Successful species (1/8/2008)

Quentin Groom has analysed the Maps Scheme database to find out which species are increasing fastest since 2000. The top 100 are listed below. These include some ‘invasive’ aliens and some previously under-recorded taxa such as Sorbus hibernica, where the efforts of Tim Rich and David Cann have revealed many more plants than were previously known. Recorders are also seemingly paying more attention to garden escapes, crop volunteers and forestry trees. One or two of them are rare ‘natives’, however, that seem to be doing rather well. Here are the plants to look out for...

Acer saccharinum, Alchemilla mollis, Allium cepa, Allium subhirsutum, Alnus cordata, Alyssum saxatile, Amaranthus hybridus, Ambrosia artemisiifolia, Bassia scoparia, Berberis thunbergii, Bergenia crassifolia, Bromus secalinus, Buddleja globosa, Campanula poscharskyana, Cardamine corymbosa, Chamaecyparis pisifera, Chenopodium glaucum, Chenopodium quinoa, Cochlearia danica, Conyza bilbaoana, Conyza sumatrensis, Cordyline australis, Cornus alba, Cortaderia richardii, Cotoneaster rehderi, Crocosmia pottsii, Crocus chrysanthus, Crocus tommasinianus, Crocus vernus, Cyclamen coum, Cyclamen hederifolium, Cymbalaria pallida, Cyperus eragrostis, Echinochloa crus-galli, Echium pininana, Echium plantagineum, Erigeron glaucus, Erigeron karvinskianus, Euphorbia characias, Fraxinus ornus, Fumaria purpurea, Galanthus elwesii, Galanthus ikariae, Galanthus plicatus, Geranium macrorrhizum, Griselinia littoralis, Guizotia abyssinica, Hedera colchica, Helianthus annuus, Helleborus argutifolius, Heuchera sanguinea, Hyacinthus orientalis, Hydrangea macrophylla, Hydrocotyle ranunculoides, Iberis sempervirens, Illecebrum verticillatum, Iris orientalis, Kerria japonica, Kniphofia praecox, Linaria maroccana, Lobelia erinus, Lonicera pileata, Mentha pulegium, Narcissus aggregate, Nicandra physalodes, Nigella damascena, Oxalis exilis, Paeonia officinalis, Persicaria capitata, Phacelia tanacetifolia, Phalaris paradoxa, Philadelphus x virginalis, Photinia davidiana, Physalis peruviana, Phyteuma orbiculare, Pinus contorta, Poa infirma, Polygonum boreale, Polypogon viridis, Pontederia cordata, Populus 'Balsam Spire', Populus nigra 'Plantierensis', Pyracantha coccinea, Rhus typhina, Rosmarinus officinalis, Saxifraga spathularis, Scilla bifolia, Scilla siberica, Sedum spectabile, Senecio inaequidens, Sisyrinchium striatum, Sorbus croceocarpa, Sorbus hibernica, Stachys byzantina, Symphytum 'Hidcote Blue', Tellima grandiflora, Tristagma uniflorum, Verbena bonariensis, Veronica crista-galli, Zea mays.

Draft Fumitory Maps (5/7/2008)

For the forthcoming Fumitory Handbook I would like to appeal to recorders to check the distribution maps. This is something new we can do using electronic mailing – consulting with the county recorders about the distribution maps before printing a book or atlas. The main reason for not doing this before, of course, has been the impracticality of sending lots of paper maps to lots of people.

As an experiment, I am posting draft maps of the main fumitories here. Please check to see that there aren’t any silly dots in the vicinity of your vice county, or any well-known sites missing.

Please note that we’re using a new type of map. Old records are shown as progressively smaller dots, which serves to downplay the importance of the occasional rare casual, which is quite a big element in the fumitory maps, and instead highlight the natural distribution pattern of the species.

What is Bocage? (27/6/08)

Bocage is a landscape of narrow, winding lanes, tall hedges and small copses that characterises some parts of western Europe, including Normandy. In May this year Natural England wanted to search for bocage-type habitat in south-western England in order to target agricultural subsidies, and they asked the BSBI to provide distribution data at tetrad scale to produce coincidence maps.

