Plants

Plants

5

Rain in the Mojave Desert

A desert tortoise prepares to snack on a desert mallow.

When most people think of the desert, they don’t think much about rain. Well, on August 22, the Mojave Desert experienced record-breaking rainfall, with some areas receiving well over 2.5 inches (6 centimeters) of rain within a 24-hour period, which caused major damage to the area. Most damage was due to washed-out roads and to low-lying property. But altogether, the desert had a much-needed drink for such a hot and dry summer.

Desert plantains have sprouted after record rainfall in the Mojave.

The aftermath of so much rain caused an explosion of plant life to appear throughout the desert. Some plants had not been seen in certain areas for many years. Plants such as the desert plantain Plantago ovate, desert mallow Spaerlcea ambigua, and golden bush from the genus Ericameria, just to name a few, started growing all over the desert. These plants are some of the desert tortoises’ favorite foods, which will help them have a full stomach before they go down for hibernation in the winter.

Daniel Essary is a research associate at the San Diego Zoo’s Desert Tortoise Conservation Center. Read his previous post, Rabbits, Rodents, and Tortoises.

0

The Right Tools

Two boys admire aguaje fruit, an important resource in the Peruvian Amazon.

Sometimes all you need is the right tools.

In August 2010, I spent three weeks trudging through swamps in the Peruvian Amazon to assess the aguaje palm population on the lands of an indigenous group known as the Maijuna. Aguaje is an avocado-sized fruit with smooth scales covering a thin layer of bright orange flesh. It is high in Vitamin A and very popular in the large Amazon city of Iquitos. As a result, rural communities from all over the region, including the Maijuna, harvest aguaje to supply the city’s demand. But the tree’s height (up to 90 feet or 27 meters!) means that the fruit is often harvested by cutting the palms down.

Aguaje fruit awaits buyers in the market place. It is spread out so shoppers can assess the quality.

The extreme heights are also difficult to measure, and attempting to do so in the boot-suctioning mud of the swamps wasn’t always easy for us in the field. But the animals don’t mind: a plethora of wildlife, including monkeys, parrots, tapirs, and peccaries, are known to frequent the aguaje palm swamps to feast on the fruits.

While I was in the swamps, Michael Gilmore of George Mason University conducted interviews with Maijuna villagers. The objective of our combined work was to better understand the management needs of aguaje. A few years ago, the Maijuna decided to reclaim sovereignty over their natural resources by keeping outsiders, especially loggers, from coming onto their lands and better managing their own use of the land’s resources. This included finding a better way to harvest aguaje without killing the palms, and some of the community members learned to use climbing harnesses to reach fruit at the top.

A group of community members shows off their new climbing harnesses. Every household with a member attending the workshops received a harness.

But not everyone could climb. What Michael found out in the interviews was that, for many families, no one knew how to climb, so some continued to harvest the old-fashioned way, with an ax, even though they knew of the consequences. Even people who knew how to climb would sometimes use axes. What struck me, however, was how many families said they just stopped harvesting fruit because they didn’t know how to climb and wanted to conserve the palm trees. That is awesome! It shows a commitment to sustainable management and that the people place a high value on the future of the resource. But it also means those families are missing out on a potential source of income. When the average family income is just over $500 a year, the few dollars made from selling some sacks of aguaje can make a big difference. This partially explains why some people continue to cut.

Key to workshop success was ample time for attendees to practice climbing. Practice allows people to become comfortable at the extreme heights needed to reach the fruit.

After our assessment in 2010, it was clear that the Maijuna needed more training. And more equipment. The 37 households in the 2 villages were sharing a handful of harnesses, and they weren’t always available when needed. So in 2011, we held climbing workshops and invited everyone from the villages. We shared our study results, but most people were already aware of the negative impacts of cutting palms. We focused on hopeful things: there are a lot of seedlings and saplings growing in the damaged swamps that will provide fruit in the future. And we gave the people a lot of time with the expert climbers. Everyone got to practice and get comfortable with the climbing harnesses. We also wanted every household to have the right tools, so every household received a harness.

