<p>As with many situations there are positives and negatives. With bush encroachment the positives include expanding the range of native species, acting as a carbon sink, it can lead to natural reforestation. It can also increase the habitat for certain animals and potentially reduce erosion and help limit desertification. There is also the potential to increase ground cover, cool the land surface and retain soil moisture. In some situations it can even reduce the height of the water table and thus reduce salinity  of the land by keeping salt deeper down, below the depth to which plant root go down.</p>
<p>On the negative side of things, increasing bush cover reduces the amount of savanna in a region. Some animals depend on savanna for survival and thus encroachment of bush would be detrimental to them because it reduces their habitat, which in turn alters the dynamics of fauna in the region.</p>
<p>In the long term, in certain situations, this can turn out to be detrimental overall if the numbers of predator species are reduced too much and the number of prey species can become too much and they could overgraze an area ultimately leading to desertification and erosion. It all depends on the species affected by bush encroachment.</p>
<p>Additionally, changing a landscape from savanna to bush increases the potential for more destructive wildfires. Wooded landscapes burn at higher temperatures, which can affect the nutrient levels of soil, produce large burn scars which could increase the possibility of desertification and it can lead to a greater loss of life of flora and fauna.</p>

CC BY-SA 4.0
2023-02-18T04:02:41.150Z
There is also the bad of wiping out a native ecosystem, just replacing a lost ecosystem with another dos not change the fact you are talking about widespread extinction.
John
CC BY-SA 4.0
2023-02-16T11:59:30.137Z
2023-02-16T12:19:29.300Z
2023-02-16T12:19:29.300Z
Fred
<p>This answer is based on my knowledge on the tundra regime, where bush/shrub encroachment is also happening.</p>
<p>In these areas the expansion of shrub coverage replaces existing vegetation such as lichen and moss-dominated plant communities leading which causes large changes in tundra biome.</p>
<p>Although the shrub vegetation itself acts as a carbon sink the effect of vegetation change causes decreases albedo e.g., the darker shrub vegetation absorbs warmth from the sunlight compared to the lighter lichens, mosses, bare ground (and plain snow-cover) that reflect the solar radiance. Thus the effect of shrub encroachment can have warming effect on the climate (that may or may not exceed the increased carbon sink of shrub vegetation, still under a debate I think).</p>
<p>Wildfires were already mentioned, but they might increase also in the northern areas. In addition, the ground temperatures and thus microbial activity could change, leading for example to a increased decomposition and nutrient cycling.</p>
<p>For tundra ecosystems see f.e. Shrub expansion in tundra ecosystems:
dynamics, impacts and research priorities (2011). Myers-Smith et. Environ. Res. Lett. 6 (2011) 045509</p>

CC BY-SA 4.0
2023-02-17T09:09:53.757Z
2023-02-17T09:09:53.757Z
Teemu Juselius
<p>From what I've read about <a href="https://en.wikipedia.org/wiki/Woody_plant_encroachment" rel="nofollow noreferrer">bush encroachment</a>, it is most often made to sound as a <a href="https://phys.org/news/2023-02-high-intensity-reverse-bush-encroachment-african.html" rel="nofollow noreferrer">bad thing</a>, potentially as a symptom of land degradation. This sounds counterintuitive to me because bush encroachment actually consists of</p>
<ol>
<li>the expansion of native (as opposed to invasive) plant species, and</li>
<li>serves as a carbon sink.</li>
</ol>
<p>If anything, it sounds like an ideal case of nature reclaiming its rights, so why would it be a bad thing from a conservation point of view?</p>

<climate-change><environmental-protection><ecology><vegetation>
Why is bush encroachement a bad thing?
Tfovid
# Why is bush encroachement a bad thing?

(Asked by: username_0 on 2023-02-16)

From what I've read about [bush encroachment](https://en.wikipedia.org/wiki/Woody_plant_encroachment), it is most often made to sound as a [bad thing](https://phys.org/news/2023-02-high-intensity-reverse-bush-encroachment-african.html), potentially as a symptom of land degradation. This sounds counterintuitive to me because bush encroachment actually consists of

1. the expansion of native (as opposed to invasive) plant species, and
2. serves as a carbon sink.

If anything, it sounds like an ideal case of nature reclaiming its rights, so why would it be a bad thing from a conservation point of view?

**Tags:** climate-change, environmental-protection, ecology, vegetation


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## 2 answers

### Answer by username_1 on 2023-02-16. Score: 2

As with many situations there are positives and negatives. With bush encroachment the positives include expanding the range of native species, acting as a carbon sink, it can lead to natural reforestation. It can also increase the habitat for certain animals and potentially reduce erosion and help limit desertification. There is also the potential to increase ground cover, cool the land surface and retain soil moisture. In some situations it can even reduce the height of the water table and thus reduce salinity of the land by keeping salt deeper down, below the depth to which plant root go down.

On the negative side of things, increasing bush cover reduces the amount of savanna in a region. Some animals depend on savanna for survival and thus encroachment of bush would be detrimental to them because it reduces their habitat, which in turn alters the dynamics of fauna in the region.

In the long term, in certain situations, this can turn out to be detrimental overall if the numbers of predator species are reduced too much and the number of prey species can become too much and they could overgraze an area ultimately leading to desertification and erosion. It all depends on the species affected by bush encroachment.

Additionally, changing a landscape from savanna to bush increases the potential for more destructive wildfires. Wooded landscapes burn at higher temperatures, which can affect the nutrient levels of soil, produce large burn scars which could increase the possibility of desertification and it can lead to a greater loss of life of flora and fauna.

> **Comments:**
> **username_2**: There is also the bad of wiping out a native ecosystem, just replacing a lost ecosystem with another dos not change the fact you are talking about widespread extinction.  

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### Answer by username_3 on 2023-02-17. Score: 1

This answer is based on my knowledge on the tundra regime, where bush/shrub encroachment is also happening.

In these areas the expansion of shrub coverage replaces existing vegetation such as lichen and moss-dominated plant communities leading which causes large changes in tundra biome.

Although the shrub vegetation itself acts as a carbon sink the effect of vegetation change causes decreases albedo e.g., the darker shrub vegetation absorbs warmth from the sunlight compared to the lighter lichens, mosses, bare ground (and plain snow-cover) that reflect the solar radiance. Thus the effect of shrub encroachment can have warming effect on the climate (that may or may not exceed the increased carbon sink of shrub vegetation, still under a debate I think).

Wildfires were already mentioned, but they might increase also in the northern areas. In addition, the ground temperatures and thus microbial activity could change, leading for example to a increased decomposition and nutrient cycling.

For tundra ecosystems see f.e. Shrub expansion in tundra ecosystems:
dynamics, impacts and research priorities (2011). Myers-Smith et. Environ. Res. Lett. 6 (2011) 045509


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