The species they chose were Agrimonia procera, Astragalus glycyphyllos, Epipactis atrorubens, Fallopia dumetorum, Fumaria capreolata, Geranium sanguineum, Lithospermum officinale, Luzula forsteri, Melittis mellisophyllum, Ornithogalum pyrenaicum, Orobanche purpurea, O. rapum-genistae, O. reticulata, O. caryophyllacea, Phyteuma spicatum, Pyrus cordata, Rosa canina x stylosa, R. micrantha, R. stylosa, R. tomentosa, Sorbus devoniensis, S. torminalis, Stellaria neglecta, Vicia bithynica, V. parviflora, and V. sylvatica.

This is the great advantage of tetrad scale mapping. Compared with the 10km data, which shows the range of each species, the tetrad maps give a much better view of the distribution. We need to keep gathering data at tetrad scale or better. The map here shows Stellaria neglecta at 2km scale – much more interesting than at the normal 10km scale, even though some counties haven’t yet recorded it at this level of detail.

What exactly is this distribution pattern, though? Neither westerly nor easterly - it most likes the Welsh Marches and a line down the middle of the British Isles. There are several other species that have this curious distribution, including Fumaria purpurea and Chrysosplenium alternifolium. Can anyone come up with an explanation?

Axiophytes (1/6/08)

Several new axiophyte lists have been uploaded to the web site recently, including ones for Hampshire, Berkshire and Staffordshire. Some recorders have asked if they can edit their existing axiophyte lists, and the answer, of course, is yes. It is interesting to see which species others have chosen, and I suspect that it takes a few years of using them to really get the lists refined.

Dan Wrench has pointed out that rule 3 for the selection of axiophytes is unnecessary, and perhaps wrong. This is the rule that excludes rarities with fewer than 3 sites. The reason for this was that, traditionally, people tended to confuse rarity and conservation value, so all rare species were automatically considered important. However, some rarities – perhaps most – are virtually irrelevant to nature conservation. A good example of this would be Leersia oryzoides, perhaps – a rare (and possibly non-native) plant that happens to occur in one nice site but is more of a casual than an indicator species (debate!). However, some rare species are rare because they have declined, and are therefore strong axiophytes. So perhaps rule 3 needs to be modified, to say something like ‘leave out rarities unless you are sure they are highly specific to good habitats, rather than just happen to be in a good site.’

Visit the axiophytes page for more information.

Drosera x obovata request (1/6/08)

We had this request in May...

Hello, my name is Rosineide Souza-Richards and I am conducting a research project as part of my dissertation topic for the MSc in Plant Diversity on three species of Drosera native to the British Isles. They are widespread but are believed to have been declining through habitat degradation and loss. The natural hybrid of Drosera anglica Huds. and Drosera rotundifolia L., Drosera x obovata Mert. & W.D.J. Koch, is found throughout suitable habitats in the British Isles (Preston et al. 2002) but is never common. The hybrid appears fully sterile but can reproduce vegetatively.

In this project I aim to gather more information on the hybrid to achieve the following aims:

• To establish the direction of hybridization in naturally occurring specimens of D. x obovata
• To produce updated distribution maps of this species throughout the British Isles through examination of herbarium material and web-based data gathering to establish past and current patterns of distribution.
• To establish whether this hybrid has shown a change in distribution and frequency over time.
• To study the autecology of D. x obovata to better understand its pattern of occurrence in relation to habitat and distribution of the parental species.

How can you contribute?

If you manage to find a population of D. x obovata, please let me know because I am interested in tracking down its patterns of distribution across the British Isles to establish if there have been any changes over time.

If you have known sites for the plant for several years any eye-witness account of the stability of the population would be helpful. I would be very pleased to receive any records or possible sites (or specimens for identification).

If you have permission to collect material, then two or three leaves from one plant, dried rapidly between sheets of kitchen towel and accompanied by a digital image of the plant, would provide enough for my DNA work and to confirm the identity of the material.

I can be contacted by email at the University of Reading - r.souzarichards@reading.ac.uk.

All contributions to the project will be appropriately acknowledged in resulting publications.

For more information on my project, please check my webpage

http://www.biosci.reading.ac.uk/Teaching/MScPlantDiversity/MscPlDivProject.htm.

Thank you very much for your support.

Alien Invaders (Jan 2007)

The BSBI generally takes the view that invasive alien plants are less of a problem in this country than might be imagined. Here’s our discussion paper on the subject.