Introduction of biodiversity index
Introduction of biodiversity index
Posted by AaronClausen
17 Aug 2023
Hi everyone,
We are trialling a new concept called the biodiversity index.
The biodiversity index is a weighted score that provides an indicative value as to the general biodiversity of a given location.
The higher the number of threatened, rare and/or native species within a location, the higher it's biodiversity index will be.
Reporting more sightings of a species that already exists within a location will not influence its biodiversity index.
The biodiversity index for a given location is calculated by:
SUM ( weighted index of each species recorded at the location )
- Threatened and rare species attract the highest weighted index
- Native species attract a high weighted index
- Exotic and cosmopolitan species attract a low biodiversity index but still contribute a point
This is an initial attempt, or a starting point, to provide a consistent way to measure the biodiversity across different locations.
And I am certain that we won't have got it right first go.
The algorithm and weighted score used to calculate the biodiversity for each location is definitely open to feedback and improvement - but this is a starting point.
We are keen to see how it holds up and the kind of feedback that we get about this new feature.
Please comment below and let us know what you think!
What can we do with it?
The biodiversity index can provide a general indication that a location may either:
- Be data deficient and therefore need people to report more sightings; OR
- Be genuinely low in biodiversity and potentially a good candidate for regenerative or restorative efforts
We would like to measure the change in a location's biodiversity index over time (both good and bad).
Examples
With 78 species of native orchids, open forest, woodland and grassland reserve, Black Mountain, has an extremely high biodiversity index:
In contrast, an urban area such as Dickson, ACT, carries a much lower biodiversity index:
31 comments
AndyRoo
wrote:
17 Aug 2023
Great idea Aaron. Can you set up an info page which will also include more specifics on basis of the calculation formula/algorithm? What constitutes a "given location" area?
AaronClausen
wrote:
17 Aug 2023
Agree @MatthewFrawley!
Thanks @AndyRoo - yep I think we will be able to expand with more detailed info on how the calculation is made.
We are also working on a visual representation kind of like a spectrum, that will show the breakdown of species within each location to help visualise it a bit better.
re: what constitutes a given location - these are simply the existing locations (maps and places) that already exist in NatureMapr that we have a polygon or Google suburb definition of.
Thanks @AndyRoo - yep I think we will be able to expand with more detailed info on how the calculation is made.
We are also working on a visual representation kind of like a spectrum, that will show the breakdown of species within each location to help visualise it a bit better.
re: what constitutes a given location - these are simply the existing locations (maps and places) that already exist in NatureMapr that we have a polygon or Google suburb definition of.
RAllen
wrote:
18 Aug 2023
Fantastic. Would it be useful to be able to place a time frame on the index. Especially with more accumulated historic data showing trends over each decade.
mlech
wrote:
18 Aug 2023
Love this idea. Only issue I can see is consulting firms or others using this to determine value of an area that may have been extensively surveyed with data being held in ACT government databases. These areas could show lower.diversity than is actually known. Perhaps some of this data may need to be populated into CNM as well.
Mike
wrote:
18 Aug 2023
Great idea. There are more than 150 non-local Australian native plants already identified by the aeroplane symbol that should have an index between native and exotic. I will need to continue reporting plants I have already recorded, or the Biodiversity Index will go down with time.
kateSRS
wrote:
18 Aug 2023
I think the biodiversity index is a good idea. II would like to see it split into native and non-native but that is more work and possibly splitting hairs, though I think its the first question people will ask - what is the contribution of native and non-native species to a score in a given area. I also agree with a previous comment on sampling effort. It would be great to see this presented along with the index - it may give contributors incentive to sample the area.
MichaelBedingfield
wrote:
18 Aug 2023
Hi Aaron. This is a great idea. However, I have doubts about including "Places" in the index. This gives a misleading idea of the quality of urban areas. For example, the biodiversity index for Acton is 3628, which is much higher than Black Mountain Reserve with 2681, simply because much of Black Mountain is included in Acton. Similarly, Conder has an index of 2124, because it covers parts of Tuggeranong Hill (1596) & Rob Roy Reserve(1086). It is very misleading and even confusing to say the suburbs of Acton & Conder are better in biodiversity quality than the nature reserves. Also, the boundaries provided for Places by Google Maps are known to be inaccurate, sometimes very much so. So this would add to the inaccuracy of the index for Places.
