Elaeagnus at Kaipatiki Creek
"Elaeagnus Block"
During 1997-98, Elaeagnus regrowth from an earlier 6-week chemical weed control operation was controlled manually by volunteers, but was also uncontrolled along part of the streamside then known as "Elaeagnus Block", as the dense mass made wading of the stream or walking its banks impossible over several metres of the stream's length.
In a recent observation from the roadside, a large area of 1997-99 Elaeagnus invasion appears to be still present above Elaeagnus Block, visible from just above the stream to halfway up the bank to the road:
Hidden from both bush walk and roadside by native canopy, this is the largest weed-dominated area we have observed along the stream so far in 2018-2019.
We have now accessed the streambank opposite this invasion and confirmed it as Elaeagnus. It does not appear to extend to the streamedge, possibly due to the depth and extent of Tradescantia below it. The Elaeagnus is itself invaded with Japanese honeysuckle. The streamedge is very weedy here, with several clumps of ginger and a large Palmgrass (Setaria palmifolia) infestation. Woolly nightshade and wattle also hang over the streambank here, and Madeira vine is visible climbing the lower outer branches of trees (presumably part of the Madeira infestation affecting Tanekaha https://inaturalist.nz/posts/23717-madeira-vine)
We will also be interested to see if we can reach the streamside on the bush trail side, where young wild mahoe, kanuka and tree ferns were present in 1997 right to the water's edge.This particular area is above "Inanga Pool" (the site of some 1997-99 streamwater sampling events), then sunlit from the Kaipatiki Roadside, pleasant and accessible, and regularly hand-weeded while enjoying the regeneration along the streamside
https://inaturalist.nz/observations/24650825
The current Kaipatiki Rd-side Elaeagnus invasion above Eleagnus Block/Inanga Pool is adjoined uphill by a large area of blackberry, similarly present and uncontrolled 1997-99 but, like the Elaeagnus, now hidden from the Native Plant Trail by streamside native vegetation, and from the roadside by planted canopy.
A group of observations of the Elaeagnus Block streamsides in 1999 and currently have been gathered here
https://inaturalist.nz/posts/24611-elaeagnus-block-a-massive-invasion-of-streamside-in-1997-with-current-extensive-regrowth
Elaeagnus in the upstream area generally
Regrowth from smaller, or more completely treated, invasions was similarly controlled manually along the upstream banks generally.
From early in 1999 the 7 days a week volunteer programme allowed its daily sitework to be largely diverted from weeding streambanks to assisting in the construction of the public "Native Plant Trail"
link to be added
and releasing the huge 1999 Arbor Day and subsequent roadside plantings from kikuyu, docks and Calystegia, throughout approximately 2km of roadside.- link to be added
Large Elaeagnus invasions border the bush path at several points of light-invasion due to prior tree falls, eg of ringbarked or felled wattles, on the bank below housing.
These invasions have some dead wood around them, suggesting they have been pruned to clear the path, but their continued spread along and up the bank is uncontrolled.
UPDATE: A curving Elaeagnus branch was close to being overhead of path users and also close alongside the path, so some of the dead branches beneath this huge bush was cut away, and a lot of live wood branches up to 4m long were then able to be reached and sawn off. They were cut into shorter lengths and piled on the opposite side of the path.
This half-hour operation released a ponga underneath, which had one live frond growing downwards under the weight of the Eleagnus, and a similarly suppressed branch of the pate tree alongside. Unfortunately some of the pate branch was broken during removal of the Eleagnus, which was as high overhead as we could reach and too heavy to move accurately. However the pate and the ponga both have a little room to grow, but will continue to be suppressed or destroyed by the Eleagnus unless it is controlled completely.
https://inaturalist.nz/observations/26166049
In the downstream area
Just above the tidal reach a large invasion can be seen on the Witheford Dr streamside under diverse native canopy:
https://inaturalist.nz/observations/16253701
New invasions
The fruit of mature Elaeagnus continues to ripen and be spread by birds
resulting in thousands of seedlings throughout the Reserve
https://inaturalist.nz/observations?verifiable=any&place_id=any&field:Elaeagnus%20reflexa=Seedling
some of which can be easily and completely uprooted with finger and thumb
Trial manual control of juveniles
Juveniles are common throughout the site in all plant communities observed and in all light and moisture conditions
https://inaturalist.nz/observations?verifiable=any&place_id=any&field:Elaeagnus%20reflexa=Juvenile%20uncontrolled
Some have been suppressed by leaf-stripping and twisting the flexible, thornless young shoots into a loop, with older branches and trunks being either cut, broken or partially broken, either in the course of this survey or in earlier informal survey.
On a seedling/juvenile with slender stems, usually 30-100cmH, the intervention described takes only takes a few seconds in passing and no tools, and slows them down considerably. A few larger juveniles with extensive branching and climbing into adjacent vegetation, and main stems to c.2cmD, have been suppressed similarly, by sawing part-way through trunk and main branches, then bending/ breaking downwards, avoiding leaving any stems in contact with the ground.
Some of those examples, and others not yet added to iNat, are being monitored to assess the speed of regrowth.
At least one small one (40-50cmH) earlier suppressed by this method had little or no regrowth and were easily uprooted during later survey. This was an ununsual finding, so soon after first intervention, and we attribute the ease of uprooting to weakening of roots through the intervention, combined with particular soil conditions and drought.
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