Hahai nō ka ua i ka ululāʻau
The Rain Follows the Forest
“Not enough rain and not enough water in the streams are great evils”.
“It appears to me to be unnecessary to again go deeply into the theory of the relation between forests and rainfall when all intelligent and observing people admit that the decrease or increase of rainfall goes pari passu (‘hand-in-hand’) with the decrease or increase of the forests.”
“The forest, which not only produces rain, but also retains the rainwater, holding it among its leaves and branches, its undergrowth, its myriads of roots and rootlets and its fallen debris, letting the rainwater trickle down slowly to the water streams and keeping them supplied for a long time”.
“(T)hat forest is not there. Rain pours down, the water rushes in torrents through the streams to the sea and soon after everything is dry again.” (Gjerdrum to HSPA, 1897)
“The ultimate success of forestry in Hawaiʻi depends on the continued cooperation of individuals and private corporations with the Territorial Government.” (Board of Agriculture and Forestry, December 31, 1907)
In the early-1900s, Mānoa Valley’s lower slopes were stripped of their native vegetation by excessive agricultural cultivation and the overgrazing of cattle.
Without healthy forest cover, rainwater flowed to the ocean rather than recharging the ground water table, Hawaiʻi’s primary source of drinking water. This loss was of special concern to the Hawaiian Sugar Planters’ Association (HSPA,) because sugar required great quantities of water.
In 1918, HSPA established Mānoa Arboretum in order to develop methods of watershed restoration, test tree species for reforestation and collect plants of economic value.
They put Dr Harold L Lyon, a young botanist from Minnesota, in charge of 124-acres at the back of Mānoa Valley. He was, at the same time, superintendent of the Territory’s Department of Botany and Forestation.
The site lies in the ʻili (land division) of Haukulu and ʻAihualama, in Mānoa. Several man-made features, including stone platforms, loʻi and the occurrence of many Polynesian-introduced plants note early use of the site.
One of Dr Lyon’s tasks at the arboretum was to identify trees suitable for rebuilding watersheds. Lyon observed that the adverse conditions of soil created from volcanic rock erosion appeared to affect the growth, survival and eventual death of many tree species.
He also noted that native plants did not thrive in areas that were previously trampled by cattle and other animals. The experiment station’s goal was to find trees that not only could survive in soil containing volcanic rock components, but also would comprise efficient water-conserving forests.
Mānoa Arboretum was a test site to evaluate trees that could be used for reforestation throughout the islands, and to test sugarcane seedlings. The test site became the basis of the Mānoa Arboretum.
Tree-planting was a coordinated effort involving Lyon, HSPA and Territorial Forestry under the direction of Ralph Sheldon Hosmer, the Territorial Forester. The early foresters planted many types of trees on an experimental basis, but concluded that native species were of limited utility and turned largely to introduced species for large-scale reforestation efforts. (Woodcock)
Lyon concluded that healthy forests should be preserved, that heavily damaged native forests could not recover on their own, and that damaged watersheds could be restored with introduced plants. Planting began in 1920, and was essentially completed by 1945.
“As an influential board member on the Agriculture and Forestry Commission, Harold Lyon succeeded in persuading the Territorial Commission to import seed of a vast number of alien tree species. … nearly 1,000 alien species were outplanted in Hawaiʻi forest reserves.” (Mueller-Dombois)
Various trees and plants were imported from diverse areas of the world including Madagascar, Australia, India, Brazil, the Malay states, China, the Philippines, southern Europe, the East Indies, the West Indies, New Zealand, Central America and South Africa. Trees that successfully survived the Mānoa Valley soil conditions and promoted water conservation were then widely planted throughout the arboretum
Eucalyptus species, silk oak, paperbark and ironwood were the most frequently planted trees due to their fast growth and their resistance to adverse environmental conditions. However, these very qualities, as well as their ability to seed profusely, would lead to some species such as tropical ash and albizia. (Iwashita)
The number of trees planted rose to many millions by the 1930s, when the Civilian Conservation Corps (CCC) was available for planting. From 1935 to 1941, with the help of the CCC, an average of close to two-million trees were planted per year in the forest reserves.
Lyon envisioned the plantations as a buffer zone that would be established between the remaining native forests and the lower-elevation agricultural lands to protect the native forests and perform the functions (maintaining input of water to aquifers.)
This large-scale attempt to engineer nature was probably the largest environmental project ever carried out in the islands. Forestry introductions have been a significant contributor to Hawaiʻi’s alien-species crisis, with many of these tree species now problem invasive species. (Woodcock)
In his 1949 annual report to the HSPA entitled, ‘What is to be the fate of the arboretum?,’ Lyon declared the Mānoa Arboretum’s mission to test new plant introductions to be essentially complete; he believed that the HSPA should not remain the arboretum’s custodian.
On July 1, 1953, HSPA conveyed the Mānoa Arboretum to the Board of Regents of the University of Hawaiʻi. The regents were individually entrusted with the fiduciary duty of maintaining the arboretum. In 1962, the Board of Regents transferred the arboretum to the University of Hawaiʻi.
Dr. Lyon remained with the arboretum as its first director under the regents’ and university’s stewardship. After Dr. Lyon’s death in 1957, an advisory committee directed the arboretum until 1961, when Dr. George Gillette assumed the directorship on a part-time basis.
When Dr. Lyon died, the Board of Regents renamed the facility the Harold L. Lyon Arboretum (Lyon Arboretum) in honor of the man so closely associated with its growth and fruition.
In the early years, eight cottages were built on the arboretum site for staff use. The cottages were given alphabetical designations, beginning with cottage “A” at the foot of the hill leading into the arboretum site and ending with cottage “H” at the top of the hill. Lands surrounding the cottages were planted with sugar cane. Dr. Lyon also erected an orchid greenhouse between cottages “F” and “G,” which is still used today.
Cottage “H” was expanded over time and is now the main center of the Harold L. Lyon Arboretum, housing offices, a reception area, an educational office, and a book and gift shop.
Forestry, Forest Reserves, Watershed Partnerships, invasive species and related water and habitat concerns were very much a part of daily activities when I was at DLNR.
Today, I am honored and proud to serve as a director on the Hawaiʻi Forest Institute, an organization dedicated to promote the health and productivity of Hawaiʻi’s forests, through forest restoration, educational programs, information dissemination and support for scientific research.