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Category — Horticulture

Great Gardens at the Zoo

Guest blogger: Zoo Academy Student, Elaina Allen

Here at the Cincinnati Zoo we have a lot of fascinating animals to look at from leaf-cutting ants to Asian elephants. However there is more to the Cincinnati Zoo; the Zoo is also known for its amazing plant displays. One plant display in particular that I will be discussing is the amazing Dinosaur Garden located outside of the front entrance of Reptile House on the right side near Monkey Island.

The Dinosaur Garden was designed in the 1970s through 1980s around the time the Zoo also became a botanical garden. A botanical garden is an establishment where plants are grown for display to the public and often for educational study. The purpose of the Dinosaur Garden in particular is to convey knowledge to the visitor about the prehistoric plants that lived around the same time as the dinosaurs.

Dinosaur Garden (Photo: Elaina Allen)

Dinosaur Garden (Photo: Elaina Allen)

One thing interesting you can find inside the garden is the Araucarioxylon arizonicum or the petrified log. When a plant is fossilized it is considered petrified. The Araucarioxylon arizonicum is an extinct species of conifer that is known for its massive tree trunks.

Petrified log, Araucarioxylon arizonicum  (Photo: Elaina Allen)

Petrified log, Araucarioxylon arizonicum (Photo: Elaina Allen)

My favorite species to look at while in the area is the China Fir because this tree has pointy needles, which is an adaptation to defend itself against large animals such as dinosaurs.

China fir (Photo: Lazaregagnidze)

China fir (Photo: Lazaregagnidze)

Observing the Dinosaur Garden you will notice that some of the plants come and go, depending on the season. The Horticulture staff makes sure to maintain and keep up with the changes in the weather, and also the requirements or needs of the plants in the garden. Horticulture is the art of garden cultivation and management. The staff in the Horticulture department maintains any appropriate plant species throughout the Zoo.

So next time you decide to visit the Zoo, check out the Dinosaur Garden and the many other plant displays. You won’t regret it!

January 23, 2015   21 Comments

Saving Animals in the Wild: The Zoo’s Top Field Conservation Efforts of 2014

Happy New Year! As we look back on 2014, let’s reflect on some of the Zoo’s significant contributions to wildlife conservation in the field this past year:

Nasha and cubs snoozing on the  savannah

Nasha and cubs snoozing on the savannah

Helping Lions Thrive in Kenya’s South Rift Valley

Since 2011, the Zoo has partnered with the African Conservation Centre and the South Rift Association of Land Owners in Kenya on the Rebuilding the Pride program. This community-based conservation program combines Maasai tradition and modern technology to restore a healthy lion population while reducing the loss of livestock to lions in Kenya’s South Rift Valley. Once down to a low of about 10 known lions in the area, the population has grown to more than 65 lions in 2014. This past April, a lioness named Nasha gave birth to another litter, this one containing three cubs. That the population is growing in the South Rift Valley at a time when lion populations are severely declining across the continent overall is significant and a testament to program’s community-based approach.

Sumatran rhinos at the Sumatran Rhino Sanctuary in Indonesia

Sumatran rhinos at the Sumatran Rhino Sanctuary in Indonesia

A Giant Step Forward for Sumatran Rhinos in the Wild

The Zoo has been committed to saving the Sumatran rhino for 25 years. Despite the devastating blow of the loss of our female rhino, Suci, back in March, the Zoo continues to work to conserve and protect the species. In 2014, a Debt-for-Nature deal was struck between the United States and Indonesia. In return for lowering the debt Indonesia owes to the United States, it will commit nearly $12 million towards the conservation and protection of critically endangered species, including the Sumatran rhino, and their habitats over the next seven years. The debt swap was made possible by a contribution of about $11.2 million from the U.S. government under the Tropical Forest Conservation Act (first introduced by Ohio Senator Rob Portman in 1998) and $560,000 from other organizations funneled through Conservation International. The Zoo was proud to help secure this funding by pledging a major gift.

