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Mz: "From what I have read, swamps tend to fill in over time and turn into solid land -- unless there are alligators." Swamps abound in lands with no alligator

Mz: "From what I have read, swamps tend to fill in over time and turn into solid land -- unless there are alligators." Swamps abound in lands with no alligators whatsoever. In places where there are alligators, they can serve as an indicator species or keystone species for ecological studies. Certainly they alter their environment and create niches for other species, but they aren't necessary for swamps and they don't create swamps. Removing all the alligators from a swamp would not get rid of the swamp. Putting a bunch of alligators into an area will not result in a swamp being created in that area.

Mz 10y ago
Certainly they alter their environment Yes, that is what I meant. They alter their environment. I didn't intend to suggest that if you stick alligators in a non-swampy area, they create swamps by their very presence. Removing alligators from certain swamps would, in fact, significantly impact the swamp and make it much more likely to revert to solid land over time. Here are a few things my son looked up for me just this morning because we were discussing the topic: https://en.wikipedia.org/wiki/Alligator https://en.wikipedia.org/wiki/Alligator In 'Habitat' we have: "When [Alligators] construct alligator holes in the wetlands, they increase plant diversity and provide habitat for other animals during droughts." "Further west, in Louisiana, heavy grazing by coypu and muskrat are causing severe damage to coastal wetlands. Large alligators feed extensively on coypu, and provide a vital ecological service by reducing coypu numbers." https://en.wikipedia.org/wiki/American_alligator https://en.wikipedia.org/wiki/American_alligator At the very top of the page we have "They play an important role as ecosystem engineers in wetland ecosystems through the creation of alligator holes, which provide both wet and dry habitats for other organisms." https://en.wikipedia.org/wiki/Ecosystem_engineer https://en.wikipedia.org/wiki/Ecosystem_engineer Down in "ecology and behavior" for American Alligator, we have "Alligators modify wetland habitats, most dramatically in flat areas such as the Everglades, by constructing small ponds known as alligator holes. This behavior has qualified the American alligator to be considered a keystone species. Alligator holes retain water during the dry season and provide a refuge for aquatic organisms. Aquatic organisms that survive the dry season by seeking refuge in alligator holes are a source of future populations. The construction of nests along the periphery of alligator holes, as well as a buildup of soils during the excavation process, provide drier areas for other reptiles to nest and a place for plants that are intolerant of inundation to colonize. Alligator holes are an oasis during the Everglades dry season, so are consequently important foraging sites for other organisms. In the limestone depressions of cypress swamps, alligator holes tend to be large and deep, while those in marl prairies and rocky glades are usually small and shallow, and those in peat depressions of ridge and slough wetlands are more variable." and "Alligators also may control the long-term vegetation dynamics in wetlands by reducing the population of small mammals, particularly coypu, which may otherwise overgraze marsh vegetation. In this way, the vital ecological service they provide may be important in reducing rates of coastal wetland losses in Louisiana. They may provide a protection service for water birds nesting on islands in freshwater wetlands. Alligators prevent predatory mammals from reaching island-based rookeries and in return eat spilled food and birds that fall from their nests." So basically, alligators dig holes, and this does a bunch of important things, and also they eat one of the main animals that would otherwise destroy wetlands.
- giardini 10y ago
  Mz: "So basically, alligators dig holes, and this does a bunch of important things, and also they eat one of the main animals that would otherwise destroy wetlands." Well, that's not what you originally said. Furthermore you're misinterpreting what you quote above too. FWIW in the U.S. the word "coypu" is rarely used, we use the word "nutria" instead. First of all, to say Mz: "...like an alligator making swamps in the American South..." is like saying that cows make cow pastures, or prairie dogs make grasslands, or oysters make the seabeds that they lie in - it is essentially incorrect. I lived decades in the American South and have seen my share of alligators. I even raised one awhile and she did not terraform the backyard in any manner whatsoever. Mostly she crapped, irritated the dog, hissed and stood her ground until fed. To read someone speaking of alligators "making swamps in the American South" still has me laughing. Mz: "Removing alligators from certain swamps would, in fact, significantly impact the swamp and make it much more likely to revert to solid land over time." No. The swamp would be there with or w/o alligators. For example, Disney is removing alligators from their Disneyland parks. The swampy areas won't dry up as a result. Swamps are consequences of geography and climate, not of alligators. There are plenty of swamps w/o alligators and alligators w/o swamps (e.g., lakes, rivers, etc.). Humans are probably the main predators of nutria. Humans introduced nutria to the U.S. for their fur, in some instances, and to control various wild grasses, in others. Were the alligators were all gone, I have no doubt that other predators would easily pick up the slack. Even if the nutria were allowed to reproduce unencumbered, they would not "destroy wetlands". Firstly the population would, as in the usual predator-prey models, boom then bust. Secondly, as I said earlier, the wetlands are a product not of biology, but of geography and climate. Of course biology diversifies the environment, but it doesn't create it. You could hit Louisiana with a giant neutron bomb, killing every living thing there and the wetlands would remain for eons.
  - Mz 10y ago
    My understanding is that large swamps, like the Everglades would, in fact, shrink and stop being large, stable swamps without alligators. I am not going to try to dig up further supporting links showing that as sediment accumulates, wetlands change. Your pet alligator failing to terraform your backyard is not evidence that they do not have this impact in the wild. That is like saying "I have seen a single lion in the zoo. I can assure you, they don't hunt in groups." Anyway, I am done with this discussion. I believe my observation is accurate. If you don't want to believe it, so be it.

