Feeds:
Posts
Comments

Posts Tagged ‘Plants’

A study was published earlier this month in the journal Frontiers in Ecology and the Environment on the effects that invasive species have on other species around the globe. The study is by Tim M. Blackburn, Celine Bellard, and Anthony Ricciardi, and it can be found here.

The main thrust of the paper is that invasive species of plants and animals have been found to have a significant impact on the extinction of other plants and animals all around the world. Specifically, 25% of the plant species that have gone extinct in recent years have been the result, at least in part, of invasive species. Additionally, 33% of the animal species that have gone extinct in recent years have been the result, at least in part, of invasive species.

These numbers are pretty compelling components to the story of just how damaging invasive species can be. It is part of the reason I find working on invasive species control in California to be rewarding.

I am currently working on the control of Arundo (which is a large invasive reed), water primrose (an invasive aquatic plant), Phragmites (which is another invasive reed that is a bit smaller than Arundo), and Nutria (which is a 20 pound semi-aquatic rodent). Each of these species pose unique threats to the native species of California and to many other aspects of the ecosystem as well.

Hopefully, protocols can be developed to stop invasive species before they contribute even more extinctions!

Read Full Post »

This is a link to a blog post I wrote for the UC Davis-USDA Delta Region Areawide Aquatic Weed Project website. The Sacramento-San Joaquin Delta Conservancy (the agency I work for) gets funding from the USDA to control Arundo infestations in the Delta.

Arundo (which I have written about previously here) is a highly invasive plant that causes bank destabilization, increased fire hazard, increased water use, and excludes native plants and animals. The Delta Conservancy has been coordinating with a the Sonoma Ecology Center and the USDA to apply treatments of herbicides and/or insects that are specific Arundo parasites to eliminate Arundo from as much of the Delta as possible. This work began last summer/fall at the Brannan Island State Recreation Area, as site that is owned by California State Parks and which has a lot of Arundo.

Read Full Post »

Delta Conservancy Logo 3The Sacramento-San Joaquin Delta Conservancy (the state agency where I work), which is based in West Sacramento, is currently looking to hire a Senior Environmental Scientist (Specialist)! The position is heavily involved with invasive plant work, particularly focusing on Giant Reed (Arundo donax) in the Delta. It will also be quite involved with managing Proposition 1 grants for habitat restoration, water quality improvement, and sustainable agriculture projects.

If you are interested, or know someone who might be, please check out the official job posting here. It is a great agency to work for!

Read Full Post »

When I am out walking just about anywhere in central California, one of the plants that I see growing all around me is Mallow. From back yards in Berkeley to sidewalk edges in Sacramento to fields in the Sierra foothills, mallow, with its deep green leaves and small flowers, is all around us. But, these common weeds are often overlooked, and I think this is a real shame because they are such a delicious food!

The name mallow refers to plants of the family Malvaceae, which contains close to 2,300 species worldwide. They are found throughout the temperate and subtropical regions of Europe, Asia and Africa, and have also been introduced to North America where they are doing quite well, indeed. This family contains numerous important crops plants such as Cotton, Hibiscus, and Okra. Other species of mallow are planted as decorative garden flowers or considered agricultural pests. They grow pretty much everywhere including lawns, along edges of fields and roads, and often in our own gardens.

As a food plant, mallow has one of the longest recorded histories on record. The ancient Greek poet, Horace (65 BCE to 8 BCE), was said to enjoy a simple diet of “olives, endives, and mallows.” Greens can be eaten raw in salads or cooked as either a saute green or in soups. The seeds have many medicinal properties as well, and the flowers and buds are also edible. One aspect of mallow that I find makes it particularly satisfying as an edible is that it grows so abundantly. Large plants can be found that will supply several meals of easy-to-gather leaves, and will re-seed themselves to allow for future foraging.

Additionally, mallow plants are very easy to identify. They have round leaves that range from 2 to 5 inches across, and that grow on alternating sides of the stems. The stems and undersides of the leaves are covered with small hairs. These hairs can be somewhat bristly, especially on larger leaves, so only the smaller leaves should be used in salads. The hairs soften when exposed to heat and so do not add any unpleasant textures to a cooked dish; therefore larger leaves are fine to eat as long as you are planning on cooking them. Plants can grow in several forms from low-lying herbaceous plants only a few inches off the ground, to large bushes that can be 6 feet tall, or more. Their small, five-petal flowers (0.25 to 2 inches across) range from white to pink to purple.

Two interesting side notes on the members of the mallow family. One is that they display a characteristic called protandry which means that young plants are all males and they change to being female later in life. The other is that it is thought that the color mauve got its name from the French word for the mallow plant.

So watch for mallow when you are out and about, and enjoy!

Read Full Post »

The life cycle of plants is quite different from the life cycle of animals. Plants go through a cycle called alternation of generations which means that there are two multicellular stages. One is diploid, called the sporophyte, and one is haploid, called the gametophyte. In contrast, our animal life cycle has only one multicellular stage, the adult that we are all in as we read/write this.

These two multicellular stages mean that there are a lot of other facets in the plant life cycle that may be unfamiliar to those of us with animal life cycles. The one that I am going to focus on here is the difference between spores and gametes. In dipoid organisms, like us, we have no spores. Our only single cell stage are our gametes. But plants have both spores and gametes and this can lead to some confusion because there are some similarities between the two. Spores and gametes are singles celled, and they are both haploid. But these are pretty much the only similarities you will find.