We didn’t expect the workshops to solve everything. The stands of aguaje palm need to recover from the years of destructive harvesting. But things did improve—a lot. In 2012, we went back to evaluate. Even though many more families harvested and the community harvested 50 percent more sacks of fruit, the number of cut palms went down. And now, instead of over half of the palms harvested being cut down, only about 14 percent were. To me the encouraging sign is how many more families were harvesting fruit, now that they knew how to climb. Their willingness to restrain from harvesting before, even though they would have liked to, shows commitment to resource management. All they needed all along were the knowledge and the tools for better management practices.

That’s San Diego Zoo Global’s role in this project: trying to figure out the best tools for the community’s goals and help them obtain those tools. Next with aguaje, we’ll be working with the community to figure out the best ways to improve the stock of aguaje palms on their lands. We want to make sure there’s enough aguaje for both wildlife and people.

Christa Horn is a research coordinator in the Applied Plant Ecology Division of the San Diego Zoo Institute for Conservation Research. Read her previous post, A Grand Experiment for Palm Trees.

1

Maui Youth Lend a Hand

We thank the Hawaii Youth Conservation Corps for their efforts!

Sometimes we can all use a helping hand. Do you remember a blog about the battle we fight against the invasive plant known as gorse? (See Gorse Crisis: Making Way for Native Plants.) Well, the Maui Bird Conservation Center (MBCC) benefited from the generous efforts of eight hard workers from the Hawaii Youth Conservation Corps (HYCC). They battled for two long days against a particularly stubborn patch of over-grown gorse and then placed native plants in the cleared space.

As background, the nonprofit organization Kupu, which is dedicated to providing opportunities for the youth of Hawaii, operates the HYCC. Kupu offers Hawaii’s young adults the chance to gain job training and life skills such as leadership, communication, responsibility, and teamwork, while encouraging service within the community. During their summer program, high school students spend six weeks as Americorps interns, assisting in the protection of the environment while learning about natural resource management through projects such as trail maintenance, native plant restoration, and coastal restoration, plus many other experiences.

Young koa and uki uki plants have a chance to thrive now at MBCC.

A crew visited MBCC after working at various sites on Maui and Kahoolawe for projects with The Nature Conservancy and the Maui Forest Bird Recovery Project. Yet they still had the energy to tackle our gorse problem! Led by Christine Molina, the team leader who works as a teacher during the school year, the team of Carl, Issac, Kamana, King, Kyla, Pololou, and Stephanie split into two groups. As one group toiled away with saws and pruners to remove the gorse, the other team broke through the rooted soil with shovels to dig holes, which they filled from several large trays of native plants, donated by Anna Palomino, a local native Hawaiian plant expert who generously donates extra plants to MBCC. Their combined efforts made short work of an area that would have taken our MBCC team a month to clear and plant, with all of our other duties pulling at our attention.

Although the restoration area does not look especially spectacular now, with time and nurturing by the MBCC team, we hope the native plants will flourish and be a source of pride for the future, thanks to the wonderful and diligent work of the Hawaii Youth Conservation Corps.

Joshua Kramer is a research coordinator at the Maui Bird Conservation Center, operated by San Diego Zoo Global. Read his previous post, Hawaii: Native Birds and Plants.

7

Cactus Wrens Rise from the Ashes

Coastal cactus wrens build their nests in large prickly pear cactus. When cacti are killed by land clearing or wildfires, wrens have nowhere to nest.

After the 2007 Witch Creek Fire, which burned through the San Diego Zoo Safari Park and surrounding San Pasqual Valley, the outlook seemed grim for local populations of coastal cactus wrens. With populations already rapidly declining throughout Southern California, we all wondered if the fire, which heavily damaged critical nesting areas, was going to be one of the last chapters in an all-too-familiar story of species loss. A survey for coastal cactus wrens within the Safari Park Biodiversity Preserve shortly after the fire turned up only 10 pairs, further suggesting the population here was in a precarious position.

