Hosmer's Grove is an example of experimental forestation from Hawaii's territorial days. Located just inside Haleakala National Park

Haleakala National Park

Haleakalā National Park is a United States national park located on the island of Maui in the state of Hawaii. The park covers an area of , of which is a wilderness area...

 near the summit of Haleakala

Haleakala

Haleakalā , or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by the West Maui Mountains.- History :...

 in Maui

Maui

The island of Maui is the second-largest of the Hawaiian Islands at and is the 17th largest island in the United States. Maui is part of the state of Hawaii and is the largest of Maui County's four islands, bigger than Lānai, Kahoolawe, and Molokai. In 2010, Maui had a population of 144,444,...

, Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

, it includes a campsite and several hiking trails.

History

Near the beginning of the 20th century Hawaii's first territorial forester, Ralph Hosmer

Ralph Hosmer

Ralph Sheldon Hosmer was Hawaii's first territorial forester, a contemporary of Gifford Pinchot who was among the group of educated American foresters that organized what is now the U. S. Forest Service...

, imported tree species from around the world in hopes of creating a viable timber industry. He planted stands of pine, spruce, cedar and eucalyptus

Eucalyptus

Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...

, which can still be seen today in the grove. Only 20 of the 86 species introduced survived: those with shallow roots were blown down in storms, others found the soil chemistry or fungi unsuitable for growth or reproduction. A few thrived, escaping from Hosmer's experimental forest. The Mexican Weeping Pine (Pinus patula

Pinus patula

Patula pine, pino patula, pinus patula is a tree native to the highlands of Mexico. It grows from 24° to 18° North latitude and 1800 to 2700 m above sea level. 30 m tall...

), Monterey Pine

Monterey Pine

The Monterey Pine, Pinus radiata, family Pinaceae, also known as the Insignis Pine or Radiata Pine is a species of pine native to the Central Coast of California....

 (Pinus radiata), and eucalyptus have become aggressive invaders and are now recognized threats to the native ecosystems within Haleakala National Park.

The Park

Haleakala National Park

Haleakala National Park

Haleakalā National Park is a United States national park located on the island of Maui in the state of Hawaii. The park covers an area of , of which is a wilderness area...

 was established in 1916 to preserve the native flora and fauna and the outstanding geological resources found within the summit's crater-like depression. Alien plants and animals introduced by humans present a difficult challenge. Today the park's resource managers are reclaiming remnants of the native shrubland around Hosmer Grove by removing thousands of invasive trees and grasses. Without the removal of adult seed-bearing plants and their rapidly spreading seedlings, an alien forest would soon overrun the native shrubland between here and the crater, thereby erasing a fragile Hawaiian ecosystem that has taken millions of years to develop.

The Grove

Forestry - Years of clearing the land for cultivation and ranching have taken their toll. By the early 1900s removal of native forests had led to erosion and drought. Ralph Hosmer

Ralph Hosmer

Ralph Sheldon Hosmer was Hawaii's first territorial forester, a contemporary of Gifford Pinchot who was among the group of educated American foresters that organized what is now the U. S. Forest Service...

 established forest reserves throughout the islands. He experimented with 86 species of trees on Maui

Maui

The island of Maui is the second-largest of the Hawaiian Islands at and is the 17th largest island in the United States. Maui is part of the state of Hawaii and is the largest of Maui County's four islands, bigger than Lānai, Kahoolawe, and Molokai. In 2010, Maui had a population of 144,444,...

, such as eucalyptus

Eucalyptus

Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...

, hoping to improve the watershed, and provide building lumber and fuel for the sugar refineries

Sugar refinery

A sugar refinery is a factory which refines raw sugar.Many cane sugar mills produce raw sugar, i.e. sugar with more colour and therefore more impurities than the white sugar which is normally consumed in households and used as an ingredient in soft drinks, cookies and so forth...

.

Fencing - Near the trail is a fence which was built to keep goats and pigs out of the Park. Because Hawaii is over 2000 miles (3,218.7 km) from the nearest continent, all land mammals found in Hawaii today, except the winged Hawaiian Hoary Bat

Hoary bat

The hoary bat is a species of bat in the vesper bat family, Vespertilionidae. It occurs throughout most of North America and much of South America, with disjunct populations in the Galapagos and Hawaiian Islands...

, have been introduced by people. These alien animals destroy fragile native plants which evolved without the presence of browsing mammals. Look at the native plants around you and try to see them as a pig or goat would. Except for the heath-like pukiawe, most of these plants are easy food for grazing animals. When the ancestors of these plants arrived in Hawaii millennia ago, there were no grazing animals. As plants adapted to their surroundings, they lost defenses they no longer needed, such as poison, thorns, and scent. Fencing protects native plants from grazing pigs and goats.

Gentle thorns - Beneath the alien trees are 'akala (Rubus hawaiensis

Rubus hawaiensis

Rubus hawaiensis, also called the Ākala, is a species of Rubus endemic to Hawaii. It is found on the islands of Kauai, Molokai, Maui, and Hawaii in mesic to wet forest at elevations of...

