What is diversity and why is it important? Why do environmentalists carry on so about it?
A single species' population has many individuals that carry different genetic variations which may not be expressed by the population at large, but stored in the genetic code. Individuals that have the expressed code fitting the demands of new conditions can allow the group to survive difficult environmental stress.
Trophic hierarchies within niches of organisms have different specialists with redundant attributes. And if conditions, such as weather alterations, illnesses, loss of food sources, toxic conditions, cause extinction of some specialist species within a habitat, the environment can, to a degree, continue. However, the redundancies of the specialists, within the trophic layers, are vital to the plasticity and resiliency of the environment. Losses of specialists can cause trophic collapse reducing function and production of the environment. Generalist species can take the place, to some degree, the position of the specialist but may not fulfill all the attributes and functions to be the surrogate support the trophic layer and collapse may only be a bit later rather than sooner.
So, genetic variation allows populations to weather ecologic alterations. Redundancies of specialists within trophic layers allow for whole habitats to weather ecologic alterations. Wolves, spotted owls, polar bears are in one tropic layer but have few redundancies within their habitats. Their numbers are few so their genetic library is limited. With climate change how resilient is the world's environment to human consumption of species and habitats?
Monday, May 30, 2005
What is diversity and why is it important? Why do environmentalists carry on so about it?
Saturday, May 28, 2005
Sunday, May 15, 2005
People's Pets, Pests and Parasites...
Mountains that ring Los Angeles burn so frequently that the trees do not have time to re-grow. Fire ecology means that the plants and animals have adapted to periodic conflagrations. However, even though the mountains are not developed, the cities and the ever-increasing human environment affect them, and so fire comes more frequently and has more devastating effects. (http://www.werc.usgs.gov/news/1999-09-16b.html ) What this means is that this undeveloped land is in effect, 'developed' and the plants and animals that live there are more inclined to be tolerant of disturbance and dependant on humans.
What kinds of plants and animals live with or near people and benefit from their proximity?
Mostly animals domesticated or habituated to take food and find protection from living near or with humans... and they bring all of their pests and parasites, too.
Zoonosis disease is like a bonus point for civilization and animal husbandry. Zoonosis is when viral and bacterial disease and all other parasitic diseases, which are not species specific but can jump easily from one animal to another. Pets, dependent on people for food shelter and reproduction... have transmitted Tuberculosis, Plague, Rabies, Ringworm, and Lyme disease. Domesticated food animals like pigs, live in crowded conditions near farmers and cities. Diseases like influenza viral strains, of say, the avian plus the human specific influenza viruses, (which have receptors and similar biochemistry within pigs) which can either kill one or the other, now, within the vessel of the pigs' systems, can do both. Even pet dogs can be infected and can carry potential diseases that may be passed onto their owners and trainers, which may have originated from some other animals across the globe. (http://www.recombinomics.com/News/05140503/H3N8_Florida_Widespread.html)
The pests of humanity like rats and mosquitoes have other interesting stories. Rats and mice that carry the Hantavirus come in contact with humans because of seasonal conditions. (http://coloherp.org/cb-news/archive/vet-med/hantavir.php) When rains increase the food supply for rodents in the Southwest, their populations expand, but drought brings them into cities where people sprinkle and store food. The rodents invade the peoples' homes and transfer the virus through their excrement either fresh or dry. Although, experts have said that Hantavirus is rare it has found a home in large cities like New York. (http://www.health.state.ny.us/nysdoh/communicable_diseases/en/hanta.htm)
People spray, scrape, dig, uproot, and pour concrete over the land. Near the confines of their cities, plant and animal life is different. Plants and animals must quickly take advantage of momentary peaks of water use or rain, crops or garbage, pets of prey or illness. What plants or animals existed where the people live, are gone or mostly and those at the perimeter of the cities are mostly gone, too.
Weeds - plants that take advantage of the disturbance caused by people - grow quickly, fruit and die. The insects at the interface of the human environment are mostly the groups that either eat what humans grow or throw out, or eat the detritus and carrion.
So, in the spring of 2005, affected by several years of drought and fire, the rains came. Forests protect the mountainside and the lower watersheds by holding back waters and rocks and mud. The forests of Los Angeles were mostly gone, burned, or so near completely burned, they looked like a landscape of black skeletons.
The Cement Rivers carried the majority of the water to the ocean. The Bolsa Chica may not survive another season of rain like this, especially if fires come in summer and burn what is left of the San Gabriel's.
Thursday, May 12, 2005
The Mugu marsh has many micro-habitats that support a variety of wetland life. Mugu marsh is also a Naval Base which scrutinizes all who enter. Only those with official business on the Base can step foot within the gates. This is a good thing for plants and animals that have been extirpated from their other wetlands, beaches, and salt pannes ...they have a small safe place for a while.....
