DIWPA: DIVERSITAS in the Western Pacific and Asia

DIWPA News Letter
Office: Center for Ecological Research, Kyoto University, Otsu, Japan

Message from the Chairperson
Shin-ichi Nakano

Unfor t unately, we st ill have t heserious spread of COVID-19 all overthe world. The COVID-19 problems have had anegative impact on CER as well as others, andwe made “lock-down” from 27 April to 15 May
at the closure request by Shiga Prefecture. Many
colleagues were under the stress of “Stay-at-home”
mission, inconvenient life, loneliness and negative
news during the lock-down. CER has been released
from lock-down now, and we have been gradually
opening and re-starting our research activities.
Some of you might think that the COV ID-19
problems would be tackled and solved by medical,
viral and pharmacy researchers. However, I believethat ecologists and biodiversity researchers cancontribute something to settle the problems. It canbe said that COVID-19 virus would have diversity
because it would not be a single virus, consisting ofsome or many genotypes. At the present, medical,
viral and pharmacy researchers all over the world

Message from the Secretary General

Atsushi Ishida

Many researchers and policy makers
are conf ronted w it h a dif f icult
situation to continue their usual study, lectureand meetings because of COVID-19 pandemic
now. Unfortunately, we have to postpone or cease
the International Field Biology Course (IFBC) inthis year. Although the first weave of COVID-19
has been closed in Japan, we cannot predictcoming of the second wave. I am aware that you
still suffer from the first wave in many countries
in the world.
Separately from COVID-19, I feel that thefrequency of new infections, such as SARS andMARS, is increasing recently. It comes dueto the globalism, and it also may be related
to the global warming and the progressing
nature destruction in the world. However, thisJune2020

No.

43

have been studying and developing vaccine and/orspecific medicine for COVID-19. Because there is apossibility that each country/region has different
genotype (s) of COVID-19, various types of thevaccine and/or specific medicine for COVID-19
must be studied and developed. Ecologists andbiodiversity researchers would be able to provide
necessary tools and information about analysesof genotype variation. In addition, the spread
and/or biogeography of microorganisms are
one of important research fields for ecolog yand biodiversity. Ecological approach would beneeded to know the process of transportation andacclimation by newly invading biological species,
and biodiversity research would be necessary toknow their variation of survival. Not only medical,viral and pharmacy researchers but ecologists
and biodiversit y researches would also haveimportant roles for solution of COVID-19 problems.
Thus, we can scientifically contribute to preventthe virus from the spread. I hope all the peoplein our planet would be freed from the threat by
COVID-19 soon.

pandemic has clarified the importance of sharing
exact information speedy all over the world.
Furthermore, we learned the importance ofworking altogether to overcome various troubles
by holding hands in the world. This is common
issue in not only the pandemic but also global
warming and the decline of biodiversity. We will
use online systems for lectures and meetings tokeep social distance from now. And we will know
the merit and demerit of both online and face-toface systems. Furthermore, we have to remake
the social structure with citizen, governments
and researchers altogether to overcome variousissues. I am certain that platform to exchange
information will be more important. DIWPA
must contribute to the significance.
We will upload more information about
IFBC in this year on our HP depending on the
COVID-19 pandemic. I appreciate your support tokeep and enhance DIWPA activities.
DIWPA News Letter No.43

1

ReportWhat is necessary to suppress
global warming up to 1.5℃ ?
Shin Matsuyama

Center for Ecological Research, Kyoto University (Japan)

Ongoing climate change has caused
severe drought, being reported all overthe world. The Work Meteorological2018 ) summarizes the future risks onnatural and human systems at 1.5℃ versus

Organization ( WMO) confirms 2019 as

2℃ of global warming, and concludes

above pre-industrial levels (WMO 2020). Air

needed for maintaining sustainable natural

second hottest year on record. The global

mean temperature for 2019 was 1.1℃

temperature is one indicator of the ongoingclimate change. Heat waves with prolonged
drought induce not only forest fires but alsoflood. In Australia, it was driest and hottest

on record in 2019; the averaged maximum
temperature across the country reached

41.9℃ on December 18, 2019. The greatest
forest fire on record continued during 240

days from July of 2018 to March of 2019 inAustralia. The prolonged drought induced
large tree death and resulting forest fire
killed more than 1 billion endemic animals.

Enormous cost and time will be needed forthe recovering of ecosystems, and it may bedifficult to be back to the entirely originalnature. In California, the longest droughtthat the limiting warming to 1.5℃ above

temperature in pre-industrial levels isand human systems.

