The Japan Hotspot Project - Week two: Chichibu Forest

This last week has been spent collecting and surveying in the University of Tokyo Chichibu Forest, Saitama Prefecture. This area falls within the Chichibu Geopark and comprises mixed deciduous and evergreen forests, mountains up to 2000m and some stunning scenery. During our stay the autumn colour was just developing, creating some magical hues.

Being further inland the forest is classified as temperate, containing a more familiar flora to that found in the warm-temperate coastal forests of the Boso Peninsular in Chiba Prefecture. A second typhoon prevented work on one day, but the remainder were jam packed; trekking through the forest collecting seed and conducting vegetation surveys.

Vegetation surveying

Collection highlights included Trochodendron aralioides, Tricyrtis hirta, Abies veitchii, Arisaema japonicum, Betula grossa and Hosta longipes. We also encountered Pteridophyllum racemosum, a monotypic endemic genus in the family Papaveraceace. Alas, we were 3-4 weeks too late for seed, so hopefully we will see it again on further trips. Fortunately the fauna was much tamer here, no sight of snakes, giant spiders or macaques.

Pteridophyllum racemosum

Our last day in the forest involved a one hour ascent aboard a (very small and precarious-looking) monorail. A great way to see the vegetation and a very unique experience indeed.

All aboard!

We are now in Tsukuba, north of Tokyo, for a few days working on the species rich Mt. Tsukuba. We head to Toyama for our final week of fieldwork on Thursday.

Week one collecting & surveying on the Boso Peninsula

After a slight delay due to the super typhoon whilst in Tokyo, we made it to the University of Tokyo Forest, Chiba. Despite losing a couple of days in the field, we have managed to make some good collections and complete two rapid botanic surveys; one on Mt. Sengen and the other in Godai forest. Some of the highlights from the collecting and surveying were Tricyrtis hirta, Dendropanax trifidus, Cardiandra alternifolia, Torreya nucifera, and Castanopsis sieboldii.

Tricyrtis hirta

In and amongst the collecting, we have also encountered a wide variety of wildlife; Wild boar, Macaques, deer, big spiders and infinite leeches. We have also been lucky enough to see (from a safe distance) a Tiger Keelback snake….

Tiger Keelback snake...

Hisamoto-san (Research Associate UTF Chiba Forest) & Dan Luscombe, Curator, The National Pinetum, Bedgebury 

Cut test to establish seed viability

Eupetelea polyandra voucher 

Today has been spent making a few last collections, with the main part of the day sorting herbarium vouchers, cleaning seed and labelling images. Everything needs to be packed up and loaded into our (not as big as we were hoping) car!! Tomorrow we leave the Boso peninsula and have a five hour drive, heading back up past Tokyo and onto Chichibu. 

The Japan Hotspot

We have arrived in Japan for the second of our seed collection trips as part of the Japan Hotspot Project. Over the course of the next four weeks we will travel across central Honshu, visiting the University of Tokyo Forests of Chiba and Chichibu, Mount Tsukuba in Ibaraki Prefecture and finally collection sites in Toyama Prefecture.

Once again we shall be conducting Rapid Botanical Surveys to support ongoing Biodiversity Hotspot research at the Department of Plant Sciences Oxford, collecting seed for ex situ conservation in collaboration with partners in both Japan and the UK and collecting supporting herbarium vouchers to be accessioned into the University of Oxford Herbaria.

We will update the blog each week, but you can also follow our progress on Facebook or via Twitter.

Tom Price (Gardens Curator) & Ben Jones (Arboretum Curator).

An update of changes and developments at the Harcourt Arboretum

This month at the Arboretum we have made some quite substantial changes, in particular the Tree Team have been focusing on an area previously known as the Bamboo glade. Over the years this area has lost a number of specimens, due to frost damage in harsh winters. This had created an opportunity to change and develop the focus of this area along with an adjacent space, which has predominantly been self-seeded Sycamore (Acer pseudoplatanus) and Birch (Betula spp). Over the previous weeks the Arborists have been working to remove a selection of these species in order to open up the area for future planting space.

 In addition to this, views of current and interesting specimens have been opened up. There is now a spot from which the full height of one of the Giant Redwoods (Sequoiadendron giganteum) can be appreciated, alongside the largest Dawn redwood (Metasequoia glyptostroboides) at the arboretum. In this process a young but important Coast Redwood (Sequoia sempervirens) is soon to be exposed, also.

Luke Rowland dismantling one of the Sycamores

Timber extraction

In the process of opening up the new space, a significant amount of stumps have been created, which on arrival of the new stump grinder will be targeted with vigour. The removal of these stumps will open up a large area of ground space, allowing ground preparation to be carried out, and finally to be planted with new species which are currently waiting in the nursery.

Guy Horwood and Luke Rowland

Anyone for a cuppa?

A bud about to burst open

Cobaea scandens is a vigorous climber from the tropical forests of Mexico. It climbs using hooked tendrils which spin round in spiral movements to grip onto supports. In its natural environment it grows as a perennial, but in the temperate zone it is usually grown as an annual, where it will put on a lot of growth in a short period of time, and flower at the end of the summer.

Each flower is borne singly, on outstretched stems, held above the foliage. They start out as a green, flanged, pod-like calyx which slowly opens up to reveal the closed petals which resemble an egg, and are whitish green. Once the flower has opened it starts to look more bell-shaped, and with the calyx sitting underneath the bell, it looks like a cup and saucer, which is the common name for this plant. As the flower matures it gradually changes colour from white to dark purple, although it retains some white stripes which radiate out from the centre.

A creamy white, newly opened flower

Protruding from the back of the petals there are five stamens, each carrying a pair of pollen parcels, or anthers at their tips. These parcels need to open up to release the pollen that they hold, and once this has happened the anthers are pushed forwards and held up ready for a pollinator. The pollinator of choice for a Cobaea scandens is a bat. This is significant because it explains some the flowers' morphology, and why they open their petals during the night. The size and shape of the flower is perfect for a small nectar-eating bat to sup from, while brushing its belly against the stamens to extract the pollen, and then to deposit it neatly onto the style of another flower.

The flower begins to turn purple

One of the major advantages of bat pollination is that pollen can be transported across further distances, and in significant quantities, providing plants with a bigger genetic neighbourhood, while reducing genetic subdivision between populations. Another reason why bats are good pollinators is that they carry pollen from several different potential fathers to the same stigma, which increases the genetic variability of the population.

A mature flower

Virginia Vargo, Trainee Botanical Horticulturist.