Even as the land smoldered, we began developing habitat restoration plans to help speed up recovery of native habitat. We focused on two critical coastal cactus wren needs: prickly pear cacti, which the birds need to nest, and native shrubs such as elderberry, buckwheat, and California sagebrush. Our goal was to enhance 45 acres (18 hectares) of habitat to support the recovery of wren populations and ensure the long-term survival of the species here in the San Pasqual Valley.

We have propagated thousands of native prickly pear cacti to support habitat restoration for cactus wrens.

Efforts began in 2008 and involved propagating and planting thousands of cacti and native shrubs across difficult, rugged terrain. Sometimes, the last four years seem like a blur of hard work, hot temperatures, sweat, blood (cactus spines hurt!), and more work. The effort, led by Sara Motheral and Colleen Wisinski, has been nothing short of amazing. We are nearing our goal! This year, we will complete the habitat enhancement of the 45 acres. Even more exciting is the fact that wren populations are rebounding—it is hard not to see or hear wrens calling while walking in the Safari Park Preserve.

Colleen Wisinski monitors a cactus wren nest, checking for eggs, at the Safari Park’s Biodiversity Preserve.

Even as we approach one milestone in the project, we are already expanding our efforts beyond the Preserve and have begun developing habitat restoration plans throughout San Pasqual Valley to connect isolated populations of wrens and create new habitat patches. It is only a matter of time before the next wildfire happens, and the long-term survival of the wrens depends on having high-quality habitat within the Preserve and throughout San Pasqual Valley.

To this end, we are already propagating cacti to enhance an additional 50 acres (20 hectares) of habitat throughout San Pasqual Valley and utilizing advanced technology such as Geographic Information Systems, spatial analysis, and computer modeling and simulations to help us determine high-priority locations for habitat restoration efforts to maximize the probability of success. No rest for the weary!

Bryan Endress is the director of Applied Plant Ecology for the San Diego Zoo Institute for Conservation Research.

0

Gorse Crisis: Making Way for Native Plants

Amanda and Amy remove some invasive gorse.

It goes without saying that wild bird populations are dependent upon good quality, natural habitat for foraging, nesting, and escaping from predators, to survive. The native forest birds of Hawaii face a multitude of threats, and the loss and degradation of habitat is one of the primary reasons for the decline of these unique species. Invasive plants and animals are taking over and destroying their forest home. For example, introduced pigs and deer browse on the plants and churn up the forest floor in search of food, killing native seedlings and providing an opening for faster-growing, invasive plants to gain a foothold in native environments. In many cases, in order to restore native plants, we must first remove the nonnative ones.

Gorse in bloom. Note the nasty thorns!

Gorse is one such invasive plant common in parts of Maui as well as the Big Island. The dense, prickly shrub, introduced to Hawaii in the 1800s, originated in western Europe, where it is still valued as a living fence for livestock. In addition to its aggressive tendencies, gorse grows much more quickly than most of Hawaii’s indigenous species and easily out-competes them for space and sunlight. Today, gorse is considered to be a serious weed, and all attempts to eradicate it have failed. The International Union for Conservation of Nature recognizes gorse as one of the top 100 worst invasive species in the world; so far, the best-recognized method for combating gorse is to plant faster-growing plants that are able to shade out sun-loving gorse.

At the Maui Bird Conservation Center, we have our own gorse crisis. Fellow intern Amy Kuhar and I are tackling our gorse invasion head on. Because the gorse defends itself with innumerable thorny spikes, we have started by taking down different sections of the weed in phases. We start by trimming back branches with loppers, then we use hand saws to sever each plant at the base. When possible, we also dig out the roots. The process is very time consuming, and we have worked many hours on the project. “Painstaking” would be the best adjective to describe the effort, because the gorse fights back, and after an afternoon of gorse eradication, we are left with innumerable itchy, tiny thorns embedded under the skin of our hands, arms, and legs!

A mamane sapling planted at the MBCC.

