5 ms·

why not plant other species to out-compete the invasive ones? why do we need to perform chemotherapy on our forests?

drone 3y ago
Only one of the trees I listed was invasive, the others are opportunistic natives to their regions that will outgrow everything else. The nice "diverse" forest you're thinking of in your mind took a long time to become that way, the normal state of nature is to not create a perfect balance out of the gate, but for constant competition and regularly have to cycle through multiple iterations of configuration which are, by all means, not as productive or valuable for wildlife/nature as their final states. None of that means that using a herbicide is sufficient, but without, you're looking at potentially hundreds of years to get back a usable environment for wildlife that is well-balanced vs 10's of years. Outside of a few soil-active herbicides, most of what they use is one-and-done and can be applied selectively to only problem plants with minimal unintended consequences.
- anon84873628 3y ago
  To elaborate on this great answer, the technical term is "ecological succession", defined on Wikipedia as "the process of change in the species that make up an ecological community over time." Plants do not just fill their niche, they alter the environment over time, which in aggregate alters the ecosystem as a whole. Animals and microbes also play a role in this process. E.g. the way rodents and birds disperse seeds, or how pests can destroy a species, or even how elephants can uproot whole trees.
- hutzlibu 3y ago
  Where I live in germany, there used to be extensive spruce monocultures forests everywhere. They are mostly chopped down now and replaced with a mixed young forest, all without herbicides. (But with some planted trees, cleansing and fences to protect the young forest from deers) So after 15 years they surely are not comparible to old grown forests, but they are very diverse and alive. So I strongly question the assumption that herbicides are necessary or beneficial to create a diverse forest. Most of the dominating species in the first years will be (were) replaced by something else eventually.
  - drone 3y ago
    To be clear: herbicides are not essential in every area, but in some areas it is completely cost-ineffective to promote appropriate diversity and wildlife habitat without some use of it. FWIW, in the region I'm currently managing a 100-acre habitat that was previously a pine plantation, it would be sacrosanct to "fence out deer." Early stage re-growth is wonderful deer habitat, lots of sunlight generates lots of forbs. However, in the same region I am in, any area left to its own devices becomes quickly overgrown to the point of making poor habitat for wildlife (no viable food, no viable cover, even though it's "thick" it is not useful to species such as deer, rabbits, quail, turkeys, etc. lacking the right kinds of food and cover). Mechanical and fire (prescribed burns) are our primary tool we use, along with appropriate canopy thinning. However, when dealing with opportunistic species (the most aggressive here being sweetgum and chinese tallow), these methods are not effective. As each of these species re-sprout and spread via roots as well as seed, mechanical and fire only top-kill, resulting in them coming back thicker again within months. Repeated mechanical control presents significant issues both for valuable forb and impacts on land (a skid-steer is very heavy and results in significant compaction of soil, for example) and is incredibly expensive at about $1,000/acre when following proper selective practices. We were also very much against the use of herbicides, but after numerous conversations with local biologists and forestry management professionals (our state provides them as a service), we finally realized that we were in a losing battle and selective application was the way to go. With basal spraying for larger stems of unwanted species and selective foliar for seedlings, we've reduced our costs to a fraction, reduced the damage to land and erosion, and we're seeing higher value (ecologically, not monetary) habitat with a faster turn time. Our approach is to eliminate all non-native, invasive species, develop the mix of pine savannah and hardwood bottoms our region has historically represented, and we're seeing the returns we expected much quicker than mechanical methods were providing us. None of the "chemicals" we use are soil-active, and all of them have a half-life measured in days. We don't use them where girdling or sawing are sufficient to open canopy or create snags, and we don't broadly apply them. I'm glad you live in a region where there are no opportunistic trees and shrubs which will crowd out other species, and where mechanical control is sufficient to restore traditional diversity, but alas, it still doesn't have the same reward everywhere. Anything left to its own devices in this region will rapidly, I mean within 5 years, become what we call the "pine curtain," useless to both wildlife and man. For centuries even the indigenous tribes had to practice regular controlled burning to fight this.
- thaumasiotes 3y ago
  > the normal state of nature is to not create a perfect balance out of the gate That is true. Additionally, a balance will never be achieved no matter how long you wait, either. That's the state of nature; some things are always replacing other things.
  - RGamma 3y ago
    That's dangerously simplistic, see https://en.wikipedia.org/wiki/Ecological_stability https://en.wikipedia.org/wiki/Ecological_stability and related topics for a start.
    - thaumasiotes 3y ago
      Ecological stability refers to a concept that is never realized. You can pretend it exists by ignoring the variation that you feel is unimportant. Over time, that variation will make its way into the areas that you thought were stable.
      - RGamma 3y ago
        The reason I wrote my remark is the relatively recent uptick in "in nature everything always changed regardless of whether we exist, therefore we're absolved from everything that's happening with the biosphere"-style arguments. Obviously on the face of it the premise is true, but time scales, operationalisation and causes/responsibilities matter critically there. Islands of stability exist (like our homeostatic bodies, species that have survived for millions of years, old growth forests, etc) in nature. But whether one cares about (not unnecessarily, prematurely ending) any of this is a very different matter.
        thaumasiotes 3y ago
        > species that have survived for millions of years I mean, this is a perfect example of pretending that differences don't exist because you can't see them. There are no such species. https://www.darklegacycomics.com/185 https://www.darklegacycomics.com/185