Pollinating American chestnut trees with cryopreserved pollen

Pollinating American chestnut trees with cryopreserved pollen

Saving American Chestnut Trees with Cryopreserved Pollen

The magnificent American chestnut tree once ranged over the entire Eastern United States, but was almost entirely obliterated by blight by the mid-twentieth century. Over the years, breeders have been working to develop a resistant tree, and one of their key tools is pollen. American chestnut pollen rapidly declines in viability so maintaining important lines of pollen from year to year is difficult. In 1993, pollen was cryopreserved (frozen) in liquid nitrogen at the Zoo’s Center for Conservation and Research of Endangered Wildlife (CREW). Last spring, some of that pollen was removed and used to successfully pollinate trees at the American Chestnut Foundation’s farm in Virginia. Paternity testing will be done at CREW this winter, but the indications are very good that cryopreservation can indeed maintain pollen viability for at least 20 years—a fact that should provide a new tool to those working to save this majestic American tree.

Kea Conservation Trust staff conducting kea research (Photo: Nigel Adams)

Kea Conservation Trust staff conducting kea research (Photo: Nigel Adams)

Committing to Kea Conservation in New Zealand

Over the past few years, the Zoo has supported the Kea Conservation Trust’s (KCT) efforts to protect and study New Zealand’s mountain parrot, the kea, in the wild. In 2014, the Zoo stepped up its efforts with a commitment to support the Kea-Community Conflict Response Plan, a multi-year proactive community-focused conflict response and resolution program. Funds from the Zoo support a key personnel position, the Community Volunteers Coordinator, who can respond to conflict situations that arise. Funds will also enable KCT staff to enhance their conflict resolution skills by participating in a Human-Wildlife Conflict Collaboration Workshop. Additionally, Zoo aviculturists will join the KCT team for kea nest monitoring and field work over the next couple of years.

Dr. Alan Rabinowitz, CEO of Panthera, a global wild cat conservation organization, installs a camera trap in Bhutan. (Photo: Steve Winter)

Dr. Alan Rabinowitz, CEO of Panthera, a global wild cat conservation organization, installs a camera trap in Bhutan. (Photo: Steve Winter)

Pledging Support for Panthera’s Tigers Forever Initiative

The Zoo is committed to ensuring the survival of endangered tigers of which there are fewer than 3,200 remaining in the wild. In 2014, we have pledged multi-year support of the tiger conservation efforts of Panthera, the leading international wild cat conservation organization with a mission to ensure the future of wild cats through scientific leadership and global conservation action. To ensure the tiger’s survival, Panthera works across Asia with numerous partners to end the poaching of tigers for the illegal wildlife trade, prevent tiger deaths due to conflict with humans and livestock, and protect tiger prey species and habitat. Through their program, Tigers Forever, Panthera works to protect and secure key tiger populations and ensure connectivity between sites so that tigers can live long into the future.

Wetlands in restoration at EcOhio Farm

Wetlands in restoration at EcOhio Farm

Restoring Native Wetlands and Wildlife in Mason, Ohio

In 1995, a 529-acre farm in Mason, Ohio, now called the EcOhio Farm, was willed to the Zoo with the guideline that it could never be developed unless it is to further the mission of the Zoo. Over the past few years, the Zoo has worked to restore 30 of the farm’s acres to its original state of a wet sedge meadow, providing refuge for a diversity of native wildlife. Since restoration began in 2012, drainage tiles have been removed and more than 200 native plant species and thousands of trees have been planted on the site. The wetland is returning to its natural state very quickly. Already, it has attracted more than 135 native bird species, including bald eagles, bobolinks and killdeer, which would never have been there when it was a cornfield. Though not currently open to the public, walking trails and a small education center may be implemented in the future to provide opportunities to explore the wetland.