The report of IPCC comprehensively

describes the high risks of global warming in

extreme weather, sea-level rise, ecosystems,health, food, and water resources with afocus on how risk levels change from 1.5℃ to

2℃ of global warming (IPCC 2018). According

to the report, the sea-level rise is estimatedto be suppressed within about 10 cm in 2100

years at 1.5℃ compared to 2℃. On land, theimpacts on biodiversity and ecosystems,
including the extinction of species, areexpected to be lower at global warming of1.5℃ compared to 2℃ (IPCC SR1.5 SPM

B2). In terrestrial ecosystems, a warmingof 1.5℃ will result in 6% of insects, 8% ofoccurred from December of 2011 to Marchplants, and 4% of vertebrates losing more

food insecurity. The drought of the future

will result in 18% of insects, 16% of plants,of 2019, lasting 376 weeks. The reductionsin the crop and livestock production led tois likely to be more frequent, severe, andlonger-lasting than they have been in recentdecades (Ault 2020). The Intergovernmental
2Report: Global Warming of 1.5℃ (IPCC

Panel on Climate Change (IPCC ) Special
DIWPA News Letter No.43

than half their climatically determining
geographic range. On the other hand, 2.0℃
and 8% of vertebrates losing more than half

their climatically determining geographicrange ( Warren et al. 2018 ) . In addition,

the increase in CO2 associated with global

Reportwarming leads to ocean acidification,energy system is estimated to be about $ 2.4

ecosystems. This is more pronounced at aenergy will increase, but the investment

affecting species growth, development,
calcification, and sur vival in marine
2℃ rise than at a 1.5℃ rise. In the case ofcoral reefs, it is estimated that a rise of 1.5℃
will reduce 70% to 90%, and that of 2℃
will lose 99% or more. An increase of 1.5℃
will thus have an impact on the ecosystemand humankind, but it will be suppressedmore than an increase of 2℃ (IPCC SR1.5trillion annually, which is about 2.5% of theworld's GDP. The investment in renewablein fossil fuels will decrease. As the result,the investment for transform of energy

system will only increase by about 20%.
With the transform of energy system, weneed the rapid system transformation insociety, such as land use, infrastructureand industry (IPCC SR1.5 SPM C2.6). It isSPM B4) . The IPCC report has enhanced

also necessary to remove CO 2 from theglobal warming to a rise of 1.5℃ (IPCC

products (Carbon Dioxide Removal: CDR).

that it is necessary to reduce global net CO2emissions to zero by 2050 for suppressing

atmosphere, and to permanently store it

into underground, land or sea reservoir andSR1.5 SPM C1).

CDR includes bioenergy, which can capture

lifestyles, etc. regarding mitigation routes

reforestation. The IPCC report estimates

The IPCC report derives a wide range of

economic growth, technological advances,
to keep the air temperature rise to 1.5℃

before the Industrial Revolution ( IPCC

and store carbon that CO2 is not released

into the atmosphere, and afforestation andthat in 2050, the CDR will be used for about

100 to 1,000 Gt CO2 over the 21st century

SR1.5 SPM C2) . It suggests that carbon(IPCC SR1.5 SPM C3) . Scenarios that rely

reach a net-zero level by 2050, to limit

and if the technical defects in CDR are

dioxide emissions need to be reduced byabout 45% from 2010 levels by 2030 toglobal warming to a rise of 1.5 (IPCC SR1.5

SPM C1). The most effective scenario forgreenhouse gas reduction will be energy

heavily on CDR includes risks. If the CDR

relies heavily on a special technology,

exposed or the society does not accept it,
the plan for CDR unable to be achieved. In

another scenario, because a naturally CO2-system transformation in society. It is

assimilate sink in the marine or terrestrialand sharing economy. We need to increase

overshooting of the target air temperaturea scenario in which energy demand issuppressed by energy-saving technology

the electrification ratio and the ratio ofrenewable energy in electric power to 70-

85% in 2050, and to reduce the coal-fired
power to almost zero (IPCC SR1.5 SPM

C2.2). The investment for the transform ofecosystems is considered to last for a longtime period, it is allowed for temporal(1.5℃ before the Industrial Revolution)(Matsuno et al. 2012). However, when theair temperature exceeds 1.5℃ of global

warming, understanding of carbon cycle

in climate systems, including the carbon
DIWPA News Letter No.43

3

Reportbalance within forests and predicting

cell walls in mesophyll cells, and it will be

For the adequate understanding of

response to environment. In addition, it hasare useful. Conspicuous tree death andp a r a me t er s , s uc h a s t he s ubs t r at eforest dynamics in future, is required tolower the air temperature.

carbon cycle, physiological study andlong-term monitoring of trees and forestsafforestation with prolonged drought haveunable to be ignored when we estimate

CO2 absorption of plants through stomatalbeen recently found that there is a large

interspecific variation in plant physiological

specificity (Sc/o) of photosynthetic enzyme,

been reported in many biomes in the world.

