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Alpine Hawai'i

Alpine Hawai'i

Alpine Hawai’i

Images from : https://vimeo.com/63766463 Alpine Hawai’i

Two high have on their summits, characterized by high winds and cold, dry air

Summits shaped by glacial activity during pleistocene (geological epoch from 2,588,000 to 11,700 years ago, spanning recent period of repeated glaciations)

Alpine Hawai’i – Big Island Two volcanic summits nearly 14,000 feet:

Mauna Loa – 13,676 feet

“Long ”

Mauna Kea – 13,796 feet “White Mountain”

Summit of covered in snow Alpine Hawai’i – One volcanic summits nearly 10,000 feet:

Haleakala – 10,023 feet “house of the Sun”

The volcanic plateau around the Haleakala crater (2,750 m) Alpine Last glacial period (80 – 10 Kya)

Mauna Kea - Glaciers formed about 70,000 years ago and from approximately 40,000 to 13,000 years ago

At their maximum extent, glaciers extended from summit down to between 3,200 and 3,800 m elevation (10,500 and 12,500 ft)

Glaciers eroded the mountain and created deposits

Mauna Loa - If glacial deposits were formed, they have long since been buried by younger flows

Glacial and Deposits Glacial deposits ion Mauna Kea: terminal ("m") and till ("w")

Glacial Erosion and Deposits Terminal : Forms at snout of a , marking its maximum advance

May coincide with the end moraine

End moraine marks present glacier boundary

Glacial Till: Unsorted glacial sediment - sharp Coarsely graded and heterogeneous

Glacial Lakes Mauna Kea is home to Lake Waiau, the highest lake in the Pacific Basin at an altitude of 3,969 m (13,022 ft)

Lies within the Puʻu Waiau and is the only alpine lake in Hawai’i

Very small and shallow lake, with a surface area of 0.73 ha (1.80 acres) and a depth of 3 m (10 ft)

Glacial Lakes Lake Waiau - of the lake sediments indicates it was clear of ice 12,600 years ago.

Usually, permeable Hawaiian prevent lake formation by water .

Two explanations:

- sulfur-bearing steam altered volcanic ash to low-permeability clays

- explosive interactions between rising and ground / surface water formed fine ash with reduced permeability

Alpine Weather Conditions Wide temperature range: from -2 to 20 deg. C.

Daily variation (min to max: -2 to 14 deg. C.) Seasonal variation (max: 4 to 18 deg. C.)

Alpine Weather Conditions

- Snow and ice

- Strong winds (to 70 mph)

- Low oxygen concentrations (50% sea level)

- Very low humidity (~10%)

- Very strong UV radiation

Alpine Hawai’i Vegetation

In spite of nightly freezing temperatures and intense ultraviolet radiation, lichens and mosses dot this aeolian (wind-influenced) ecosystem

Lichens: Composite organisms consisting of a fungus (mycobiont) and a photosynthetic partner (photobiont or phycobiont) growing together in a symbiotic relationship

The photobiont is usually either a green alga (Trebouxia) or cyanobacterium (Nostoc) Alpine Hawai’i -

Metrosideros polymorpha ("multi-statured“) of family Myrtaceae, stunted by dry conditions, and growing on lava flow at (Mauna Loa, 2700 m)

Tetramolopium alpinum () schlerophyll vegetation (Haleakala, 2750 m)

Dubautia menziesii (Asteraceae) succulent vegetation (Haleakala, 3050 m) Alpine Hawai’i - Insects

Alpine summit zone inhabited by at least 12 cold-hardy native insects and other arthropods

Unique, flightless wëkiu bug (), discovered in 1979 on the summit cone of Mauna Kea

“Wëkiu” means “summit” in Hawaiian

This predator – size of a grain of rice – is dependent on fresh insects blown up the mountain from lower elevations

It hunts for prey lodged in scoria and crevices, and waits along the edges of snowmelt for its meals Alpine Hawai’i - Insects

Lab studies revealed amazing blood chemistry that kept wëkiu from freezing until 1.4° F (-17 deg. C)

A sister species, Nysius a‘a, also sucks blood from insects, is found only on Mauna Loa

Alpine Hawai’i – Other Arthropods

The omnivorous cutworm caterpillars; are moth larvae that hide under soil during day, coming out in dark to feed

voracious Lycosa wolf spiders

and centipedes (Lithobius species)

… that prey on insects Alpine Hawai’i - Insects

Alpine Hawai’i - Insects

Springtails (Entomobrya kea) - tiny insects that jump using built-in springs on their tails