In addition to rescuing resident koa, ‘ohia, and mamane trees choked by gorse around the facility, we also began the process of replacing the invasive vegetation with native plants such as `a`ali`i and more mamane. In one area alone, we have planted more than two dozen new trees and are excited to see them growing over the newly cleared area! But the battle does not end there. One of gorse’s greatest weapons is its massive production of seeds, which can lay dormant in the soil for many years. As the older gorse is cleared, the seeds rapidly germinate, and within a few weeks there is a bed of new gorse seedlings. To stay on top of these, we must spray with herbicide to prevent another new invasion, allowing the native plants to flourish.

Hopefully, future interns will continue to clear gorse to make way for more native planting, all of which will someday create habitat for our wild, feathered friends such as the `amakihi. We hope the native plants will also eventually provide a source of perching, nesting material, berries, and seedpods for the birds in our care.

Amanda Maugans is an intern at the San Diego Zoo Maui Bird Conservation Center.

0

The Answer, My Friend

A capuchin monkey perches on a palm frond as it sways in the wind.

Pop Quiz: What’s invisible, odorless, an unlimited natural resource, and sometimes taken for granted…even cursed upon? Here is a clue: We are now using this renewable resource to produce about 4 percent of our electricity needs in the U.S., and that number is rapidly growing. If you guessed the wind, you’re correct! The almighty wind, a constant and reliable key to our planet’s ecosystem, is so common and present we tend to not even think about it. Now that we are starting to realize its potential, it might be a good idea to look closer at how plants have learned to live with and use it and perhaps learn a thing or two.

Using the wind to disperse seeds is one of the ingenious tactics plants have developed as a survival skill. Lightweight, propeller and parachute-like material attached to seeds represent the most notable and clever use of the wind. Still, there are many other ways. Your idea of the desert may be one of tumbleweeds rolling across the barren, desolate landscape; because deserts tend to be windy, tumbleweed plants have figured out that their best chance of continuing on is to have their seeds dispersed as far and wide as they can. They do this by growing into the shape of a shrubby ball and dying shortly after they set seed. The consistent wind then blows the tumbleweed across the desert, rolling and bouncing, causing its seeds to spread along the way. Using this method, tumbleweeds have figured out the best solution to their problem. Then again, they have had countless years to perfect it!

Another area to look at, and probably more applicable to biomimicry, is how plants protect themselves from the damaging power of wind. Many trees in windy areas have leaves that are thin and narrow, thus reducing the surface area and potential force of strong gales. Palm trees, on the other hand, have developed creative ways to live in harmony with the wind, the most common being in the tissue structure of the petioles (the stems). Here, the petioles are constructed into a crisscrossing mesh of fibrous material, creating a flexible and super-strong tether for the palm fronds and the trunk. What you get is a system that can move and adjust effortlessly as the wind dictates. A possible bio-inspired design could have similarly designed materials for the posts of giant billboards, awnings, or other large stand-alone structures. This could lead to less destruction and death caused by flying debris during hurricanes.

Bonus question time: Where are you most likely to find answers, solutions, and inspiration for many of our current, everyday challenges? Hint: It’s all around us. If you guessed the natural world, you are right, and you, too, are bioinspired!

Seth Menser is a senior horticulturist at the San Diego Zoo. Read his previous post, Seeds Make the World Go Round.

8

Tecate Cypress: Risky Reproduction

Lauren and Sandra Mardonovich sow Tecate cypress seeds in long pots that provide spacious room for roots.

The Tecate cypress Hesperocyparis forbsiiis a tree found only in Southern California and northern Baja California, Mexico. It has a limited range and is fire dependent, which means the cypress needs fire to reproduce. The cones of this species are serotinous, which means the seeds are released by an ecological trigger (in this case, fire) instead of being released once they reach maturity. When the cones are exposed to heat, the resin that keeps them sealed is melted, the cone opens, and the seed is released. Without fire, the Tecate cypress keeps its seed bank within persistent cones in the tree canopy. When a fire burns a mature stand of Tecate cypress, new seedlings pop up in its place. If this second generation is burned before it reaches maturity, it could wipe out the entire population. There are only four stable populations remaining in California, three of which are in San Diego County. It is because of its limited range and risky reproduction technique that this tree is such a sensitive species.