rubisco, in mesophyll cells (Galmés etdeveloped a model with the joint UK landmeasured the specific variations of CO2

For estimating forest change to global

climate change, Eller et al. ( 2020) haveenvironment simulator ( JULES), including

a physiological-based model of plant CO2absorption estimated from stomat al

response to environment by the groupal. 2017 ) . This model in JULES assumes

no interspecific variation in Sc/o. I haveabsorption through stomatal response
under changing environment in drought-

adapted woody plants in the Bonin Islands,Japan (Fig. 1 A and B) . We are found thatof Sperry (Sperry et al. 2016). This model

there is a large interspecific variation invarious plant physiological parameters.

will be due to interspecific variations in

has used constant values obtained frommodel plants in crops, such as tobacco, inFor example, CO 2 diffusion resistancein mesophyll within lamina is assumed

zero. However, CO2 diffusion resistance inmesophyll will be large because of thickA

photosynthetic rates at a given stomatal
opening. The interspecif ic variat ion
CO 2 diffusion resistance in mesophyll
and in Sc/o in photosynthetic enzyme.

Under s t a nd i n g t he s e i nt er s p e c i f ic
variations improves the estimation of plant

BFig. 1. Leaf gas-exchange measurements in drought-adapted trees (A) and the vegetation of a dwarf dry forest (B) in the BoninIslands. The soil is thin and the tree heights are relatively thin at this study site.

4DIWPA News Letter No.43

Report
CO2 absorption through stomatal response

to environmental change in the future.

My study will contribute to improving

the prediction of forest dynamics, carbon
cycle within forests, and CDR in terrestrial
ecosystems. To suppress the increase in

Biological Sciences 88(7): 368–384.
Sperry J. S., Venturas M. D., Anderegg W. R. L.,
Mencuccini M., Mackay D. S., Wang Y. andLove D. M. 2017. Predicting stomatal responses
to the environment from the optimization ofphotosynthetic gain and hydraulic cost. Plant
Cell and Environment 40: 816–830.

air temperature lower at 1.5℃ before theIndustrial Revolution, collaboration withresearchers, policy makers and citizen

is needed through approach based on
not only scientific evidence but also thetransform of energy system in society.

References

Ault T. R. 2020. On the essentials of drought in achanging climate. Science 368: 256-260.
Eller C. B. et al. 2020. Stomatal optimization
based on xylem hydraulics (SOX) improves
land surface model simulation of vegetation
responses to climate. New Phytologist.
Retrieved from https://doi.org/10.1111/nph.16419
Galmés J., Molins A., Flexas J. and Conesa M.
2017. Coordination between leaf CO2 diffusion
and Rubisco properties allows maximizing
photosynthetic efficiency in Limonium species.
Plant Cell and Environment 40: 2081–2094.
IPCC 2018. Global Warming of 1.5°C. An IPCC
Special Report on the impacts of global
warming of 1.5°C above pre-industrial levels
and related global greenhouse gas emission
pathways, in the context of strengthening theglobal response to the threat of climate change,sustainable development, and efforts toeradicate poverty. Retrieved from https://www.
ipcc.ch/sr15/
Komesaroff P. and Kerridge I. 2020. A Continent
Aflame: Ethical Lessons From the AustralianBushfire Disaster. Journal of Bioethical Inquiry:
10–13.
Matsuno T., Maruyama K. and Tsutsui J. 2012.
Stabilization of atmospheric carbon dioxide via
zero emissions--an alternative way to a stableglobal environment. Part 1: examination of thetraditional stabilization concept. Proceedingsof the Japan Academy. Series B, Physical andDIWPA News Letter No.435

New SiteField survey on social behaviors of snakes foraging
on sea turtles in Yambaru National Park,Okinawa Island
Kazumasa Matsumoto

Graduate School of Science, Kyoto University (Japan)

Yambaru National Park, located at theside of the beach is surrounded by steep

Japan on September 15, 2016. There arecoral reefs with a distance of approximately

northern end of Okinawa Island, wasdesignated as the 33rd National Park inapproximately 20 sandy beaches known

as the main nesting sites of green sea
turtles, Chelonia mydas, and loggerhead sea
turtles, Caretta caretta, in the coastal areaof Yambaru National Park in the central
Ryukyu Archipelago. One of these sandybeaches, which is my study site, is locatedadjacent to Oku Village (Fig. 1, 128°17’ E,26°50’ N). On this beach, a unique behaviorof wild snakes is observed. The shore line
length of the beach is approximately 800

m, and the distance from shore line to thebush line is approximately 30 m. The beachmainly consists of fine bioclastic sand suchas coral and shell fragments. The island

Fig. 1. A sandy beach in Yambaru National Park, Okinawa
Island6DIWPA News Letter No.43mountains with an altitude of approximately
70 m, and the sea side is surrounded by
400 m from shore line to reef edge.