Mike
wrote:
18 Aug 2023
Currently I can't see 'Places' but I agree with @michaelb. Isaacs Ridge Nature Reserve gets divided into Isaacs, Jerrabomberra and Symonston. I am not fussed that it excludes Isaacs Pines (but includes the Special Purpose Reserve) though the Pines include more diversity than some people expect. I was going to say that Conder would have a high index because of Michael's garden, but he says it is because of Tuggeranong Hill. The problem of Places is shown by the ACT Tree Coverage maps, which show Isaacs as having over 40% tree coverage because it includes Isaacs pines and the west tree-covered part of the Nature reserve.
MichaelBedingfield
wrote:
18 Aug 2023
Hi Mike. Places are still there. Use the Quick Search to find any suburb. Or click on the Place button on a sighting.
AaronClausen
wrote:
18 Aug 2023
Thanks guys, fantastic feedback - so:
- Don't display for places
- Provide an improved breakdown of value / calculation for each location
- Don't display for places
- Provide an improved breakdown of value / calculation for each location
mmackinnon
wrote:
18 Aug 2023
Great idea. What's needed. However, as you have written "....general indication that a location may either: Be data deficient and therefore need people to report more sightings; OR
Be genuinely low in biodiversity and potentially a good candidate for regenerative or restorative efforts", a low index may simply indicate paucity of data. So I would like to see two indices - one for data intensity and one for biodiversity - presented together somehow. These could be either two measures side by side or there could probably be a confidence measure attached to the biodiversity index and displayed accordingly, e.h.g., colour is biodiversity, size of dot or intensity of colour reflects confidence.
Be genuinely low in biodiversity and potentially a good candidate for regenerative or restorative efforts", a low index may simply indicate paucity of data. So I would like to see two indices - one for data intensity and one for biodiversity - presented together somehow. These could be either two measures side by side or there could probably be a confidence measure attached to the biodiversity index and displayed accordingly, e.h.g., colour is biodiversity, size of dot or intensity of colour reflects confidence.
AaronClausen
wrote:
18 Aug 2023
I like your thinking @mmackinnon - some great ideas there.
We are working on a visual spectrum style diagram next to show the breakdown and will continue to play with this feature based on user feedback like yours.
We are working on a visual spectrum style diagram next to show the breakdown and will continue to play with this feature based on user feedback like yours.
KMcCue
wrote:
18 Aug 2023
This might be a useful, independent measure of the impact of prescribed burns in Canberra Nature Park, a before and after biodiversity index.
RomanSoroka
wrote:
18 Aug 2023
A great concept Aaron. It would be good if the diversity index could be calculated for a Radar Search area.
MichaelBedingfield
wrote:
19 Aug 2023
I like the combination of biodiversity & data quantity measures. As an extra note Aaron, the email alerts for this conversation are not coming as they should be for announcements. As part of this conversation I should have received alerts from all comments after mine given above. but have not. This is a bug in the system.
MichaelBedingfield
wrote:
19 Aug 2023
Another thing on biodiversity:- Giving a point to very invasive weeds may not be such a good idea. And if for example there are the are >10,000 present for invasive weeds like St John's Wort or African Lovegrass it would be worth deducting some points from the score. Alternatively, you could have separate measures for native and exotic biodiversity, and give a higher score if the number of that species present is larger.
SenexRugosus
wrote:
19 Aug 2023
Interesting idea!
Is there an inverse weighting for land area? Or does the index get bigger as more places are aggregated into one? It would be interesting to see the biodiversity index displayed as a map of the whole region, colour-coded by the weighted sum of species per square km.
Is there an inverse weighting for land area? Or does the index get bigger as more places are aggregated into one? It would be interesting to see the biodiversity index displayed as a map of the whole region, colour-coded by the weighted sum of species per square km.
Mike
wrote:
19 Aug 2023
@michaelb, CNM already has categories for minor, medium and major pests so it could be easy to give (or subtract) points for them. However, there needs to be some way of adjusting for abundance.
