Hosmer's Grove facts for kids
Hosmer's Grove is a special forest area in Haleakalā National Park on the island of Maui, Hawaii. It's located high up near the top of the Haleakalā volcano. This grove shows how people tried to grow new types of trees in Hawaii a long time ago.
Today, Hosmer's Grove has a campsite and fun hiking trails. It's also a great spot for people who love birds. Many unique Hawaiian honeycreepers live here. These include the Iiwi, Apapane, Hawaii Amakihi, and the Maui Alauahio.
Contents
The History of Hosmer's Grove
How the Grove Started
Hawaii's first forest expert was named Ralph Hosmer. In the early 1900s, he brought tree seeds from all over the world to Hawaii. He hoped to grow trees that could be used for wood.
In 1927, Ralph Hosmer started planting different trees in this area. He planted types of pine, spruce, cedar, and eucalyptus. You can still see some of these trees in the grove today.
What Happened to the Trees
Out of 86 types of trees Hosmer planted, only 20 survived. Some trees had shallow roots and were blown over in storms. Others did not like the soil or the fungi in Hawaii.
A few types of trees grew very well. They spread outside of Hosmer's experimental forest. These include the Mexican weeping pine, Monterey pine, and eucalyptus. These trees are now a problem. They are taking over native plants in Haleakalā National Park.
Protecting Haleakalā National Park
Why the Park Was Created
Haleakalā National Park was created in 1916. Its main goal is to protect Hawaii's native plants and animals. It also protects the amazing volcano landscapes.
Challenges for the Park
Plants and animals that humans brought to Hawaii cause big problems. These "alien" species can harm the native ones. Park managers are working hard to save the native areas around Hosmer Grove.
They are removing thousands of invasive trees and grasses. If these alien plants are not removed, they would quickly take over. This would destroy a special Hawaiian ecosystem. This ecosystem took millions of years to develop.
Exploring the Grove
Why Forests Are Important
For many years, people cleared land for farms and ranches. This damaged the native forests. By the early 1900s, removing trees led to soil washing away and dry conditions.
Ralph Hosmer created forest reserves across the islands. He tried planting 86 types of trees on Maui. He hoped these trees, like eucalyptus, would help collect water. They were also meant to provide wood for building and for sugar refineries.
Fences Protect Native Plants
Near the trail, you will see a fence. This fence was built to keep goats and pigs out of the Park. Hawaii is very far from any other large land. So, almost all land mammals in Hawaii were brought by people. The only native land mammal is the Hawaiian hoary bat.
These introduced animals harm fragile native plants. Hawaiian plants grew for millions of years without animals that eat them. Look at the native plants around you. Imagine if you were a pig or a goat. Most of these plants are easy to eat.
When these plants first arrived in Hawaii, there were no grazing animals. So, plants lost their natural defenses. They no longer needed poisons, thorns, or strong smells. Fences help protect these native plants from grazing pigs and goats.
Hawaiian Raspberry: Gentle Thorns
Underneath the introduced trees, you might see 'akala. This is the Hawaiian raspberry (Rubus hawaiensis). In the summer, you might find deep-red fruit on its broad leaves.
The branches of 'akala have only small, hair-like thorns. They lost the need for strong thorns because there were no grazing animals. This changed when grazing mammals were brought to Hawaii.
Native Seeds and Birds
You might see berries and seed pods on many shrubs along the trail. Native and introduced birds eat these berries. But many of them can make people very sick.
Seeds from these native shrubs have trouble growing. They struggle to sprout among the thick, introduced grasses.
The Overlook and Native Trees
As you sit among the 'iliahi (Santalum haleakalae) and other native shrubs, notice how they survive. Each plant has found ways to handle the strong mountain conditions.
The large, twisted trees growing from the gulch are native 'ohia trees. You might see red, bottle-brush shaped flowers on them. Hawaiian honeycreepers use their curved beaks to drink nectar from these flowers. As they do this, they help pollinate the flowers. This shows how important it is to protect all parts of a forest, not just the trees.
How Seeds Germinate
Some native shrub seeds have very tough outer shells. For a long time, scientists could not make them grow. But a researcher found something interesting. Seedlings started to grow from the droppings of the chukar partridge and the Chinese ring-neck pheasant.
These introduced birds seem to help native plants. They break down the tough seed shells. They might be taking the place of a native seed-eating bird that is now extinct. However, chukar and common pheasant can also harm native birds. They can carry diseases that affect native bird populations.
Plant Adaptation in Hawaii
The Hawaiian Islands rose from the ocean millions of years ago. A new plant managed to arrive and grow here only about once every 100,000 years. Plants reached Hawaii in three main ways: by wind, on bird wings, or carried by ocean waves.
After arriving, these plants changed to fit many new habitats. One single ancestor plant often developed into many new unique species. This is called adaptive radiation. Hawaii has over 10,000 species of unique plants, birds, and insects.
Sadly, with this great variety comes great loss. Almost 75% of all plant and bird extinctions in the United States were unique Hawaiian species.
The Silver Geranium
Hinahina, or the silver geranium, grows along the trails at Hosmer's Grove. It has silvery leaves with three points and small whitish flowers. Hinahina is found only on Haleakala. It grows nowhere else on Earth.
Its silver, slightly hairy leaves protect it. They shield it from the strong sun, wind, and extreme temperatures near the volcano's summit.
Biodiversity in the Grove
Native shrublands support many different kinds of life. This is very different from the ground under a forest of pine and eucalyptus. As you walk under the Norway spruce trees, notice how few other plants can survive there.
These introduced trees block sunlight. They also release chemicals that stop other plants from growing.
Hiking the Trail
This trail is about half a mile long. It takes about 30 minutes to walk. It leads you through an area where native and introduced plants are battling. The trail starts in the shade of the introduced forest. It ends in native Hawaiian shrubland, which looks as it did hundreds of years ago. You will find numbered posts and signs along the trail.
This trail continues on a quarter-mile loop into the native shrubland. If you turn right, it will take you back to the parking lot. Looking across the gulch, you will see a mix of native trees, shrubs, and ferns.
Larger 'ohia (Metrosideros polymorpha), koa, and olapa trees are still found in remote gulches. But just a century ago, they covered much of the lower mountainside. These native forests are very important for the watershed. They help bring clouds and rain to the mountain. They also help control soil erosion.
From here, the trail leaves the shrubland. It then returns through Hosmer Grove to the parking area.
