Achievements in Weed Control on The Pinnacle Nature Reserve
This page provides links to reports that describe a range of achievements in fotpin's weed control program. For the most part, the reports document our progress in controlling particular weed types. Other reports summarise particular weed control efforts, such as our effort in the Pinnacle Extension offset area prior to it being incorporated into the Reserve.
Progress in controlling Blackberries (updated July 2023)
Persistent mapping, treatment and follow-up of occurrences of blackberry (Rubus anglocandicans) resulted in their virtual elimination from the Reserve and contraction of their prevalence towards the William Hovell Drive boundary of the controlled area up to 2020. Unfortunately the favourable growing conditions between 2020 and 2023 have seen a resurgence in numbers, especially in the 2022-23 season. Their increased prevalence is seen across the Reserve but is particularly noticeable in the Kama Link paddock (the 2016 Offset addition to the Reserve). This is likely connected to the proximity of that area to William Hovell Drive where blackberries are rampant along the verge and untreated by City Services until autumn 2023, thus providing a rich source of re-infestation.
Assessing the impact of 12 years of spraying Sweet Briar (updated July 2023)
A summary of indicators are presented to show that fotpin is successfully reducing the number of briars (Sweet Briar, Rosa rubignosa) on the Pinnacle Nature Reserve from 44 briars/hectare in 2011 to 3 per hectare in 2023.
Indicators include: the decline in the number of briars requiring treatment each season, the decline in the density of briars overall as well as at specific hotspots, and the decline in the amount of time and chemical spent controlling briars.
Measuring success in controlling Verbascum (updated January 2023)
One of fotpin's target weeds for many years has been Verbascum, both V. thapsus (great mullein) and V. virgatum (twiggy mullein). Since 2011 one of several heavily infested areas (see Visual progress with Verbascum control) has been sprayed systematically and regularly and the amount of spray required each time recorded. The recorded decrease and then sudden increase in the amount of spray needed on that area each year allowed the deduction that the amount of Verbascum each season, as indicated by the amount of spray required, was strongly correlated with summer rainfall. This relationship was subsequently shown to apply across the whole Reserve.
Successive negative deviations from this observed relationship following near-record rainfall years may indicate temporary success in controlling Verbascum.
One of fotpin's target weeds for many years has been Verbascum, both V. thapsus (great mullein) and V. virgatum (twiggy mullein). One of several heavily infested areas was photographed in 2007. Since 2011 this area has been sprayed systematically and since 2014 follow-up photos have been taken. The contrast between the pre- and post- spraying photographs is stark.
Weed control history in the Pinnacle Extension offset area (2011 to 2016)
In October 2014, approval was given for an extension to the Pinnacle Nature Reserve by including an area identified for an environmental offset. Friends of the Pinnacle has been carrying out weed control for at least 5 years in the area that is now the offset. Since July 2011, records have been kept both of effort (time spent) and exactly where that effort was (using GPS tracks and waypoints).
St. John's Wort Spraying: 2011-12 and 2012-13 Seasons (May 2013)
The effort for the 2012-13 spraying season is shown here for each of our “paddocks” or management units (see map on next page), and
compared with effort in previous years.