), or Hawaiian raspberry. In the summer you may find deep-red fruit among the broad leaves. The branches have only small hair - like thorns, having lost the need for defensive thorns, until grazing mammals were brought in.

Native Seeds - You may see berries and seed pods on many of the shrubs along the trail. Although these berries are eaten by the native and alien birds, many of them can make people quite ill. Seeds from these shrubs have trouble sprouting amid the thick alien grasses.

Overlook - As you sit amid the 'iliahi (Santalum haleakalae

Santalum haleakalae

Santalum haleakalae, known as Iliahi in Hawaiian, is a species of flowering tree in the European mistletoe family, Santalaceae, that is endemic to the island of Maui in the Hawaiian Islands, part of the United States...

) and other native shrubs, notice how each has evolved ways of withstanding the often intense conditions on the mountain. The large gnarled trees growing up from the gulch are the native 'ohia, you may see red bottle-brush shaped flowers on them. Hawaiian Honeycreeper

Hawaiian honeycreeper

Hawaiian honeycreepers are small, passerine birds endemic to Hawaii. Some authorities still categorize this group as a family Drepanididae, but in recent years, most authorities consider them a subfamily, Drepanidinae, of Fringillidae, the finch family...

s dip their curved beaks into these flowers for nectar, and in doing so pollinate the flowers. This active interdependence highlights the need for preserving all elements of a forest, and not just the tree.

Germination - Some seeds from native shrubs have tough outer hulls and botanists were unable to make them germinate. But a researcher found that from the dropping of the chukar

Chukar

The Chukar Partridge or Chukar is a Eurasian upland gamebird in the pheasant family Phasianidae. It has been considered to form a superspecies complex along with the Rock Partridge, Philby's Partridge and Przevalski's Partridge and treated in the past as conspecific particularly with the first...

 partridge and the Chinese ring-neck pheasant seedlings emerge. These alien birds appear to be benefiting the native plants by breaking down the seed hull, and taking the place of a native seed eating bird which is probably now extinct. However, chukar and common pheasant

Common Pheasant

The Common Pheasant , is a bird in the pheasant family . It is native to Georgia and has been widely introduced elsewhere as a game bird. In parts of its range, namely in places where none of its relatives occur such as in Europe , it is simply known as the "pheasant"...

 can adversely impact native bird populations by serving as disease reservoirs.

Adaptation - The Hawaiian Islands

Hawaiian Islands

The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...

 emerged from the sea millions of years ago and a colonizing plant managed to become established once every 100,000 years. Plants got to Hawaii via the three W's: wind, bird wings or waves. After arriving, they evolved to take advantage of a variety of new habitats. A single colonizing ancestor often changed or developed into many new endemic species; this is known as adaptive radiation. There are more than 10,000 species of endemic Hawaiian plants, birds and insects. But sadly, with this great diversity comes great loss. Nearly 75 % of our nation's documented plant and bird extinctions were endemic Hawaiian species.

The Silver Geranium - Hinahina, the silver geranium, can be seen growing along the trails at Hosmer's Grove. With its silvery tridentate leaves and small whitish flowers, hinahina is endemic to Haleakala. It is found nowhere else on earth. Its silver, slightly tomentose (hairy) leaves protect it from the relentless sun, wind, and extreme temperatures found near the summit.

Biodiversity - The native shrublands support a large diversity of life, unlike the understory of this pine and eucalyptus forest. Notice as you walk under the Norway spruce

Norway Spruce

Norway Spruce is a species of spruce native to Europe. It is also commonly referred to as the European Spruce.- Description :...

 ahead that there are few other plants which can survive being deprived of sunlight and inhibited by plant chemicals.

The Hike

This half-mile trail will lead you on a 30 minute walk through one of the biological battlegrounds of the Park. The trail begins in the shade of a 20th century alien forest and ends in native Hawaiian shrubland that looks as it did centuries ago. Numbered posts and plaques are found along the trail.

This trail continues on a l/4 mile loop into the native shrubland; turning right will take you back to the parking lot. Looking across the gulch you see a mixture of native trees, shrubs and ferns. The larger 'ohia (Metrosideros polymorpha

Metrosideros polymorpha

The ōhia lehua is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations, and much smaller when growing in boggy soils or on basalt...

), koa

Koa

Acacia koa is a species of flowering tree in the pea family, Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaii, Maui and Oahu...

, and olapa are still found in remote gulches, but covered much of the lower mountainside just a century ago. The native forests are a vital part of the watershed, drawing clouds and rain to the mountain, and controlling erosion.

From here the trail leaves the shrubland and returns through Hosmer Grove to the parking area.

External links

• Haleakala National Park
• "Exceptionally Exotic" Article about Hosmer's Grove by Bill Harby. Maui No Ka 'Oi Magazine
  Maui No Ka 'Oi Magazine
  Maui Nō Ka Oi Magazine is a bi-monthly regional magazine published by the Haynes Publishing Group in Wailuku, Hawaii.The phrase Maui nō ka ʻoi means "Maui is unparallel" in the Hawaiian language. Maui Nō Ka Oi Magazine features stories relating to the culture, art, dining, environmental issues,...
  
  Vol.8 No.2 (July 2002).