The truth about the TMA's plantings at Ōtāhuhu Mt Richmond

New plantings - 2024

Two-year-old plantings - 2023

Tūpuna Maunga Authority tries to justify its tree felling intentions by saying they're planting thousands of natives at each maunga. Yet neither journalists nor Auckland Council’s elected representatives have unpicked just what those thousands actually are or how impressive that number actually is. We suspect few of the TMA's members know either.

There has only been a little bit of new planting at Ōwairaka Mt Albert since we wrote our planting analysis blog for that maunga in late 2021, so let's instead look at recent Ōtāhuhu Mt Richmond plantings. As you may recall, the Authority felled around 60 trees there last year and would have felled up to 218 more by now had it not been for Shirley Waru's judicial action. Over time the Authority intends to fell up to 443 trees at that maunga - 75% of its entire tree cover. When trying to defend the felling they say they will be planting around 39,000 natives to "replace" the exotics. That sounds impressive on face value but we were curious to know exactly that meant, so put in an official information request to find out more.

It took more than five months and the Ombudsman's intervention before the Authority released this information. Unfortunately, we are increasingly having to rely on Ombudsman intervention to get requested information from TMA even though the law requires official information requests are met within 20 working days. Anyway, here's what we now know:

The cost of felling around 60 trees in 2023 was at least $384,947 for TreeScape and security. On top of that will be third party costs for preparing reports and resource consent applications, TMA staff time, etc. So the true costs will far higher than what is stated here.

2023 planting season budget - 10,803 native plants: $60,548 ($23,273 for plants, and $37,275 for mulch and planting). Analysis shows only 72 of those plants have the potential to grow to 18 m or more in the decades they will take to reach maturity - assuming they all survive. 

2024 planting season budget - 7197 native plants: $38,741 ($28,216 for plants and $10,525 for mulching costs). Analysis shows only 87 of those have the potential to grow to 18 m or more at maturity. Most of those tall tree species are the slow-growing kahikitea, which will take 50 years or more to grow higher than 18 m.

These plantings represent nearly half of the total intended plantings. As you can see above and in the tables below, only 159 of those plants have the potential to grow 18 metres or more at maturity - that’s less than 1% of the total (0.88333333333333% to be precise). We also ran the numbers for species that could potentially grow to 16 m and found that only added another 35 trees. This recalculation showed species that might grow to 16 m or more represented in a tad over 1% of the total plantings. No matter how one looks at it, this is not an impressive number of tall tree species plantings.

The Authority also advised it spent $17,202 on plantings in the 2022 season but didn't provide details of what they were. Based on the figures above, one could assume that accounted for maybe 3000 plants of which maybe 25-30 have the potential to grow to tall trees.

Based on the costs that we know, it looks like the TMA could end up spending at least $3 million at 2024 prices to fell up to 443 trees at that maunga and just over $1 million to plant. Yet almost all of the current and intended plantings are on different parts of the maunga to where the exotics are, so there's no reason why the exotics can't be retained alongside the new plantings and the $3 million instead put into something that's positive (for people and wildlife alike), constructive and unifying.

And one last thing: Let's now compare the Authority's grand sounding intentions to plant 39,000 natives at Ōtāhuhu Mt Richmond with Tiritirimatangi (which has around 60% forest cover). Up to 300,000 natives were planted on the island over a 10-year period. Taking size differences into account, the TMA would need to plant up to 288,000 natives at Ōtāhuhu Mt Richmond to come anywhere close to Tiri. And far more of those would need to be tall tree species.

The pink areas are where trees are to be felled on the maunga - up to 75% of that entire tree cover will go, according to the Authority’s plans.

The green areas are where the new plantings are / will be. Note that the circular green patch at the top is where the Authority felled more than 100 olive trees in 2019.