Tecate cypress cones collected from Otay Mountain await processing.

The Applied Plant Ecology Division at the San Diego Zoo Institute for Conservation Research has partnered with the Nature Conservancy, the Bureau of Land Management, and the California Department of Fish and Game to preserve this unique species. The goal of the project is to provide a safe guard against high-frequency fires wiping out the population.

To do this, we collected enough seed from a mature population to have a portion for safe keeping in the Native Plant Seed Bank at the Safari Park and a portion that could be germinated and planted as a nursery stand. Cones were collected from Otay Mountain and processed at the State of California’s Lewis A. Morgan Reforestation Center. The processed cones resulted in thousands of seeds, and of those, a fraction was planted. From the planted seeds, we are hoping to get 400 to 500 seedlings.

Here's a close-up view of the seeds before being covered with soil.

Once the seedlings have grown to a suitable size, they will be planted at the Rancho Jamul Ecological Reserve. The planted cypress trees will be monitored over the next six months. These trees will be used as a sort of “plantation” where more seeds can be collected as needed in case the other stands burn before reaching sexual maturity.

Lauren Anderson is an intern at the San Diego Zoo Institute for Conservation Research through the Bureau of Land Management’s Seeds of Success Program. Read her previous post, The Desert: Blooms and Hail.

2

The Desert: Blooms and Hail

Grape-soda lupine

San Diego County is the most botanically diverse area in the U.S., with nearly 2,000 species, many of which are endemic (unique to a defined geographic area, so many are found only in San Diego County). There are not many places where you can experience the ocean, the snow, and the desert within a couple hours. The desert transition habitat is found down the east side of the Peninsular Ranges, and this is the site of our recent seed collection trip. The weather forecast looked ominous, but we were optimistic. To get to our site, we had to drive up and over the Cuyamaca Mountains and out into the lower elevations beyond.

Apricot mallow

When we finally reached our site, we saw a mix of cacti, shrubs, and huge granite boulders. It was freezing cold and very windy. At certain points the wind became so strong it was difficult to open the truck doors to get out and identify plants. Despite the rough conditions, it was a beautiful place to explore. We saw desert apricot Prunus fremontii, golden gooseberry Ribes quercetorum, and grape-soda lupine Lupinus excubitus in bloom.

As the day wore on, the weather only got worse. When we tried to collect a sample of apricot mallow Sphaeralcea ambigua, the rain turned to hail, and we decided to admit defeat for the day.

McCain Valley overlook

On the drive back up and over the Cuyamacas, the hail turned to snow! It was so much fun to watch everything turn white throughout the course of our drive. We followed a snowplow most of the way down the mountain; I never would have imagined experiencing something like that in Southern California! As we dropped in elevation, the snow slowly changed back into rain and everything turned green again. It was odd to realize that we had only been a half an hour away from the ocean.

San Diego is truly a remarkable place, and I couldn’t ask for a better area to study plant diversity.

Lauren Anderson is an intern at the San Diego Zoo Institute for Conservation Research through the Bureau of Land Management’s Seeds of Success Program. Read her previous post, Wake Up, Seeds! Germination Testing.

7

Analyzing Bamboo and other Foods

Bai Yun analyzes her nutritious bamboo.

What, if any, analysis is conducted at the San Diego Zoo to check the nutritional value of the different kinds of bamboos given to the pandas? The Nutritional Services departments at the Zoo and San Diego Zoo Safari Park routinely sample our animals’ foods for nutrient analysis. We do not have a complete nutrient laboratory onsite, but we send feed and forage samples to multiple laboratories around the country to get complete nutrient profiles as needed. What our nutrition laboratory can do is prepare samples for analysis through oven- or freeze-drying techniques and grind the samples to 1 millimeter to ensure a representative sample.

