In the Garden
Rick Barboza
Pick plants to protect
native speciesOver the past year or so, I have been fortunate to share information about native plants with the people of Hawaii. I've received a lot of positive feedback, and I greatly appreciate those of you who actually take the time to read the articles.
I love answering your questions and providing you with whatever information that I can. I thought this first column of the new year would be a good time to catch up, so here are some answers to some frequently asked questions. I hope they will bring out the "native plant enthusiast" in everyone, so they can see why Hawaii's natural environment is so important.
Question: What is a native Hawaiian plant?
Answer: A native Hawaiian plant is one that got to Hawaii initially via a natural process. Specifically, this means arriving here without the help of man.
Usually a plant's seed or a fern's spore will arrive by what Hawaii naturalists like to call the three W's: wind (riding wind currents), wing (stuck in the feathers or ingested in the stomach of birds) or wave (floating on ocean currents).
Once a new plant (often called a pioneer species) begins to grow here, it is called an indigenous species, meaning it is now native to Hawaii but is also native to wherever it came from and possibly other places as well.
Over time, assuming that this new plant becomes naturalized, it can evolve to better suit its new home. Once this plant has differentiated significantly from its original ancestor(s), it is considered endemic to Hawaii. This means the particular plant species has become completely unique to Hawaii and can be found nowhere else.
Q: Why are native Hawaiian plants so important?
HUI KU MAOLI OLA
The likolehua, the opening leaf bud of the lehua plant, symbolizes new beginnings. The lehua is a native plant that would be a good addition to a local garden.
A: Hawaii has roughly 1,100 known native plant species. Of these, a staggering 90 percent are considered endemic! This is due in large part to two main factors:
>> The age of our island chain: The Hawaiian Islands are roughly 70 million years old -- enough time to allow for ample evolutionary changes.
>> Our severe isolation: Smack dab in the middle of the Pacific Ocean, the Hawaiian Islands are considered the most isolated land mass on Earth. Once a plant gets here, it's here to stay, meaning its gene pool will most likely be restricted to Hawaii, one island in the chain or even an individual valley within an island.
These two factors -- coupled with the fact that Hawaii was once void of many of the plant predators common to the rest of the world (most notably, large grazing mammals) -- have resulted in the extreme evolutionary diversity that has made our native Hawaiian plants so unique.
Q: Does "Hawaiian name" equal "native Hawaiian plant"?
A: Not necessarily. Countless species that bear Hawaiian (or Hawaiian-sounding) names are anything but Hawaiian. In fact, many are extremely harmful and do significant damage to our fragile native ecosystems upon introduction to the wild.
Here is a short list of some of the most common Hawaiian impostors: he'e (octopus tree), 'ohai ali'i, kiawe (mesquite), pakalana, koa haole (haolekoa), pikake, kuawa (guava), pua kenikeni, laua'e, pua melia (plumeria), liliko'i (passion fruit), tiare (Tahitian gardenia), maunaloa, ali'ipoe, waiwi 'ula'ula (strawberry guava) and la'amia.
Q: What about plants such as taro and ti leaf?
A: Some of Hawaii's most culturally significant plant species are not truly native! Brought to Hawaii in voyaging canoes by Polynesian settlers who depended on them for subsistence and survival, these important plants are classified as Polynesian introduced species.
Although not technically native plants, most have been growing on Hawaii's isolated shores for more than 1,000 years. Many have been cultivated here for so long they have become unique to Hawaii. Some of the most notable Polynesian introduced plants: 'awa (kava), mai'a (banana tree), 'awapuhi (shampoo ginger), milo, hau, niu (coconut tree), kalo (taro), noni (Indian mulberry tree), ki (ti leaf), 'olena (turmeric), ko (sugar cane), 'uala (sweet potato), kukui (candlenut tree), 'ulu (breadfruit tree).
Q: Why have most native plants become so rare?
A: Hawaii's native ecosystems have been under severe attack for more than 200 years, resulting in a major extinction crisis. Countless endemic plant species are gone forever, and hundreds more are quickly following the same path. Our state flower, the yellow hibiscus known as ma'o hau hele (hibiscus brackenridgei) is threatened with extinction.
The four major reasons for the demise of plant species:
>> Introduction of livestock: Cattle, horses, goats, pigs, sheep, etc., were introduced to the Hawaii in the late 1700s. Hawaii's native plants evolved here over millions of years in the absence of these large, grazing mammals, so most species lost their natural defense mechanisms. What awaited the first waves of livestock was nothing short of an all-you-can-eat native Hawaiian plant buffet! This directly resulted in the destruction of thousands upon thousands of acres of native habitat and the rapid extinction of countless native plant species.
>> Agriculture: Beginning in the mid- to late 1800s, thousands of acres of land on all the major islands were stripped of existing plant species and replanted with sugar cane and pineapple.
>> Urbanization and development: The decline of commercial agriculture over the past 60 years has paved the way for massive development projects. Many of these housing and commercial developments have stampeded back into valleys, up onto ridges and down onto beaches that managed to escape the brunt of previous attacks from livestock and agriculture.
>> Invasive alien species: Countless species of alien plants have already become naturalized in our islands, and many more are aggressively establishing themselves as we speak. These invasive plants outcompete natives for food, water, sunlight and space. Many have come to dominate vast expanses of our delicate island ecosystems. Some even produce toxic chemicals in their leaf litter and/or roots which prevent seeds of other species from germinating.
In sum, these influences have taken a staggering toll. Our lowland dry forests have taken perhaps the worst blow, as they represent the region most directly affected by livestock, agricultural and developmental degradation. Sadly, only about 5 to 10 percent of our native lowland dry forests remain. This is especially devastating considering this ecotype once held the largest diversity of native plant species in Hawaii.
Q: What can I do to help?
A: Two simple ways: buy native Hawaiian plants and don't buy invasive alien species.
Most local gardens, landscapes and even many reforestation projects are still dominated by non-native plant species. But the tide is slowly changing. A recent law now allows the propagation and sale of federally endangered native Hawaiian plant species by certified growers. This is a step in the right direction for the perpetuation of these highly threatened plants. The overall appreciation for native plants is also steadily increasing, as is commercial demand.
As for avoiding invasive alien species, although far from complete, here is a quick list of some of the worst and most aggressive alien species: African tulip trees, lantana, banyan trees, melastomes, guava trees, octopus trees, ironwood trees, passion fruit vines, kahili ginger, strawberry guava trees, fiddlewood trees, Christmas berry.
By supporting native Hawaiian plants, not only will you be beautifying your yard or garden, you will also be helping support and perpetuate this integral part of Hawaii's natural and cultural history. The time is now and the movement is on!
Rick Barboza co-owns Hui Ku Maoli Ola, a native Hawaiian plant nursery, with Matt Schirman. Contact him at 259-6580 or e-mail rickbarboza@hawaii.rr.com.
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