Fundamentally, spores and gametes are very different. One difference is in the type of reproduction that each are involved in. Spores are used in asexual reproduction, while gametes are used in sexual reproduction. Another difference is in what each needs to develop into the next stage in the life cycle. A spore has the ability to grow into the adult gametophyte all by itself. It does not need to interact with any other cell to do this, all it needs is to find favorable growing conditions. A gamete has to fuse with another gamete before it can form a zygote that then can grow into the adult sporophyte. A third difference is in the life span of these cells. Spores have a very tough outer layer that allows them to remain dormant, but viable, for extremely long periods of time (sometimes decades or even longer) in order to persist through periods of poor conditions until better growing conditions arise. Gametes are much more delicate and generally only remain viable for a matter of days, and so must find another gamete quickly. A fourth difference, related to the how long each cell lasts, is dispersal ability. Especially in more basally derived plant lineages, spores can disperse very, very long distances. They are small and light, and so can be carried by the wind for hundreds, or even thousands, of miles. Gametes, on the other hand can only disperse very short distances. The egg, the larger gamete, is generally retained and so does not disperse at all while the sperm, the small gamete, will swim to find an egg, but will generally only swim a few inches. Yet another difference between spores and gametes is the process by which they are created. Spores are created through meiosis. The structure that produces a spore is diploid and so must go through a process of chromosome reduction in order to create the haploid spores. Gametes are produced by mitosis. The structure that produces a gamete is already haploid and so does not need to change the number of chromosomes it has in order to produce haploid gametes.

So, hopefully this post explains how different spores and gametes are. I wanted to highlight this information because I see it as a common source of error.

Read Full Post »

I recently saw, and smelled, a blooming Corpse Flower (Amorphophallus sp.) for the first time, and it was amazing!

The genus Amorphophallus is comprised of about 200 species that generally inhabit secondary forests of in the tropics and subtropics of Africa and the Pacific Islands.  The plants grow from a stem that is underground, called a tuber or corm, and from this stem they grow one leaf.  But, this is no ordinary leaf.  It can grow vertically up to 2 or 3 meters tall.  The petiole can get to be around 15 cm across, and is cool and smooth to the touch.  At the top it then splits into three horizontal blades that each have many leaflets.  It is a very beautiful leaf with the petiole a mottled pattern of light and dark green, and the leaflets a bright fresh green.  The overall impression is that it is a tree, and not a single leaf.  Each leaf lasts only one growing season before it dies back, so these plant are deciduous.  The plant will grow several leaves, over several growing seasons, to accumulate nutrients in the corm.

Once it has enough stored energy, which generally takes 3 to 6 years, it will bloom.  The single blossom can be huge!  It is a spectacular deep, dark red and black flower and it smells like something between rotten meat and spoiled fish.  The smell can be oppressive.  The one that I got to see was in the UC Davis Plant Conservatory, and the back third of the greenhouse was filled with smell.  Flies are attracted to this smell and are the insect pollinator for the flower.  The flies are so convinced that they have found a wonderful food source that they often go so far as to lay their eggs in the flower.  Flowers of the species in this genus must be pollinated the same day they open.  Once the female parts of the flower have been pollinated, the male parts (which had been concealed) open and begin to release pollen.

If anyone is on the Davis area, I would highly recommend paying the Plant Conservatory a visit and checking out the Corpse Flower while it is still blooming.  If you do not make it to see this plant’s flower, there is another Corpse Flower plant that is  likely to bloom next year and that one is even bigger!

Read Full Post »

Over the past couple of weeks spring has been becoming ever more evident in central California.  For one, large flocks of American Robins have been showing up.  These are likely groups of Turdus migratorius propinquus, large and pale subspecies, that are migrating from their wintering grounds in central Mexico, through central California on their way to their breeding grounds which could be anywhere from northern California to British Columbia or Montana.  I saw another sign that spring is in the air Tuesday as I was walking across campus.  Near one of the large lecture halls, I heard and saw a male Cooper’s Hawk kekking from the top of a large tree.  This was the first Cooper’s Hawk breeding behavior that I have seen this year, and two day later I saw and heard him again in almost the same spot.  Hopefully he will attract a female and set up a nesting territory here.  It would be a lot of fun to watch.  Another breeding behavior that I have just seen starting is that the male House Finches have stated mate-guarding the females.  I watched one particular male as he followed a female around as she foraged, and repeatedly chased off other males that approached too close to the female.  A final sign from the birds that the seasons are changing was a male Nuttall’s Woodpecker checking out cavities as potential nesting sites.  He was moving through a couple of dead trees in West Sacramento, and stopping at any hole he could find.  he would take a few moments at each to look at the external hole, and then stick his head in to take a look at the interior.  He rejected all the contenders save for one, which he poked his head into, and apparently liked.  He climbed all the way in, and over the next 10 minutes or so that I stayed to watch, he did not come out.  Apparently that was a good spot!  To add to these avian signs of spring is one of my favorite plant signs.  The fruit trees that fill the orchards and line many of the streets in the West Sacramento and Davis areas are all in bloom!  I do love the beauty of trees covered in small white or pink blossoms.

Read Full Post »

Older Posts »