Understanding Reforestation
What is reforestation? Are there different methods? What costs and benefits are involved? In this blog, we will break it down, share what we have observed and learned, and address some of the most common questions we’ve received over the years.
A Legacy of Conservation
The Kona Cloud Forest Sanctuary was founded in 1982 by Norman Bezona, a passionate forest advocate and my grandfather. Throughout the 1900s, during his global explorations of forest ecosystems, tropical agriculture, and human cultures, Norman observed alarming rates of deforestation worldwide, including in his homeland of Hawaii. Witnessing the rapid destruction of forests deeply affected him, leading to his lifelong commitment to conservation.
The History of Deforestation in Hawai’i
Hawai‘i’s native ecosystems have been influenced by human impact since the first voyagers arrived, with deforestation intensifying after Western explorers and settlers reached the islands in the late 1700s. In 1793, Captain George Vancouver gifted cattle to King Kamehameha I to provide a sustainable food source and bolster the local economy. To protect the growing herds, a kapu (taboo) was placed on killing the cattle, allowing their numbers to multiply. However, as the cattle population expanded, overgrazing and habitat destruction followed, leading to widespread ecological change.
By the late 19th and early 20th centuries, ranchers introduced non-native grasses such as Guinea grass (Megathyrsus maximus) and molasses grass (Melinis minutiflora) to improve cattle forage. While intended to enhance pasture quality, these fast-spreading grasses quickly became invasive, outcompeting native vegetation and fundamentally altering Hawaii’s landscape.
The expansion of sugarcane and pineapple plantations during this period further contributed to deforestation. The Island of Hawaii, in particular, experienced some of the most severe impacts. Lowland forests of endemic trees like koa, ʻōhiʻa lehua, and sandalwood were systematically logged and cleared. Ranching operations transformed large swaths of land into pasture, leading to habitat loss and the encroachment of invasive species.
Challenges in the Kaloko Mauka Cloud Forest
In the mid-1900s, Kaloko Mauka, the high-elevation region of the Kaloko ahupuaʻa where the Kona Cloud Forest Sanctuary is located, faced significant deforestation. As the area was subdivided into agricultural plots, new landowners often cleared their properties without ecological consideration—a practice that unfortunately continues today.
Concerned by these developments, Norman initiated community workshops to educate residents about the importance of this Hawai’i cloud forest ecosystem and the delicate balance between forest health, climate stability, and the water cycle connecting the mountain to the ocean, and everything in between. These educational efforts have become a cornerstone of our mission, emphasizing the role of trees in maintaining climate stability, supporting cloud formation, and replenishing the aquifer that supplies water to West Hawaii.
The Promise of Hybrid Reforestation
Despite these challenges, there is hope. By the turn of the millennium, previously deforested ranch land within the Sanctuary had transformed into a lush, biodiverse ecosystem. This success was achieved through hybrid reforestation, which involves planting both native and non-invasive introduced species.
Why Not Exclusively Native Plants?
A common question we encounter is: Why not focus solely on planting native species? The answer is multifaceted:
- Grass Suppression: Invasive grasses thrive in sunlight and prevent other plants from germinating. Their kryptonite is shade. Non-native, fast-growing trees can quickly establish a canopy, shading out these grasses and creating conditions favorable for native species to regenerate.
- Growth Rates: Native trees, such as koa and ʻōhiʻa lehua, often grow relatively slowly and do not form dense canopies, making it challenging to manage invasive grasses, compete against non-native invasive species, and restore habitats effectively.
- Availability: Historically, native plants were scarce. Even today, resources like the Hawaii Forestry Service primarily supply non-invasive introduced species, with limited availability of native trees.
- Disease Resistance & Pathogen Control: Biodiverse ecosystems can reduce pathogen spread. Diverse plant communities have been shown to support a more diverse and resilient soil microbiome, fostering natural fungal resistance and overall forest resilience.
Hybrid reforestation addresses these challenges by utilizing available non-invasive species to establish initial forest cover. This approach stabilizes the climate, supports the water cycle, and provides habitat, allowing native species more space and time to recover naturally.
Supporting Evidence: Case Studies from Hawaii
Several case studies illustrate the benefits of hybrid reforestation in Hawaii:
1. Hawaiian Legacy Reforestation Initiative (HLRI)
- Since 2014, HLRI has planted over 400,000 endemic trees across 1,200 acres along the Hamakua Coast of Hawaii Island.
- Their approach involves planting a mix of koa, ʻōhiʻa, and non-invasive species to create a balanced ecosystem.
- This project has successfully restored native habitats, enhanced biodiversity, and sequestered carbon.
2. Auwahi Dryland Forest Restoration Project
- Started in 1997 on the southwestern slopes of Haleakalā, Maui, this project is restoring one of Hawaii’s most endangered ecosystems: the dryland forest.
- By fencing off areas to exclude ungulates and planting native species, degraded pasture lands have been transformed into thriving forests.
- This initiative has revived rare and endangered plants while preventing further erosion and habitat loss.
3. Pālamanui Dry Forest Preserve
- Located in Kailua-Kona, Hawaii Island, this preserve is a collaboration between the University of Hawaiʻi and the Hawaii Department of Land and Natural Resources.
- The project aims to protect and restore lowland tropical dry forests by removing invasive species and planting a mix of native and non-invasive trees.
- The hybrid approach has helped reestablish native vegetation while providing educational opportunities for the community.
Ongoing Restoration Efforts
Once a stable hybrid forest system is established, ongoing efforts can focus on increasing native species diversity, especially as more native plants become available. Collecting seeds from local populations further supports this process, ensuring that reforestation efforts are ecologically appropriate and sustainable.
In conclusion, while the ideal scenario would involve exclusively native forests, practical considerations often necessitate a hybrid approach. By integrating non-invasive introduced species into reforestation efforts, we can accelerate ecosystem recovery, restore degraded landscapes, and support Hawaii’s native biodiversity.
One thing is certain: Having trees is always better than having no trees at all. We need forests to survive! Let’s find ways to help our forests thrive and preserve the unique biodiversity they contain in Hawaii and around the world.
With Aloha,
Andrew McWhirter
4th Generation Family Steward
