International Symposium: Hawai'i August 4-7, 2012

The international conference “Vulnerable islands in the sky: management of tropical island alpine and sub-alpine ecosystems” was hosted in Hawaii (Big Island), Waimea, from August 4-7^th 2012. The University of Hawaii at Hilo (UHH), the office of Mauna Kea management and the Gordon and Betty Moore foundation supported this conference.

Thirty papers were presented and almost 50 people gathered at HPA Waimea for this symposium. I report below some highlights of what we talked about; linking science and management was central in the discussion.

Donald Straney (UHH chancellor), in the welcoming remarks, highlighted the responsibility of the university for managing these alpine mountain ecosystems and the unique opportunity of gathering scientists of high islands in the world for replicated systems.

Session 1: Tropical Mountain Climate Change

In his introductory talk “Losing the high ground: rapid transformation of tropical island alpine and sub-alpine environments”, James Juvik and co-authors raised the fact that the temperature inversion layer found in most oceanic islands with trade winds, has a major impact on increasing aridity at the summit areas. 

Pix: Sea of cloud on Mauna Loa (4170 m), from the trade wind inversion (TWI) layer

This phenomenon has dramatic effect on the water balance of these high altitude ecosystems. Similarly, Patrick Martin (Colorado University) showed for the Dominican Republic on a 10-year survey a rise of temperature and specifically an increase in the frequency of the inversion temperature layer. From his HALENET network climatic data sets (24 years recordings), Thomas W. Guimelluca (University of Hawaii, Manoa) could enounce with confidence an increase of temperature in the future, with less confidence a lower amount of precipitation, higher solar radiations and less clouds.

Pix: Climatic station on Mauna Kea

Consequences of increased aridity is already noticeable on the flanks of Mauna Kea, Paul Krushelnyky (University of Hawaii, Manoa) gave the example of climate associated population declines of the iconic endemic silversword, associated with continued warm and dry conditions added to damage by introduced ungulates and human vandalism.

Pix : Endangered silversword: Argyroxiphium sandwicense ssp. macrocephalum on Mauna Kea

In his talk, Henri F. Diaz (NOAA) specified that warmer oceans lead to enhance hydrological cycle as an increase of latent heat input to the atmosphere. Data from the last 80 years indicate enhanced upper elevation warming include a reduction in the frequency of occurrence of freezing temperature in the upper slopes of the higher terrain in Maui and Big island (Hawai’i archipelago). Michael Prentice (Indiana University) and Geoffrey Hope (Australian National University) supported this result, by reporting the glacier recession in Papua and New Guinea provinces, as well as the sensitivity of the alpine vegetation to climatic and anthropogenic disturbances. G. Hope highlighted the use of paleoecology to reconstruct vegetation dynamics, also emphasized by Shelley Crausbay (Colorado University) in session 2, on her study case on a glacier Lake of Haleakala volcano in Hawai’i. To end the first session Wouter Buytaert (Imperial College) gave an overview of the importance of tropical alpine grasslands for ecosystem services including water supply, biodiversity and carbon storage, with the example of the Paramó in the Andes.

Session 2: Evolution in Mountain Environments

Oceanic island summits offer a high degree of endemic species especially for plants. Mountains act as islands within islands, for space that has been already isolated. In his paper, Manuel Steinbauer (University of Bayreuth) related space and the geological evolution of island archipelagos to the diversity of high elevation ecosystems, and took the example of single island endemics, which increase with elevation. José Maria Fernandez Palacios (University of La Laguna) accentuated the effect of erosion (habitat history) on those sub-alpine island ecosystems. José Maria reminded us that summit biota frequently displays a very high endemism, which may originate from dispersal from other close summit ecosystems during peak period (multiple summit endemics), when a dispersal window remains open for pre-adapted summit biota, or more usually from the colonisation of the summits and later evolution to the new conditions from low or mid-altitude generalist species of the same island (single summit endemics). In the “No Way Out” scenario, when peaks are absent, the disappearance of summit ecosystem implies the extinction or extirpation of their competitive species. Allen Allison (Bishop Museum) gave the only example on animals, with the high altitude herpetofauna of New Guinea. Thirty-one species of amphibians and reptiles found above 2000 m are related to groups inhabiting adjacent lowlands and most are confined to single mountains summits suggesting localized evolution for amphibians (lizards and frogs).

In his talk, Jonathan Price (University of Hawai’i, Hilo) examined how biodiversity originates in tropical island ecosystems from three distinct mechanisms (1) single species colonizer like the silverword species (2) colonization from pre-adapted species (Sophora sp.) (3) shift to alpine. He looked at the relative contribution of colonization, adaptation and speciation on three archipelagos (Hawaii, Canarias and Mascarenes). He found that Hawai’i hosts the highest number of endemic species, which can be related to extreme isolation of this archipelago) and that most of these islands are endemic originate from pre adapted taxa. Community assembly has therefore been shaped somewhat by habitat filtering in these island systems.