Cincinnati Zoo gorillas, Asha and  her infant, Mondika, named for the field conservation project (Photo: Michelle Curley)

Cincinnati Zoo gorillas, Asha and her infant, Mondika, named for the field conservation project (Photo: Michelle Curley)

Strengthening our Support for Gorillas in the Republic of Congo

Over the past 20 years, the Zoo has partnered with the Nouabale Ndoki Project (NNP) in the Republic of Congo, which includes the Mbeli Bai Study, the longest running study of the critically endangered western lowland gorilla. The Zoo also supports work in an area called Mondika where gorillas are habituated for up close research and ecotourism. Habituation is a process through which the wild gorillas become accustomed to and tolerate the presence of people that enables researchers and tourists to observe them up close. The Zoo recently helped facilitate the habituation of a second group of gorillas, and entered into an agreement in 2014 to support the habituation of a third group over the next three years. Special thanks goes to Gorilla Glue, our official gorilla conservation sponsor!

All of these projects and more couldn’t happen without your support of the Zoo. Here’s to you and the Zoo making more great strides for wildlife conservation in 2015!

January 7, 2015   No Comments

Lessons Learned from a Year of Aquaponics

Part 3: Lessons We Learned From Our First Year With Aquaponics

By Scott Beuerlein, Horticulturist

Sustainability Intern Mary Sticklen teaches guests about aquaponics during the 1:30pm Keeper Chat.

Sustainability Intern Mary Sticklen teaches guests about aquaponics during the 1:30pm Keeper Chat.

Fish

After extensive conversations with the genius engineers who helped me start the system, and a couple of really smart and friendly experts at Jones Fish Hatchery, I chose to go with bluegill and catfish (which, by the way, were donated by Jones Fish Hatchery). There was wild enthusiasm around the Zoo for tilapia, but I had worries using a tropical fish in a system that would not only be a start up with the oscillating fluctuations in water quality that goes with that, but would also experience significant daily changes in water temperature during winter. Our system is heated—kept at a minimum temperature in winter of around 60F, but on sunny days the greenhouse can zoom up to 80F, which is the point where it vents. Water temperature would follow, and I was not sure tilapia could handle that. So I chose catfish and bluegill, despite everybody’s wishes, and endured weeks of abuse and ridicule until another dude made an even worse decision.

The fact is the bluegill and catfish did well, and I still feel it was a good decision for that time. Early on, we did experience a wild ride of water quality before the bacteria stabilized and before the plants grew on enough to achieve adequate balance with the fish. More importantly, our water hardness is astronomical and that’s not something we have much control over. Bluegill and catfish are unfazed.  Even more impressive, due to a learning curve (read: “series of blunders”) on the water return system (described later), the system virtually drained itself of water on several occasions. Needless to say, the only choice upon finding nearly empty tanks was to fill with tap water.  Of course we added this water at the far end of the system, allowing it to pass through both our gravel and raft tanks which brought it closer to temperature and possibly helped to release some of the chlorine, but this was far from ideal. Nevertheless, we never lost a fish due to this, which is a real testament to the toughness of these species of fish.

In recent weeks, however, we have had a couple of issues with the catfish, in part because they are a scale-less fish.  After consulting our Curator of Aquaculture and Reptiles, Jeff Mitchell, my worries about tilapia have been allayed, and we are considering a gradual replacement of the catfish with them.

We have lost fish. Early on, we had a few jumpers. Since this occurred almost entirely when water quality had not yet stabilized, there’s been some speculation that maybe this was the cause. Maybe it was because I was singing too many Nick Cave songs while working in the greenhouse. Who knows?  Things have gotten much better, and we seldom lose any fish.

As for harvesting fish, we haven’t done that, although the decision looms. Yes, I have in fact named all the fish and we’ve had some good times together. This probably wasn’t very smart. Chef never did bond with any of them, and he sees the fish only as the delicious fillets they might one day become. We’ll see what happens. A year ago we started with 6” or smaller fingerlings. The catfish now appear to be 3-5 pounders.  The bluegills are still fairly small and not yet what a fisherman would call a “keeper.”