Only one of the trees I listed was invasive, the others are opportunistic natives to their regions that will outgrow everything else. The nice "diverse" forest you're thinking of in your mind took a long time to become that way, the normal state of nature is to not create a perfect balance out of the gate, but for constant competition and regularly have to cycle through multiple iterations of configuration which are, by all means, not as productive or valuable for wildlife/nature as their final states. None of that means that using a herbicide is sufficient, but without, you're looking at potentially hundreds of years to get back a usable environment for wildlife that is well-balanced vs 10's of years. Outside of a few soil-active herbicides, most of what they use is one-and-done and can be applied selectively to only problem plants with minimal unintended consequences.

anon84873628 3y ago
To elaborate on this great answer, the technical term is "ecological succession", defined on Wikipedia as "the process of change in the species that make up an ecological community over time." Plants do not just fill their niche, they alter the environment over time, which in aggregate alters the ecosystem as a whole. Animals and microbes also play a role in this process. E.g. the way rodents and birds disperse seeds, or how pests can destroy a species, or even how elephants can uproot whole trees.
hutzlibu 3y ago
Where I live in germany, there used to be extensive spruce monocultures forests everywhere. They are mostly chopped down now and replaced with a mixed young forest, all without herbicides. (But with some planted trees, cleansing and fences to protect the young forest from deers) So after 15 years they surely are not comparible to old grown forests, but they are very diverse and alive. So I strongly question the assumption that herbicides are necessary or beneficial to create a diverse forest. Most of the dominating species in the first years will be (were) replaced by something else eventually.
- drone 3y ago
  To be clear: herbicides are not essential in every area, but in some areas it is completely cost-ineffective to promote appropriate diversity and wildlife habitat without some use of it. FWIW, in the region I'm currently managing a 100-acre habitat that was previously a pine plantation, it would be sacrosanct to "fence out deer." Early stage re-growth is wonderful deer habitat, lots of sunlight generates lots of forbs. However, in the same region I am in, any area left to its own devices becomes quickly overgrown to the point of making poor habitat for wildlife (no viable food, no viable cover, even though it's "thick" it is not useful to species such as deer, rabbits, quail, turkeys, etc. lacking the right kinds of food and cover). Mechanical and fire (prescribed burns) are our primary tool we use, along with appropriate canopy thinning. However, when dealing with opportunistic species (the most aggressive here being sweetgum and chinese tallow), these methods are not effective. As each of these species re-sprout and spread via roots as well as seed, mechanical and fire only top-kill, resulting in them coming back thicker again within months. Repeated mechanical control presents significant issues both for valuable forb and impacts on land (a skid-steer is very heavy and results in significant compaction of soil, for example) and is incredibly expensive at about $1,000/acre when following proper selective practices. We were also very much against the use of herbicides, but after numerous conversations with local biologists and forestry management professionals (our state provides them as a service), we finally realized that we were in a losing battle and selective application was the way to go. With basal spraying for larger stems of unwanted species and selective foliar for seedlings, we've reduced our costs to a fraction, reduced the damage to land and erosion, and we're seeing higher value (ecologically, not monetary) habitat with a faster turn time. Our approach is to eliminate all non-native, invasive species, develop the mix of pine savannah and hardwood bottoms our region has historically represented, and we're seeing the returns we expected much quicker than mechanical methods were providing us. None of the "chemicals" we use are soil-active, and all of them have a half-life measured in days. We don't use them where girdling or sawing are sufficient to open canopy or create snags, and we don't broadly apply them. I'm glad you live in a region where there are no opportunistic trees and shrubs which will crowd out other species, and where mechanical control is sufficient to restore traditional diversity, but alas, it still doesn't have the same reward everywhere. Anything left to its own devices in this region will rapidly, I mean within 5 years, become what we call the "pine curtain," useless to both wildlife and man. For centuries even the indigenous tribes had to practice regular controlled burning to fight this.
thaumasiotes 3y ago
> the normal state of nature is to not create a perfect balance out of the gate That is true. Additionally, a balance will never be achieved no matter how long you wait, either. That's the state of nature; some things are always replacing other things.
- RGamma 3y ago
  That's dangerously simplistic, see https://en.wikipedia.org/wiki/Ecological_stability https://en.wikipedia.org/wiki/Ecological_stability and related topics for a start.
  - thaumasiotes 3y ago
    Ecological stability refers to a concept that is never realized. You can pretend it exists by ignoring the variation that you feel is unimportant. Over time, that variation will make its way into the areas that you thought were stable.
    - RGamma 3y ago
      The reason I wrote my remark is the relatively recent uptick in "in nature everything always changed regardless of whether we exist, therefore we're absolved from everything that's happening with the biosphere"-style arguments. Obviously on the face of it the premise is true, but time scales, operationalisation and causes/responsibilities matter critically there. Islands of stability exist (like our homeostatic bodies, species that have survived for millions of years, old growth forests, etc) in nature. But whether one cares about (not unnecessarily, prematurely ending) any of this is a very different matter.
      - thaumasiotes 3y ago
        > species that have survived for millions of years I mean, this is a perfect example of pretending that differences don't exist because you can't see them. There are no such species. https://www.darklegacycomics.com/185 https://www.darklegacycomics.com/185