So many people have stated here that if we make a lake, that micro-invertebrates will colonize it by themselves. In native prairie reconstruction, this most definately does NOT occur. As a matter of fact, saving insect species and micro-invertebrates is one of the most difficult problems facing prairie reconstructionists.

With this being the case, why is it so easy for these species to colonize water and so difficult for them to colonize land?

Norm - Some types of invertebrates are much better at colonizing new waters than others. Some of the early colonization is due to the proximity of a nearby water body. Many invertebrates to name a few, clams and snails, are sometimes very slow at colonizing new waters. Some invertebrates get introduced but do not establish themselves either short or long term for one reason or another. Sometimes in new water bodies the early colonists have low diversity compared to old established waters. Inflowing stream water is responsible for higher diversities in a lot of new waters. Isolated relatively new water often has high abundances but low diversity.

I am not sure why terrestrial colonization is slower, if it truly is. Is there proof of this? Maybe I misread your last question. Are you talking about, why is it more diffcicult for aquatic species to colonize land habitats vs aquatic habitats? or colonization in general?

Bill,

Stupid question; How do zooplankton species populate an isolated body of water? It sounds like all you have to do is fertilize to get the phytoplankton going, and then you have zooplankton shortly after. I know algae species can travel as spores, but how does the zooplankton get there? I have ideas but I'd like your take on this.

Bill, how do invertebrates such as zooplankton colonize isolated bodies of water?

From what you said, I gather that only generalists that are highly mobile colonize our lakes. Is that true? Does it matter?

In the long term, highly complex ecosystems produce much more biomass than do simple systems. The exception to this is if we continually add resources to simple systems. Does this matter?

As far as I know (limited specialization here) I am not sure how many of the colonization techniques I suggest have been proven with experimental research. I may have to literature search this a little more.

Proven- Many of the crustacean plankters esp the cladocerans produce ephippium (resting eggs) and rotifers produce mictic haploid resting eggs. Ephippia and resting eggs can withstand freezing, drying, anoxia and passing unharmed through digestive tracts of fish. Because of the resistant ephippial eggs Cladocera are easily transported overland to new habitats. It has been speculated that newly exposed soil contains relic ephippia and when inundated with water the ephippia hatch. Ephippia are also small enough to be lifted from dried up wet areas, carried in dust and wind storms and deposited on land and water sites. Wind rows of ephippia and resting eggs can pheasably be easily entangled in/on or eaten by birds and transported and then deposited. It is much easier to enision birds moving and transporting sporulated microparticles than birds transproting live fish. Many microalgae and pollen are transported this way which has been proven scientifically. Many of the zooplankton in a new water body are represented by a community of very low diveristy. Aging increases the diversity.

Generalists are usually responsible for early colonization. Aging processes, animal and human activities and evolution usually add to the diversity. Initially generalists and maybe an occassional specialists depending of conditions and evolution causes specialists that adapt to niche situations. Some niches are not filled and diversity is relatively low in some isolated waters.

I am not sure about what you are asking or saying about impact of resources on complex and simple ecosystems. Do you have a specific example in mind. It all depends in many situations. As I understand it higher diversity is always better and the ecosystem becomes more stable as divesity increases.

I will see what else I can find on zooplankton dispersal.

In my bussiness (lab monkey, bug picker, or technician) anything you can see with a dissecting scope is a macro-invertebrate, including rotifers and cladocerans.

Some scientists believe that ephippia can remain viable for a decade, and since cladocerans reproduce asexualy, only one needs to get into a lake.

Most other inverebrates, aka all of the insects, have adult stages that fly and can lay eggs in new lakes.

I think the generalists are usually the most common inhabitants in the older nearby water bodies of newly built or flooded waters. (Flooding introduces many new species.) Thus it stands to reason that generalists are most likely to be the first ones that get introduced. New waters quickly get populated by a few taxa and over time the numbers increase by various methods. From the begining, it is survival of the fittest based on who can best survive in the prevailing conditions.

Hey "bug picker technician" (I won't call you a lab monkey), micro-invertebrates are different than macro-invertebrates. I'm sure you realize this, others may not. Your lab may have a slightly different definition and study purpose than the typical Rapid Bioassessment Water Quality Protocols (methods) that are popular today. But, macroinvertebrates are usually defined as invertebrates that are easily or readily visible with the unaided eye; things like snails, shrimp, worms and insect larvae. Microinvertebrates are typically defined as those small enough to need magnification to pick them from a sample or net, things like the smaller crustacean zooplankton and other types smaller, down to the one celled animals. As you probably know by now, there are those that are transitional between the two groups and technicially some overlap occurs between the groups with things like smaller Naididae worms, nematodes, hydra types, tardigrades, and numerous early instars of insect larvae, etc.

Norm,

The original question was "why is water is so easy and prairie is so difficult?"

In ponds and lakes it is easy to establish the bottom of the food chain nutrients. You get a lot of help as per the other replys.

On land, the bottom of the food chain nutrients are harder to re-establish. I once poured a container of liquid nitrogen out on the grass behind the lab and it sterilized a three foot diameter area that took several years to regrow. Carbon must be broke down before it can be used and the microbes and much smaller animals that do it require a balanced diet and a balance environment that is normally established over a long long period. Prairies are a special problem as they lack certain nutrients to support higher level life forms such as trees. In my area, the prairies contain too much salt.

Bottom line, to re-establish any killed off land area, bring in healthy earth from healthy near by areas and spread over the killed off areas.