Earlier this year, the Wellington branch of Forest & Bird held a bioblitz in a local reserve they are helping to restore. Curator Botany Leon Perrie talks about looking for the little plants.
Bioblitzes are a short, concerted effort by a community to record as much as possible of the biodiversity present in an area. Forest & Bird’s Wellington Branch wanted to know what was living in Chartwell Reserve.
The Chartwell Reserve bioblitz
Chartwell Reserve lies to the north of Ōtari-Wilton’s Bush, on the boundary of the Wellington suburbs of Wilton and Crofton Downs. Hillside regenerating forest surrounds a basin of damp grassland.
Over its seven days, the bioblitz recorded over 500 species of plants, animals, fungi, and other lifeforms in the Chartwell Reserve. Most are indigenous species. That’s impressive diversity for a small area of what might seem an unprepossessing young forest on Wellington’s fringe. It’s an example of how even our cities can be home to large numbers of species, and that we should be mindful of how we interact with them.
You can read the Chartwell Reserve Bioblitz summary on the iNaturalist website.
I participated in the bioblitz for a couple of days and was joined by Te Papa Geneticist Lara Shepherd. Lara individually recorded over 190 species! Among the notable species we encountered were a native orchid, a native fern, and a weedy sedge.
Mosses and liverworts
While I kept half an eye on the bigger plants, I was mostly looking for mosses and liverworts. These small plants are often overlooked, but their small size belies their significance. Over 1,100 moss and liverwort species are indigenous to Aotearoa New Zealand, which is nearly a third of our native species of land plants. They can collectively comprise a significant portion of ecosystem biomass, particularly in wetter areas, and can be important in nutrient and water cycling, and in colonising fresh ground.
Te Aka Māori Dictionary website gives “pūkohukohu” as one of the words for moss. Other meanings for pūkohukohu are lung, and to be spongy or misty, which are physically and ecologically resonant with mosses – and liverworts.
Bryophytes is the English collective word for mosses and liverworts, as well as hornworts. Unlike the other groups of land plants (ferns, lycophytes, and seed plants), bryophytes generally lack specialised vascular cells for internal transport of water and nutrients; hence, their small size.
Mosses generally produce their spores for dispersal in capsules held erect on long-lived, wiry stalks. Usually, the spores are released through a circular opening. Moss leaves are generally triangular or oval, and often have a mid-vein.
In liverworts, the stalks of the spore capsules are generally white, fleshy, and short-lived, and the spherical capsule splits into four valves to release the spores. Some liverworts produce a non-leafy body known as a “thallus”, with plates or ribbons of tissue. But most are leafy. Liverwort leaves can be very intricate with various appendages, but they do not have mid-veins.
Hornworts always have a non-leafy thallus. The spores of hornworts are made in erect horn-like structures that spiral open.
The pūkohukohu of Chartwell Reserve
Thirty-seven species of mosses, 24 liverworts, and 1 hornwort were found during the bioblitz. That is more than 10% of the total biodiversity that was recorded. I still have a few identifications to finish, so these numbers will likely increase slightly. My thanks to those who helped with the searching and identification, especially Lara Shepherd, Paul Bell-Butler, and Kate Jordan.
Many of the bigger, more obvious New Zealand bryophytes seem absent from Chartwell Reserve. This could be because of the young age of the forest. Many of the species we found were small, and often closely appressed to rocks, soil banks, or tree trunks. A hand-lens with ×10 magnification is generally an essential tool for looking at bryophytes in the field, and even more so in Chartwell. Many identifications also need checking under a microscope, which can be fiddly and slow (and partly explains why I haven’t finished all of the identifications).
Below are some of the mosses and liverworts seen in Chartwell Reserve.
If you look closely, you will find mosses and liverworts all around you, including in town, such as on rock walls, tree trunks, between pavers, and among grass.
Learning how to distinguish pūkohukohu can be tricky, but a good start can be made by using a hand-lens or strong magnifying glass to examine the shapes of their leaves and, if present, spore-making capsules. If you can upload close-up photos to the iNaturalist website, it is possible that the community there will be able to help make identifications.
