Search Results for: phenology

It’s a Girl!

Alcatraz garden volunteers have faithfully been monitoring selected native plants on the island since February as part of the California Phenology Project.

The native plants have been scrutinized at least twice a week for growth of leaves, flower buds, open flowers, pollen release, fruits, ripe fruits and seed/fruit drop. For each of these observations, a quantitative estimate is given. Among the native plants that have been closely watched is Coyote brush, Baccharis pilularis.

Plants are fascinating to grow for whatever reasons the gardener finds rewarding – the promise of food, the enjoyment of the flowers, providing habitat, or just for the fun of it. For the phenology watchers, learning each plant secrets has its own rewards that only come after months of observing. The four coyote brush on the island have finally revealed the secret of their sex to us! Alcatraz has two males and two female plants.

Everyone knows that (most) plants have flowers, but many people may not realize that the flowers have male and female parts, and in some cases, that the male and female flowers are on separate plants.

The coyote brush is one of the plants that have the male and female flowers on separate plants. This is known as being dioecious, meaning to have two houses in Greek. The opposite is to have the reproductive parts on one plant, or in one house, being monoecious. What is the difference between the male and female flowers? The male flowers contain the pollen, held on the anthers, while the female flowers open to reveal the stigma and

Female flower. Photo courtesy of Blue Planet Biomes.

Female flower. Photo courtesy of Blue Planet Biomes.

style. Bees or other insects will take pollen from the male and will brush the pollen on the female flowers in their effort to gather nectar. The female flowers are oblong with a narrow opening at the top. Inside, the pollen will land on the stigma and ‘travel’ down the style to the reach the ovary where the seeds will ripen. Once the seeds are ripe, the seeds will be dispersed by the wind carrying the fluffy tufts away. On Alcatraz, there is a lot of wind, so the seeds are dispersed quickly. 

The first male plant began to flower on July 17 and finished flowering September 25.The females flowered next, while the second male plant began to flower September 25 and is still flowering. It is interesting to note that the

Male flower_Photo courtesy of Blue Planet Biomes.

Male flower_Photo courtesy of Blue Planet Biomes.

male plants are growing on different sides of the island, and have different flowering times. Maybe after a few years of observations, we can draw more conclusions about why this is. By flowering at different times, the cottony female ‘seeds’ are released and float on the wind to be carried away to reach a distant male. This helps to increase the genetic variation amongst a plant population – a cool evolution trick. 

Can you think of other plants that have male and female flowers on separate plants?

Here are a few – holly, gingko, kiwi vines and mulberries. Knowing which plants have separate male and female flowers will help gardeners plan their garden. For instance, if you wish for bright red holly berries, you must plant a female bush, but you will also need a male to fertilize it. Or, you should also take into consideration garden maintenance – a messy female gingko tree will drop the fruit or even the female coyote brush may be too messy for some people’s liking. 

At any rate, plants can continue to amaze, just take the time to notice them.

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Science of the Seasons

What is phenology? Phenology is the study of seasonal or periodic biological events such as plant leaf-out and flowering, insect emergence, and animal migration. Put simply, phenology is the science of the seasonsIn order to assess the effects of climate change on California’s extraordinary biodiversity and natural resources, the California Phenology Project was established in 2010 as a 3 year pilot project. The pilot project is focusing on 7 parks, including the Golden Gate National Recreation Area.

 

Corny walking her phenology trail with her clipboard. Photo by Shelagh Fritz

Corny walking her phenology trail with her clipboard. Photo by Shelagh Fritz

Corny Foster, a garden volunteer, also volunteers with stewardship of Crissy Field, an area just east of the Golden Gate Bridge. A few plants in her area are being monitored as part of the California Phenology Project, and so she thought ‘why aren’t we doing this on Alcatraz’? Alcatraz has 2 of the 5 native plants that are being monitored in the Golden Gate National Recreation Area – California poppy, Eschscholzia californica and coyote bush, Baccharis pilularis. Project wide, over 60 plant species are being monitored. The species were selected based on their ability to address key scientific questions and to inform natural resource management, as well as their ability to engage the public (charisma and easy identification are important!).

Our plants are being monitored for breaking leaf buds, young leaves, flowers, open flowers, pollen release, fruits, ripe fruit and recent fruit drop. Our phenology trail takes about 30 minutes to complete and we are hoping to build a volunteer group to do the twice weekly monitoring. Eventually, we hope to invite school groups out to observe the plants and to build on their school lessons, and to show them that looking closely at plants is FUN!

The checklist of what to look for. Photo by Shelagh Fritz

The checklist of what to look for with simple ‘yes’ or ‘no’ answers. Photo by Shelagh Fritz

The island’s environment provides a unique opportunity to study the plants. We will be able to compare our flowering times with plants on the mainland and find out just how much being surrounded by water affects our plants. Plus, Alcatraz does not have any gophers, so our California poppies are never tampered with. The selected plants to be monitored on Alcatraz do not receive irrigation.

Simple to observe and record, phenology offers a way for “citizen scientists” to

A California poppy staked out on the trail. Photo by Shelagh Fritz

A California poppy staked out on the trail. Photo by Shelagh Fritz

learn about the rhythms and natural processes of their local environment while observing directly the important links between the living world and the climate system. If you would like to volunteer to monitor our plants, send an email to info@alcatrazgardens.org.

 

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