It has been a number of years since bamboo has been analyzed for the giant pandas. Joyce Nickley, a former keeper at the San Diego Zoo Safari Park, completed her masters of science research by looking at the nutrient content of bamboo, with the results published in her thesis as well as in a chapter in Giant Pandas: Biology, Veterinary Medicine, and Management (2006, edited by D.E. Wildt, et al.). Additional browse plant analysis has been completed on multiple primate browse species, four of the many species of eucalyptus grown for koalas, four species of acacia browse, and pennisetum used for the elephants. Every load of hay (Bermuda grass, Sudan grass, and alfalfa) is sampled for nutrient analysis, and our custom feeds, commercial feeds, and prey items (insects, fish, rodents) are routinely analyzed.

Our typical analysis includes moisture, protein, fiber (neutral detergent fiber, acid detergent fiber), and minerals (calcium, phosphorus, magnesium, potassium, sodium, iron, zinc, copper, manganese, molybdenum, sulfur chloride, and cobalt). In addition to these basic analyses, we often have lignin, sugar, starch, and fat analyzed. Due to the increased cost, we only analyze vitamins (A, D, E, C, and B vitamins), fatty acids, amino acids, selenium, and iodine for specific projects or clinical cases.

Routine nutrient analysis of the feeds we use at the Zoo and Park has allowed us to build a database of feed nutrient profiles that help us formulate diets for all of our animals, including our popular pandas, to keep them healthy and satisfied.

Michael Schlegel is the director of nutritional services for San Diego Zoo Global.

1

Elephant Odyssey through Horticulturist Eyes

Golden barrel cactus

Zoo InternQuest is a seven-week career exploration program for San Diego County high school juniors and seniors. Students have the unique opportunity to meet professionals working for the San Diego Zoo, Safari Park, and Institute for Conservation Research, learn about their jobs, and then blog about their experience online. Follow their adventures here!

Today at the San Diego Zoo we met with horticulture expert Mike Letzring, who took us on a tour through Elephant Odyssey. Mr. Letzring, who is the collections manager, pointed out the diverse collection of plant life found in Elephant Odyssey. He shared his perspective on plants, which goes much deeper than looking at a plant’s surface. He sees a rare and unique live organism that has a super capability to survive with little to no water!

Mr. Letzring shared with us how he and his team of landscapers are not only in charge of the plants outside of the exhibits but also for the plants that go inside. In this rattlesnake exhibit at Elephant Odyssey, the Horticulture Department chose plants that are native to San Diego because they are relatively drought tolerant like the plants rattlesnakes are used to being around in their natural home, the desert.

In Elephant Odyssey, we stopped at a very interesting tree. This tree is sometimes referred to as an “upside-down tree” because its branches look like a root system. Mr. Letzring, explained to us that this tree is very rare and indigenous to Madagascar. Make sure the next time you are in Elephant Odyssey, you take a moment to look at this amazing tree!

This brilliant orange and yellow flower is indigenous to San Diego. Mr. Letzring tells us that this unique-looking flower is called “the monkey flower” because its petals resemble the shape of a monkey’s face. Can you see it?

Along this particular walkway in Elephant Odyssey, do you notice a theme among the plants? When designing this area, Mr. Letzring and his team wanted to go with a theme that included plants with spines (thorns). The plants were received from a generous donor, a local San Diegan!

One of the plants we stop to look at was the African Erythrina latissima. This plant’s biggest threat is the gall wasp. Mr. Letzring showed us how the gall wasp penetrates the plant, which ultimately destroys it.

One of the last plants we came across on our tour was the golden barrel cactus. To our surprise, it’s actually possible to pull out the flower of the cactus to reveal a good source of moisture inside it. We learned that this cactus is very valuable to animals that come across it in the hot desert.

 

At the end of the tour, the interns had the rare opportunity to sample these delicious exotic fruits! What a treat to sample dragonfruit! It is clear that Mr. Letzring and his team work hard to spice up the Zoo with a variety of plants to not only diversify the landscape but for us to learn about the amazing world of horticulture.

 

Kayla, Photo Team
Week Two, Winter Session 2012