On this beach, a unique behavior of wildsnakes is observed. Sea turtles made over 70

nests on the beach from May to September
each year. Each nest contains over 100 eggs

and the hatchlings emerge from the nest
about two months after their oviposition. Atnight, the Ryukyu odd-tooth snake, Dinodon

semicarinatum, appears on the beach to preyon the eggs and the hatchlings.

Dinodon semicarinatum is an endemic

colubrid snake distributed on islands in thecentral part of the Ryukyu Archipelago.

This snake is considered to be a nocturnal

dietary generalist, preying on almost all kindFig. 2. Dinodon semicarinatum swallowing a hatchling ofloggerhead sea turtles

New Siteof small vertebrates. On Okinawa Island andegg chambers of nests. The tunnels fromto feed on sea turtles. Snakes capturesnakes were not always able to reach egg

several islands of the Kerama Group, coastal
populations of snakes have been reported

hatchlings of sea turtles crawling to the seaor burrow the sandy ground to eat eggs in
the nest (Figs. 2 and 3). When several snakes
come to the same nest simultaneously,interactions between individuals sometimes
occur. Such interactions by wild snakes are
generally very difficult to observe in any
species of snakes.

I have conducted field surveys on thebeach by route census and using fixed

infrared video cameras, and observed
foraging behaviors of D. semicarinatum morethan 500 times in total from 2014 to 2019.

Most of the snakes appeared on the beachwere large adult males with a snout-ventthe surface of the beach to the egg camber
remained for several days. Generally, thechambers by burrowing into nests, and its
snout was sometimes injured by its head

poking into the sandy ground. Therefore, thetunnels made by some snakes were used bymany other snakes. Small snakes succeededin foraging on eggs only when using suchtunnels.

Interactions between individuals ofsnakes on nests with the tunnels wererecorded frequently. These interactions

indicate the occurrence of two social traits
based on the behavioral characteristics. First

is “territoriality”: snakes defend the foodresources from other individuals by combat
dance, which is a ritualized fighting (Fig. 4).

length of over 1,200 mm, but a small number

Furthermore, whether a snake challenges

shows a sexual size dimorphism with“dominance hierarchy”: if a snake does notof females and small males also came tosearch for sea turtles (D. semicarinatum

females being smaller than males). However,
only large males were allowed to swallow

hatchlings and burrow deep tunnels toFig. 3. Predation by Dinodon semicarinatum on eggs in anest of sea turtles

against another snake seemed to depend on
the opponent. This implies the presence ofchallenge against an opponent, the former

snake keeps waiting for a few hours near
the nest until the opponent finishes eatingFig. 4. Combat dance by two individuals of Dinodon
semicarinatum

DIWPA News Letter No.43

7

New Siteeggs and leaves the nest. In addition, snakes
seemed to avoid excessive contact withanimals and least social among reptiles.
However, D. semicarinatum that forages onother individuals: when a snake captured asea turtles on the sandy beach on Okinawa

grasping the hatchling with its jaws before

study shows, for the first time, a possibility

hatchling on a nest, the snake immediately
leaves the nest for the bush area while

swallowing it. These behaviors suggest thatD. semicarinatum are highly social.

I have also conducted radio-telemetricsurveys of 18 individuals and tracked their
movements around the coastal area from2016 to 2020. During the nesting season ofsea turtles, the snakes repeatedly moved

back and forth between the beach and themountains. In contrast, the snakes neverIsland, develops highly social behaviors thathave never been reported in snakes. Thisthat snakes have a high degree of sociality,
based on quantitative observations ofinteractions between individuals in thefield. Therefore, the sandy beach in Yambaru

National Park is a unique study site toinvestigate reasons why the solitary snakes
develop social behaviors.

come down to the beach during non-nesting
period. Once snakes came down to thebeach area, they tended to stay near thebeach for several days. In addition, severalsnakes sometimes remained on the sameplace, because there was a nest with thetunnels made by other snakes. Then a small

group was formed temporarily. Whena video camera was set on such a place,the interactions mentioned above wereMail Us!
We welcome your articles,
news or any information related tobiodiversity.
Please send them todiwpa@ecology.kyoto-u.ac.jp

recorded more frequently.

In general snakes are considered solitary
D IW PA O FFI CE

Chairperson
Shin-ichi Nakano
Secretary General
Atsushi Ishida
Secretary	Keisuke Koba		
Shoko Sakai		Noboru Okuda
Assistant Secretary Akiko Seki

Hiroshi Kudo
Shigeo Yachi
Hiromi Uno

Center for Ecological Research
Kyoto University509-3, 2-chome, Hirano, Otsu 520-2113, JAPANTel & Fax : +81-77-549-8238
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