@SenexRugosus asks about land area, and in general biodiversity increases with area or different habitat such as creeks and ponds. The ACT Government has vegetation maps that might be useful but I don’t think they could be used with Google.
@SenexRugosus asks about land area, and in general biodiversity increases with area or different habitat such as creeks and ponds. The ACT Government has vegetation maps that might be useful but I don’t think they could be used with Google.
MichaelBedingfield
wrote:
19 Aug 2023
Thanks @Mike & @SenexRugosus - I agree that land area should be considered a well.
lbradley
wrote:
19 Aug 2023
Is there a biodiversity index for Aranda Bushland, and if so, where can I find it?
I think the biodiversity index is a great idea. I’m not sure about adding anything for non indigenous plants. I would like to see a biodiversity index for only plants that are indigenous to the location.
I think the biodiversity index is a great idea. I’m not sure about adding anything for non indigenous plants. I would like to see a biodiversity index for only plants that are indigenous to the location.
lbradley
wrote:
19 Aug 2023
Nevermind. I found the biodiversity index for AB. It’s 2,887 which is higher than Black Mountain. 😊
AndyRoo
wrote:
21 Aug 2023
Interesting to seeing all the feedback and variety of ideas that have emerged. I agree with @mmackinnon's idea of having two indices - one for biodiversity (native focussed as per @lbradley's thoughts) and one for data quantity/richness. I'm sure Michael Mulvaney, given his experience, will have some useful ideas/input, particularly regarding the biodiversity index.
The biodiversity index as currently proposed appears to be focussed on native species richness (and possibly abundance) and threatened species. However, in practice when assessing the biodiversity value of a site there are a multiplicity of other factors (which I won't list here) that are required to be taken into consideration, some of which have been touched on in the various comments above. These many factors aren't captured in NatureMapr and it would probably be impractical to do so given the additional levels complexity and effort it would introduce for the software and admin teams and given the additional levels of contributor effort, knowledge, and data access that would be required. Therefore, I would also suggest that the name of the biodiversity index should also better reflect that it is only capturing one or a few elements of site biodiversity value, even if in many instances these may be the most significant for conservation protection and management purposes. For starters, here are four suggestions:
*Native species biodiversity index
*Native species richness index
*Native species value index
*Native species diversity index
The biodiversity index as currently proposed appears to be focussed on native species richness (and possibly abundance) and threatened species. However, in practice when assessing the biodiversity value of a site there are a multiplicity of other factors (which I won't list here) that are required to be taken into consideration, some of which have been touched on in the various comments above. These many factors aren't captured in NatureMapr and it would probably be impractical to do so given the additional levels complexity and effort it would introduce for the software and admin teams and given the additional levels of contributor effort, knowledge, and data access that would be required. Therefore, I would also suggest that the name of the biodiversity index should also better reflect that it is only capturing one or a few elements of site biodiversity value, even if in many instances these may be the most significant for conservation protection and management purposes. For starters, here are four suggestions:
*Native species biodiversity index
*Native species richness index
*Native species value index
*Native species diversity index
KylieWaldon
wrote:
23 Aug 2023
I think using the data for something is better than using it for nothing. Its worth a trial. If it doesn't pan out that's fine, at least you gave it a go.
AaronClausen
wrote:
1 Sep 2023
Hi everyone,
Thanks for the fantastic and energetic feedback on this.
We have removed the biodiversity index from Places (E.g. Dickson, ACT) and from Survey Points.
So the index will now only be displayed for Maps (aka polygons).
We will soon look to introduce some kind of measurement of the density and coverage of sighting data for a given Map (polygon) to accompany the biodiversity index.
@roman_soroka - we may be able to display the index for a map search in the future - excellent idea.
@michaelb - yep hopefully another accompanying number soon to give an indication of "data saturation/density" for given map/polygon.
@eltrixo is also working on a visual spectrum style breakdown which we will release soon that will show the breakdown of species that exist within a given location.
Thanks for the fantastic and energetic feedback on this.
We have removed the biodiversity index from Places (E.g. Dickson, ACT) and from Survey Points.
So the index will now only be displayed for Maps (aka polygons).
We will soon look to introduce some kind of measurement of the density and coverage of sighting data for a given Map (polygon) to accompany the biodiversity index.