Plants

Our best successes have been tomatoes, basil, bok choi, beets, chard, and chives, with some basil, chard, and tomato plants living for nearly a year. We had tomatoes producing in all but the darkest few weeks of a very cold and gray winter. Disappointments have been peppers and lettuces. The difference between success and failure seems to be the ability to grow fast and strong. Aggressive growers seem to skirt past that vulnerable seedling stage where aphids, snails, and damping off take them before their time. In just the summer months last season, we harvested over 30 pounds of basil.

Freshly harvested basil, ready for the cafe kitchens!

Freshly harvested basil, ready for the cafe kitchens!

Germination is almost instant in the wet, warm environment, but there’s a slow, lagging period until the seedlings finally reach a decent size. Once there, plants grow very vigorously, and respond to repeated harvests with very strong bursts of re-growth.  We’ve been trying to boost plants through the seedling stage with foliar fertilization, using fish emulsion and seaweed extract.

It is interesting that in the Fall, when daylight hours noticeably decreased, most of the plants responded by a marked decrease in growth, and no amount of fertilizing or other means seems to make any difference. It is just the plants natural response to diminishing daylight. It appears temperature is not a factor, because as the day length increased in early Spring, which wasn’t any warmer, the plants responded by putting on strong new growth.

Pests and Diseases

Overall, we’ve experienced remarkably few issues with plant or fish health in regards to pests or diseases. Our only two issues are snails and aphids. I don’t know how snails showed up, but they appear to be here to stay. There’s really no control, except to periodically lift the foam rafts and hose the little devils off into the gravel. This seems to keep their numbers low enough that the plants can grow past their predation on roots. The problem seems much less in the gravel and hydroton beds than in the raft beds.

Aphids are interesting. Their numbers ballooned as we went into the Winter months, and it was a challenge to keep them controlled with organic treatments of Spinosad and insecticidal soap. Aphids alone, I believe, prevented us from growing lettuce. At one point this Spring, all on their own, Lady Beetles (and their voracious larvae) showed up and had a noticeable effect on aphid numbers.  But, just as they mysteriously arrived, they mysteriously disappeared, but so did the aphids. Maybe it was the heat?

My philosophy with the aquaponics greenhouse is that if a crop is difficult, we’ll replace it with one that isn’t. We don’t have the time to make pest control a lifestyle. Becoming an expert on treatments isn’t on my bucket list, and we certainly aren’t going to introduce chemicals into an ecosystem whose whole success hinges on the fine balance of fish, bacteria, and plants. Nope, that’s a high wire act that doesn’t need morel variables.

Fertilizers

As mentioned before, foliar sprays of fish emulsion and seaweed extract (iron added) provide a wonderful occasional boost, especially to young or heavily producing plants. For some reason, iron is commonly low in aquaponic systems, as are calcium and magnesium. Because of this, once in a blue moon I add a dollop of seaweed extract (with iron) and a product called CalMag to the water. Call me crazy, but I can almost witness plants greening up and growing after application.

Cleaning

We don’t clean as often as you would think. This is as intentional as it is convenient. Aquaponics depend on healthy, functioning bacteria. Aggressive cleaning is detrimental to bacteria. So, we’re rather lackadaisical about scheduling heavy cleaning, especially of the bio-reactors, and we’re not very thorough about it when we finally get around to it. I learned this lesson from installing and maintaining garden ponds, and I learned it well. Give bacteria their space, and they’ll play nice.