Session 3: Ecosystem Dynamics

This session was diverse and varied from studies on tree line shifts in Taiwan from Sarah Greenwood and Alistair Jump (University of Stirling), ecology, altimontane bryophyte diversity and distribution, effect of herbivores and fire on diversity in Canarias from Severin Irl (University of Bayreuth), conservation and management in West Africa (Drew Cronin, Drexel University) and paleoecology (Shelley Crausbay, University of Colorado).

I presented the functional diversity structure of bryophyte communities along the upper elevation gradient of the Piton des Neiges volcano showing that the functional diversity index based on 8 traits decreased with altitude, supporting the hypothesis that increased environmental adversity leads to an homogenization of traits for this sub alpine bryophyte communities indicating also that these community may be resilient to perturbations.

Fabien Anthelme (Institut de Recherche et Développement) presented his work on the Andes, considering alpine islands are summits surrounded by continental lowlands. He documented, from 24 literature sources, the percentage of species restricted to alpine environments, the isolation by spatial distance and by size of alpine environments for plants and invertebrates. Among his results, he showed that tropical alpine environments for these organisms behave distinctly from their counterparts in extratropical alpine environments.

Session 4: Mauna Kea

James Juvik, in his conference introduction, raised concern about the Mauna Kea volcano (4169 m), which is at the same time considered as a sacred mountain by the native community but is also used by scientists (astronomy…), hunters, hikers, these users share a small area with high human impact.

Pix: James Juvik holding some very hard rock obsidian, which the polynesians used as an adze. This hard rock comes from the previous glacier that existed on the highest part of Mauna Kea above the basalt. So Polynesians were taking a long journey to collect this rock and purify and heal in the lake Waiau (below); left Stéphanie Nagata (OMKM)

This last session of the symposium was about the Mauna Kea volcano, Stéphanie Nagata (Head of the Office of Mauna Kea Management) reviewed the 12 years of community-based management of this high system. Grant Gerrish (University of Hawai’I, Hilo) described this alpine vegetation and habitat types. Jesse Eiben, entomologist, showed how research program centred on a single alpine endemic insect the Wekiu bug (Nysiuswekiucola) informs ecosystems level resource management. This bug is found only on the summit of Mauna Kea and is highly dependent on wind-blown, gravity-deposited, insect prey from lower elevation.

To end this conference, discussion was lead on the management of the high alpine zone of tropical oceanic islands especially on the effect of tourism and scientific activity. Sonia Juvik in her paper “ In search of a post modern paradigm for land use management on tropical high mountains” gave her analysis on the Mauna Kea case study.

Recommendations from the representatives of the different islands present at this symposium were gathered into three main points:

1) Public use issues

2) Science management interface

3) Long term environmental monitoring.

There was a strong will from the audience to build local expertise, to initiate comparative studies on the tropical alpine environments and to consolidate this network, with the possibility to set a future meeting in the Canaries.

This symposium was punctuated with social events including Hapuna Beach swim and barbecue, a night at Hale Pohaku at the astronomy centre where we did star gazing and were granted to see Saturn’s rings very clearly. The next morning we were very lucky to go to the Mauna Kea summit and hiked to Lake Waiau. 

Pix: Summit of Mauna Kea 

Pix: The monitored Lake Waiau (3979 m) utilizing 3D technological approaches by Donna Delparte's team (UHH). Concern about declining lake levels has created the stimulus for this study to use techniques to monitor lake level without disturbing the lakes.

To end the conference we attended a Luau in Kona, which is a celebration of South Pacific culture rythmed by Polynesian dances from Hawaii, Samoa, Fiji, Tahiti...

Pix: Luau in Kona

With another six attendees we embarked on a two day- post conference field trip with John Delay (PhD student at the University of Hawaii). We had the opportunity to visit and learn more about the different habitats on Big Island (Kipukas, lava tubes, Akaka waterfalls…).

Pix: the crew of the post conference field trip

Pix: Waipi'o coast

Pix: Akaka falls

Pix: Acacia koa, closest relative is Acacia heterophylla in Réunion island.

Pix: Metrosideros polymorpha, endemic pioneer tree on lava flows

Pix: Current eruption at Mauna Loa volcano

I feel very lucky to have the opportunity to take part to this symposium and wish to thank the organizing committee for the excellent job they did to assemble this program, the time and energy they dedicated to make this symposium inspiring and enriching.

For those who would be interested to learn more, the proceedings of this symposium will be featured in the journal of Arctic, Antarctic and Alpine Research.

Mahalo!

Claudine Ah-Peng

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