Mz 10y ago

Certainly they alter their environment Yes, that is what I meant. They alter their environment. I didn't intend to suggest that if you stick alligators in a non-swampy area, they create swamps by their very presence. Removing alligators from certain swamps would, in fact, significantly impact the swamp and make it much more likely to revert to solid land over time. Here are a few things my son looked up for me just this morning because we were discussing the topic: https://en.wikipedia.org/wiki/Alligator https://en.wikipedia.org/wiki/Alligator In 'Habitat' we have: "When [Alligators] construct alligator holes in the wetlands, they increase plant diversity and provide habitat for other animals during droughts." "Further west, in Louisiana, heavy grazing by coypu and muskrat are causing severe damage to coastal wetlands. Large alligators feed extensively on coypu, and provide a vital ecological service by reducing coypu numbers." https://en.wikipedia.org/wiki/American_alligator https://en.wikipedia.org/wiki/American_alligator At the very top of the page we have "They play an important role as ecosystem engineers in wetland ecosystems through the creation of alligator holes, which provide both wet and dry habitats for other organisms." https://en.wikipedia.org/wiki/Ecosystem_engineer https://en.wikipedia.org/wiki/Ecosystem_engineer Down in "ecology and behavior" for American Alligator, we have "Alligators modify wetland habitats, most dramatically in flat areas such as the Everglades, by constructing small ponds known as alligator holes. This behavior has qualified the American alligator to be considered a keystone species. Alligator holes retain water during the dry season and provide a refuge for aquatic organisms. Aquatic organisms that survive the dry season by seeking refuge in alligator holes are a source of future populations. The construction of nests along the periphery of alligator holes, as well as a buildup of soils during the excavation process, provide drier areas for other reptiles to nest and a place for plants that are intolerant of inundation to colonize. Alligator holes are an oasis during the Everglades dry season, so are consequently important foraging sites for other organisms. In the limestone depressions of cypress swamps, alligator holes tend to be large and deep, while those in marl prairies and rocky glades are usually small and shallow, and those in peat depressions of ridge and slough wetlands are more variable." and "Alligators also may control the long-term vegetation dynamics in wetlands by reducing the population of small mammals, particularly coypu, which may otherwise overgraze marsh vegetation. In this way, the vital ecological service they provide may be important in reducing rates of coastal wetland losses in Louisiana. They may provide a protection service for water birds nesting on islands in freshwater wetlands. Alligators prevent predatory mammals from reaching island-based rookeries and in return eat spilled food and birds that fall from their nests." So basically, alligators dig holes, and this does a bunch of important things, and also they eat one of the main animals that would otherwise destroy wetlands.

giardini 10y ago
Mz: "So basically, alligators dig holes, and this does a bunch of important things, and also they eat one of the main animals that would otherwise destroy wetlands." Well, that's not what you originally said. Furthermore you're misinterpreting what you quote above too. FWIW in the U.S. the word "coypu" is rarely used, we use the word "nutria" instead. First of all, to say Mz: "...like an alligator making swamps in the American South..." is like saying that cows make cow pastures, or prairie dogs make grasslands, or oysters make the seabeds that they lie in - it is essentially incorrect. I lived decades in the American South and have seen my share of alligators. I even raised one awhile and she did not terraform the backyard in any manner whatsoever. Mostly she crapped, irritated the dog, hissed and stood her ground until fed. To read someone speaking of alligators "making swamps in the American South" still has me laughing. Mz: "Removing alligators from certain swamps would, in fact, significantly impact the swamp and make it much more likely to revert to solid land over time." No. The swamp would be there with or w/o alligators. For example, Disney is removing alligators from their Disneyland parks. The swampy areas won't dry up as a result. Swamps are consequences of geography and climate, not of alligators. There are plenty of swamps w/o alligators and alligators w/o swamps (e.g., lakes, rivers, etc.). Humans are probably the main predators of nutria. Humans introduced nutria to the U.S. for their fur, in some instances, and to control various wild grasses, in others. Were the alligators were all gone, I have no doubt that other predators would easily pick up the slack. Even if the nutria were allowed to reproduce unencumbered, they would not "destroy wetlands". Firstly the population would, as in the usual predator-prey models, boom then bust. Secondly, as I said earlier, the wetlands are a product not of biology, but of geography and climate. Of course biology diversifies the environment, but it doesn't create it. You could hit Louisiana with a giant neutron bomb, killing every living thing there and the wetlands would remain for eons.
- Mz 10y ago
  My understanding is that large swamps, like the Everglades would, in fact, shrink and stop being large, stable swamps without alligators. I am not going to try to dig up further supporting links showing that as sediment accumulates, wetlands change. Your pet alligator failing to terraform your backyard is not evidence that they do not have this impact in the wild. That is like saying "I have seen a single lion in the zoo. I can assure you, they don't hunt in groups." Anyway, I am done with this discussion. I believe my observation is accurate. If you don't want to believe it, so be it.