Water Quality

Our water is hard, and will stay hard. Fact of life for city dwellers in the Midwest. The pH creeps down constantly, and I need to keep an eye on that. Otherwise, the system is remarkably stable. An interesting point about pH. You’ll remember that our system is split into two sides. The left has one tank filled with expensive clay balls called Hydroton, which overflows into a foam raft tank. The right has one tank filled with practically free round limestone gravel. It also spills into a foam raft tank. The pH on the Hydroton side was always threatening to fall below safe levels, requiring me to add things to try to bring it back up. But the gravel side remained remarkably stable. If you think about it, this makes perfect sense, because what’s better than lime to moderate acidity? We have half a ton of limestone gravel filtering every ounce of water as often as it passes through the system. One day it finally occurred to me, put a layer of limestone gravel on the floor of the Hydroton’s side raft bed, and see what happens. I did, and it has worked. The pH remains a little low, but not so low that I have to worry about it as much as I did.

Grow bed filled with clay balls called Hydroton.

Grow bed filled with clay balls called Hydroton.

When we began, I obsessed over water quality, testing constantly. Gradually, came to rely on the system and lost precious little sleep. More recently, we had a few problems with the catfish and Jeff Mitchell, our Curator of Aquaculture and Reptile, thought these were attributable to some water quality issues. We backed off on our feeding regimen some, which has lowered nitrate and nitrite levels, and we’ve been more aggressive about changing out water. Our problems have abated. Moral of the story: don’t get too complacent on water quality. You should lose a little sleep over it from time to time.

Turface and Rockwool

Rockwool is a heat expanded rock product that looks and feels very much like fiberglass insulation. It’s not cheap and I really don’t like the stuff. I have to use it on the raft tanks, because it prevents the plants from falling through the holes and into the water. Initially, I was told to use it on the gravel and hydroton beds too, which I dutifully did. But soon I began to wonder if I could just plant seed in those beds directly. I tried, and it mostly didn’t work. Much of the seed fell down through the crevices into the water. But I knew from starting rare plants from seed at home that Turface is a very useful product in media mixes. It’s a calcined clay product that looks like kitty litter. It is often used on baseball infields to dry up puddles or raise low spots. It has an astronomical amount of surface area, holds a lot of water, has an enormously high cation exchange (ability to hold nutrients), and I knew a layer of it on top of the gravel and hydroton would keep the seeds where they could germinate. It worked just as I suspected, and I haven’t looked back since. No expensive, gross rockwool in the gravel and hydroton beds, seeds are sewn direct.

Basil planted in Rockwool, ready to be placed in the floating rafts.

Basil planted in Rockwool, ready to be placed in the floating rafts.

Take Home Message

How sustainable is our system, and how sustainable is it for the average guy to do at home? These were questions we wanted to answer when we started the system. For us?  We started with a nice but fairly expensive greenhouse with a heating system, which means heavy costs up front and not incidental operating costs. Harvests exceed operational expenses, I’m sure of this, but how many years of operation will it take to recoup the initial capital costs? That’s a question for the genius engineers, I’m pleased to say, but certainly it would take time, and also the continued commitment of someone who is fairly passionate about the system. If our system were larger, enabling greater harvests, I believe that the relative harvest to costs ratio would wind up in the favor of aquaponics. But, again, over time. Less time, but still time. This is one reason why this system is so intriguing for urban agriculture.

Interestingly, I think for the homeowner on a budget who puts minimal capital into the system in the early stages (subbing a poly tunnel for a glass greenhouse, for instance), the prospects of economically sustainable success are improved. For one, the system can be opened in the summer to allow naturally occurring insect populations to limit pests, but also because you wouldn’t be heating the system in the winter. Yes, this brings production to a crawl for a few months, and you would also have to face the issue of getting the plant/bacteria/fish/water quality balance steadied every Spring, but you would have saved a ton of start up costs. There is still much to learn and improvements to make, which is to be expected from something so new.

Please come visit our greenhouse, which is located near the Base Camp Cafe. Weekdays during the summer months, we have a keeper encounter there every afternoon at 1:30PM. You’re also welcome to schedule a tour with us by appointment. Email Fia at gogreen@cincinnatizoo.org or myself, at scott.beuerlein@cincinnatizoo.org.

July 24, 2014   No Comments