@roman_soroka - we may be able to display the index for a map search in the future - excellent idea.
@michaelb - yep hopefully another accompanying number soon to give an indication of "data saturation/density" for given map/polygon.
@eltrixo is also working on a visual spectrum style breakdown which we will release soon that will show the breakdown of species that exist within a given location.
MichaelBedingfield
wrote:
1 Sep 2023
Hi @AaronClausen - will you be giving an index for both native biodiversity and exotic biodiversity?
@rainer (Rainer Rehwinkel) spent years evaluating sites for conservation purposes. His guidance in developing a good measure of biodiversity would be valuable.
@rainer (Rainer Rehwinkel) spent years evaluating sites for conservation purposes. His guidance in developing a good measure of biodiversity would be valuable.
rainer
wrote:
1 Sep 2023
Thanks @michaelb, I have indeed spent some time developing indices for assessing biodiversity. I have developed a floristic value score (FVS) methodology for grassy ecosystems for ACT and across NSW.
As a first principle, any score, to be comparable, needs to be area-constrained. It would be very difficult to have a meaningful comparison between, say, a large megadiverse site like Black Mountain, with a small site such as, say, the small grassland site at Reservoir Hill at Lawson. Also, the amount of effort in gaining information about a site is important. To be meaningful, each score for a site needs to have an indication as to how much survey effort has been expended and the area that has been covered.
Also important is the idea that it is not just species richness that is important, but the bigger concept of “diversity”. Two sites may have the same species richness (i.e., the same number of species) but differ in diversity, by the fact that in one site, lets say of the ten species present, one species dominates and the other species are all rare, while in the second site, each of the ten species are more or less equally common. The second site is said to be more diverse.
These are factors that are built in to the FVS. Also built into this system is the idea that some species are rarer than others. Such species are weighted higher and contribute a greater amount to the final score for each plot.
As a first principle, any score, to be comparable, needs to be area-constrained. It would be very difficult to have a meaningful comparison between, say, a large megadiverse site like Black Mountain, with a small site such as, say, the small grassland site at Reservoir Hill at Lawson. Also, the amount of effort in gaining information about a site is important. To be meaningful, each score for a site needs to have an indication as to how much survey effort has been expended and the area that has been covered.
Also important is the idea that it is not just species richness that is important, but the bigger concept of “diversity”. Two sites may have the same species richness (i.e., the same number of species) but differ in diversity, by the fact that in one site, lets say of the ten species present, one species dominates and the other species are all rare, while in the second site, each of the ten species are more or less equally common. The second site is said to be more diverse.
These are factors that are built in to the FVS. Also built into this system is the idea that some species are rarer than others. Such species are weighted higher and contribute a greater amount to the final score for each plot.
rainer
wrote:
1 Sep 2023
Additionally, the FVS measures a weed vale score. This needs more work, but if developed more fully, could be used either alongside the native FVS value, or perhaps the WVS could be used to subtract from the FVS to provide an overall score.
rainer
wrote:
1 Sep 2023
The index you’ve presented is really just a species richness score. It coukd be presented as three separate scores.
The biodiversity index for a given location is calculated by:
SUM ( weighted index of each species recorded at the location )
Threatened and rare species attract the highest weighted index
Native species attract a high weighted index
Exotic and cosmopolitan species attract a low biodiversity index but still contribute a point
So, a score each for the following:
1. Number of threatened species
2. Total number of indigenous species
3. Total number of exotic and non-indigenous native species.
Additional information could be derived by dividing each of the above by the area of the in ha site to give an average for comparison purposes. These measures still do not take into account survey effort.
The biodiversity index for a given location is calculated by:
SUM ( weighted index of each species recorded at the location )
Threatened and rare species attract the highest weighted index
Native species attract a high weighted index
Exotic and cosmopolitan species attract a low biodiversity index but still contribute a point
So, a score each for the following:
1. Number of threatened species
2. Total number of indigenous species
3. Total number of exotic and non-indigenous native species.
Additional information could be derived by dividing each of the above by the area of the in ha site to give an average for comparison purposes. These measures still do not take into account survey effort.
AaronClausen
wrote:
5 Sep 2023
