For many years the students on the Comparative and Adaptive Biology field course in Mallorca have visited the strandline and salt marsh plant communities at the Albufereta Nature Reserve on the Bay of Pollença. This year, however, we went for a tour of the S’Albufera wetland (a Ramsar protected site of international importance) by Gaspar, one of the team who manages the reserve. The reserve has been protected since 1988 and is surrounded by the coastal tourist resorts and inland agricultural lands.
The land around the Bay of Alcudia is naturally marshy, with water from the seasonal rivers (torrents) held back by the sand bars at the coast. However, the marsh isn’t entirely fresh, but is brackish and salty in places as seawater infiltrates the sand to saturate the land behind. This winter was drier than average, leading to the marsh being saltier than usual for so early in the year. In the 19th century, the British civil engineer John Frederick Bateman carried out work to drain the marsh for agriculture, creating the infrastructure which is still visible today – a network of canals, ditches, bridges and old pumping houses. More recently the focus has been on retaining the water and so sluice gates have been added to maintain the wetland habitat for wildfowl. The reserve is a carefully managed mosaic of old reedbeds (dominated by Phragmites australis), open waters, scrapes and salt marsh. Horses are particularly important for managing the more open environments, keeping the reeds in check.
The human population around the reserve around 60,000, but over the summer season this can triple with the arrival of holidaymakers seeking some Mediterranean sun. This places a huge increase in demand for drinking water and wastewater treatment over the driest months in the Mediterranean. It is at these times when the reserve is at its most vulnerable from pollution (e.g. nitrates escaping from water treatment works) without the potential for a diluting influx of freshwater.
The wetland is used by some bird species all year round and by others who use it as a staging post on their migrations. With the background soundtrack provided by Cetti’s warblers, we watched black-winged stilts, avocets, egrets, a kingfisher, shelducks, crested coots and an osprey. Still, the zoological highlight happened later in the day as the flamingos treated us to a fly-by on the beach.
There’s still time for one final post before it’s time to say goodbye to the Mallorca field course for another year. With two orchid fans on the staff, it’s not surprising that a good few hours each day were spent orchid spotting, but this year we had an up-and-coming orchid specialist amongst the students too. Head over to the FrogBlog to check out Tom’s thoughtful account of his Mallorcan orchid-hunting experiences.
The Passo Pura in the Carnic Alps was awash with summer flowers when we visited for our Field Course in Alpine Biodiversity and Forest Ecology in July. One interesting walk took us up this seasonal stream bed on the side of Monte Tinisi and rewarded us with some beautiful Lady’s Slipper Orchids (Cypripedium calceolus).
The flowers in the hot Italian sun were fading and drying up, but the plants in the shade were perfect.
I’d only ever seen this plant in cultivation before, so it was a treat to see it growing wild. In the UK it is very rare having been lost from many sites through 19th century collecting for the horticultural trade. The lady’s slipper orchid was thought extinct in the UK until a plant was found growing at one site in Yorkshire. This plant has been the focus for conservation and re-introduction programmes.
We also have pressed examples of this species in the herbarium collection and one sheet is on display in the Living Worlds gallery. This example was collected in the same area of the Carnic Alps in 1897 by James Cosmo Melville. He didn’t do a very good job of pressing the intricate 3D flowers, which is one reason why orchid flowers are often preserved in spirit collections.
This specimen collected from neighbouring Austria does a much better job of showing the structure of the flowers. However, the person who picked it also included the roots (not just examples of the leaves and flowers) which could have had consequences for the population of plants at that site. Like other orchids, germination needs the presence of a symbiotic fungus and the lady’s slipper orchid can take many years before it reaches flowering size.
I’ve spent the last two weeks on a field course with 25 undergraduates from the Faculty of Life Sciences studying Alpine Biodiversity and Forest Ecology. We stayed at the wonderful Rifugio Tita Piaz in Passo Pura in the Carnic Alps and made use of the facilities at the field centre of Baita Torino.
We were really lucky to have Professor Nimis, Professor of Systematic Botany at The University of Trieste and renowned lichenologist, come to talk to us at the beginning of our stay. He explained how the biodiversity of the area arose after the last ice age. Some plant species survived in patches where the mountains rose high enough above the local glaciers to provide a refuge for life (known as nunataks). Others arrived after the ice melted, migrating into the region from the Baltic, Siberia or Southern Italy.
Prof Nimis also introduced us to his excellent key to the flora of this region. Produced as part of the Dryades project from the University of Trieste, it is now available translated into English, either online or as an Apple app. This was a great tool for students to use for their project work investigating aspects of the environment around them.
The University of Manchester has broken up for the Easter holidays and so it must be the right time of year again for the 1st year field course in Comparative and Adaptive Biology. This year the staff and students were even more enthusiastic than usual to escape the unseasonably cold snow flurries of Manchester and head for sunny Mallorca. We’ve been braving the mosquitoes in the shrubberies to study how plants cope with the challenges of Mediterranean living and to see some interesting examples of plant endemism.
Last year I blogged about one of our days on the seashore, so I think this time I shall go more terrestrial and share some images from a site which is one of the staff favourites. Although there are other places to go and see Holm Oak (Quercus ilex) woodland, the Bronze Age talayotic site of Ses Paisses is pretty special. Excavated in the mid 20th century, the settlement is arranged around a central tower (or talaiot) and is now covered by a very nice woodland.
Under the shade of the oak trees we find black bryony (Tamus communis), butcher’s broom (Ruscus aculeatus) and a hemi-parasitic plant Osyris alba which can produce it’s own sugars by photosynthesis but steals water and minerals from a host plant .
However, with all these rocks around there is always the chance that botanical lectures on the effects of light and shade can end up being disrupted by sudden acts of zoology….
Now there couldn’t be a finer way to listen to a lecture! These first-year undergraduate students from the University of Manchester are in Mallorca to learn about Mediterranean ecosystems and plant adaptations to the climate. On days like today it’s much easier to explain the challenges of the Mediterranean climate than on days when the rain is falling steadily. They also get to appreciate the view too; this view is out across the Bay of Pollensa where underneath the water there are large beds of seagrass called Posidonia oceanica or Neptune’s grass.
Although underneath the waves, it not a seaweed and is actually a flowering plant. It can produce fruits which float on the ocean, but it also spreads very slowly by creeping rhizomes. A recent study published in the journal Plos One has shown that these clonal meadows of seagrass could be thousands of years old.
Growing at depths of about 1-45m (depending on water clarity) these seagrass beds are very important ecosystems. These meadows trap carbon dioxide and release oxygen in coastal waters through photosynthesis, provide energy at the bottom of the food chain and act as nursery grounds for many fish and invertebrates. The environmental importance of this ecosystem is reflected by its protection as a priority habitat by the legislation of the EU Habitat Directive and by the programs aimed at conserving it.
These meadows also have important effects on the seashore. Debris is washed-up from below the sea and collects on the beaches, sometimes forming great sculpted ‘cliffs’ of plant material. These heaps of dead seagrass leaves and rhizomes are striking, but far more curious are the fibre balls which can also be found on some beaches. Wave action on the beach smashes up and wears away the tissue of the seagrass leaves, leaving only the leaf veins which get tangled up and moulded into these pebble shapes.
Which ever form the material ends up on the beach in, once there it helps to stabilize the shifting sands to build dunes, to retain water and to provide nutrients which allows plants to colonize the strandline. Plants such as this lovely yellow-horned poppy (Glaucium flavum) which sadly isn’t in flower yet.
Best go back to staring a that sunny view………..