Three species at the 13,800-foot cinder-cone summit of Mauna Kea

Most species have an abdominal, tail-like appendage, the furcula, that is folded beneath the body to be used for jumping when threatened. It is held under tension and when released, snaps against the substrate, flinging springtail into air Alpine Hawai’i - Plants

Argyroxiphium sandwichense (Asteraceae), the "silversword", 's giant rosette

Covering with grey hair – high albedo protects from strong sunshine Silverswords Originates from the tarweed subtribe (Madiinae) of sunflower tribe (Heliantheae) in aster family (Asteraceae)

Hawaiian consists of about 30 species in three genera (, ,)

Species exhibit extraordinary range of anatomical, morphological, and ecological adaptations; despite being very closely related as evidenced by molecular studies Silverswords Argyroxiphium genus – high elevation specialists

- Largest species (A. sandvicense) split into two subspecies:

A. sandvicense macrocephalum East Maui (Haleakala)

A. sandvicense sandvicense Island of Hawai’i (Mauna Kea)

Silverswords

- A. sandvicense - split into two subspecies:

Silverswords

- Highly restricted (A. kauense): From Mauna Loa’s slopes

Inhabits much broader range of habitats, and is found in montane shrubland, bogs, open mesic forest

Threatened by damage from , , and

Three known occurrences, for a total of 1000 individuals

Listed in the U.S. E.S.A.

Silverswords

- Highly restricted A. kauense: Mauna Loa’s slopes

Silversword Silverswords cannot produce fertile without cross-pollination. Therefore, depend on insect

Native moths, flies or bees travel in a circle around the perimeter of the blossom gathering pollen

Silverswords subject to Allee effect, whereby individuals experience reduction in pollination and production when the populations are small … or sparse

Robert Robichaux pollinating a silversword Silversword Pollination

Measured pollen limitation and self-incompatibility in this species through two pollination experiments conducted over multiple years

Examined temporal variation in reproductive success of Haleakala silversword over five years, to determine: if plants flowering out of synchrony with most of the population (i.e., during low flowering periods) exhibit lower percent seed set than synchronously-flowering plants (i.e., during high flowering periods)

(Forsyth 2003) Silversword Pollination

Number of flowering plants varied greatly among years, as did reproductive success

Percent seed set was significantly correlated with number of plants flowering annually, such that plants flowering in high flowering years (1997, 2001) exhibited higher percent seed set than plants flowering in low flowering years (1998, 1999, 2000) (Forsyth 2003) Silversword Pollination

In 3-year pollen limitation study, plants flowering asynchronously were pollen-limited, whereas plants flowering synchronously were not

Result suggests pollination is strongly density-dependent

(Forsyth 2003) Silversword Pollination

In another 2-year pollen limitation study, plants with cross-pollination did much better than plants with self-pollination

Suggests results this species is strongly self-incompatible

(Forsyth 2003) Silversword Life History

Silverswords live for 10 to 50 years. At end of their life, they grow flowering stalk that can grow over 6 feet tall within a few weeks, and produce up to 600 heads.

After being pollinated, the silversword dies.

Seed germination affected by environmental conditions:

Optimal in moist and shady Conditions (“nursery effect”)

Higher ability to germinate for seeds in flower stalks

In mesic environments, grasses competed with seedlings

(Walker & Powell 1995) References

Forsyth, S.A. (2003). Density-dependent seed set in the Haleakala silversword: evidence for an Allee effect. Oecologia 136(4):551-557

Walker, L.R., and Powell, E.A. (1995) Factors Affecting Seed Germination of the in Hawai'i. Pacific Science 49(3):205-211

He’eia Fish Pond (Sat. April 23)

Please bring following items to the workday:

Covered Shoes or Tabis (mandatory to participate)

Clothes you don’t mind getting dirty and wet

Hat and Sunscreen, Water Bottle

Optional: Towel, Dry Clothes

NOTE: Work from ~ 9 to ~ 11 (done by 12) They will feed us lunch (not veggie) He’eia Fish Pond– Saturday April 23

Meet at HLC at 8.00 OR at the site:

46-077 Ipuka Street

http://paepaeoheeia.org/

What’s Next ? • Final Lecture – April 25th: Not included in Exam

• Midterm II – April 27th: Includes Today’s Lecture

• Final – May 2nd 8:00 – 9:45 Symposium (In Class)

- Group Oral Presentation (5 groups) 15% - 15 minute presentation - 5 minutes questions / answers

- Individual Extended Abstract 10%

• Individual Take-Home Final – May 6th (by email) 10%

- Self-evaluation & Project questions

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