Indigenous biodiversity

I have 1,612 verified observations on iNaturalist between Auckland and Whangarei documenting 552 species (mostly invertebrates) covering forest, freshwater, intertidal and marine habitats. I don't take many photographs of plants. Of these observation 96 or 17% of species were introduced. Here is a break down showing areas where I have found more or less introduced species:

Hauturu Aotea Tawharanui East Auckland Waitakeres Hunua Ranges Rangitoto / Motutapu / Motuihe Motukorea Mungatapere
Observations 206 149 141 197 77 94 71 33 159
Species 86 84 86 120 57 64 52 25 83
Introduced 6 12 8 35 1 4 11 4 9
Percent introduced 7 14 9 29 2 6 21 16 11

I expected the restored and protected islands in the Hauraki Gulf to have a smaller percent of introduced species. I think the high number of introduced species (compared to the Waitakeres and the Hanua Ranges) reflects the islands farmed history with islands like Motukorea and Motutapu still dominated by kikuyu. The larger and older the forest the more indigenous biodiversity.

Posted on September 24, 2019 09:02 PM by shaun-lee shaun-lee

Comments

Hi Shaun,

This is really cool to have broken everything out like this. What are you using as your boundary? For example are you using Tawharanui's regional park boundary or the peninsula? I'd be curious to see how the percentage of native to introduced species changes as you keep adding observations to a given area.

Wyatt

Posted by wyattd over 4 years ago

Thanks Wyatt. It's not very scientific as I am just using the rectangle provided by the map to roughly carve out my observations in an area. Most of my observations at Tawh have been in Eco bush and Takatu Point with marine ones at Jones Bay and Anchor Bay. One would get a better understanding by looking at everyones observations but for this little study I have just used my own observations in areas I know. You can filter by date to compare changes over time, iNat is going to be an amazing resource as it grows.

Posted by shaun-lee over 4 years ago

I always tell my coworkers that iNat gets more and more powerful everyday. It is such an amazing database and tool.

Posted by wyattd over 4 years ago

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