggest a high turnover rate, change in plant community composition, and uniform plant communities across the GCP at the Paleocene-Eocene boundary. Paleoecology and paleoclimate estimates from Central Texas PETM floras suggest a warm and wet environment, indicative of tropical seasonal forest to tropical rainforest biomes. Fossil evidence from the GCP combined with data from the NGP and modern tropics suggest that warming during the PETM helped create a ‘paratropical belt’ that extended into the mid-latitudes. Evaluating the response of plant communities to rapid global warming is important for understanding and preparing for current and future global warming and climate change.


2013 ◽  
Vol 31 (9) ◽  
pp. 1591-1596 ◽  
Author(s):  
G. R. Sonnemann ◽  
M. Grygalashvyly

Abstract. The estimated global CO2 emission rates and the measured atmospheric CO2 concentrations show that only a certain share of the emitted CO2 accumulates in the atmosphere. For given atmospheric emissions of CO2, the effective lifetime determines its accumulation in the atmosphere and, consequently, its impact on the future global warming. We found that on average the inferred effective lifetime of CO2 decreases as its atmospheric concentration increases, reducing the rate of its accumulation in the atmosphere. We derived a power function that fits the varying lifetimes. Based on this fitting function, we calculated the increase of CO2 for different scenarios of future global emission rates.


2021 ◽  
Author(s):  
Amal John ◽  
Hervé Douville ◽  
Pascal Yiou

<p>Daily precipitation extremes are projected to intensify with global warming. Here the focus is on how extreme precipitation scales with the changing global mean surface air temperature (GSAT) and how much their inherent seasonality will change, using historical and SSP5-8.5 scenario simulations from 18 CMIP6 models for different sub-domains over Europe. With strong future global warming, the annual maximum precipitation (RX1DAY) is found to occur later in the year, although this shift is model-dependent and hardly significant in the multi-model distribution. Using generalized extreme value theory also provides evidence for the intensification of wet extremes in the future. In addition, we use monthly model outputs to decompose changes in RX1DAY occurring at the peak of the extreme season into several contributions, which gives insights into the underlying physical mechanisms that control the response of precipitation extremes and their inter-model spread.</p>


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