People, no matter how thoughtful, impact these sensitive areas. Scientists who study the environment must tread lightly. SUV's and ORV's never ever - I repeat - never tread lightly. Tiger beetles live in sand in mud and eat the flies, ants, bees and other beetles that cross their holes in the soil. As adults, disturbed areas in the marsh, along beaches, sand bars, along rivers and streams, salt flats, run until they are torn up for buildings and roads. So many spots for tiger beetles, and the animals we support near water have been lost to the industry of people.
Wetlands were the trash bins of cities.
Now, the wide open areas are for off-roading.
Insects that live near or develop in water can carry disease, but most do not. The insecticides that kill the mosquiotes and black flies kill other insects as well. And,.... DDT still hides as a poison in the mud.
People's buildings, even miles away, impact the beaches and marshes because water flows downhill. People who spray lawn grower and pesticides might as well pour those chemicals directly on us! Everything that may be poured, excreted, spilled, leaked, regurgitated or purposely put on the streets ends here. Beaches and marshes are so full of the chemicals of people, the water in the mud can cause animals to be sick, be less fecund and die early deaths.
The marshland used to protect the oceans by filtering the water that flowed through the upper watershed, but there are more people pouring and spilling then there are natural filters to filter. Even if the people filter the water (supernatant) that flows from their streets from the urban sludge, people must find ways of disposing of the 'matter' safely. Increasingly, there are fewer places that can be used as dump sites that are at a distance from urban/suburbia. The Army Corps of Engineers have a special division that supervises the Department of Defense's dump sites (Formally Used Defense Sites - FUDS) but are concerned that urban development is growing faster then they can assess and maybe clean up. The sprawl will be at the edge of many areas set aside and made inaccessible because of radioactivity, explosives, and other toxic materials used for war.
This is a picture of Salicornia surrounded by diatom mats. Diatoms are silicon 'shelled' algae that will grow together on the soil when tides of the ocean fill the marsh and stands for a time. Tiger beetles can run across the slick of water to catch Ephidirdae feeding on the dyeing vegetation. The diatoms grow greenish, then turn yellow then black. Pink fungus grows with the diatoms in the mud. It may look radioactive, but it isn't.
This snake has a lovely set of rattles. Not all adult snakes keep all of their rattles as they grow and so counting the 'buttons' is not a good way of aging the reptile.
There are rats and voles and mice for snakes to eat. Rats, voles, mice eat beetles! I like snakes.
Tuesday, May 10, 2005
Birds with long beaks dig deep in the mud. They come in groups. When the sun rises, they fly. In the dark of the morning, cormorants bicker with each other for a steady spot on the high tension lines near by. Who said they could perch with their short legs and webbed feet?
When the tide rises the mud gurgles and burps.
Friday, May 06, 2005
Thursday, May 05, 2005
This river flow is at the mid section of the mountain high above Pasadena, California.... At one time tiger beetles ran the river's mud banks. Are there any left?
Disticulus is found along the California coastline where there are marshes which dry out now and then.... and, Disticulus grows in patches in Death Valley where there used to be ocean tides. Tiger beetles live there in the muds and sands of ancient ocean beaches.
This winter, the hundred year storms created lakes of water not seen for so long. Springs in the desert had pupfish mating, marsh plants - Disticulus and Salicornia sp. (pickleweed - edible for humans)- flourished, and tiger beetles ran.
In these holes larvae wait for small animals to walk by unaware of tiger beetle awaiting jaws. Adult tiger beetles dig holes under the plants and rocks for their night time refuge and rest. Solitary bees dig holes like these next to tiger beetles. Sometimes the bees become food for tigers. Tigers are maticulous about their appearance (they clean themselves all the time and when they are 'nervous') and their holes in the mud are dug in perfect cirlces - they are perfect!
Wednesday, May 04, 2005
Within hours of shedding its outer skin, a transparent pupae emerges. Pigmentation begins the second day starting with the eyes, then the mandibles, then the legs and the elytra. Pupae, many times, lie under the soil in this configuration - on their backs.
Tuesday, May 03, 2005
This winter in 2005, the rains came and washed large areas of land away. There used to be many areas in Southern California where the tiger beetles ran, so if a terrible storm washed many of the colonies away there would be others to generate populations again. However, much of Southern California has cement and few open places where tigers can run.
You can tell my species from the more common C.oregona by the hairs (setae) on my head (and not just around my eyes) and from the tiny teeth near the end of my elytra near my butt(wing covers)! There is another colony of C. s.frosti, but they are in Riverside County California. Perhaps there are more. But chances are that they aren't. We need space, and insects, and good water. Heavy animals and such kill us when we are young in our holes in the mud.
The sun made me fast. Faster then the other insects around me. Every morning I would dig myself out of the dirt and stand in the sun. If it got too hot, I would run to the shade. I could feel the temperature rise and I would stand taller and taller away from the hot ground. If I kept my temperature up to 32 degrees C, I could out run the fastest fly, wasp, and spider. But, as night fell, I had to find a spot to hide from the night and morning birds. When I was cold, below 25 degrees C, I was food for all.