Cneoraceae

Abstract: Aim In this study we tested the hypothesis that the dispersal success (estimated here as fruit removal rate) of a native shrub species living in the Balearic Archipelago, Cneorum tricoccon L. (Cneoraceae), has decreased significantly in those islands where endemic lizards of the genus Podarcis have disappeared. These lizards acted as the main seed dispersers of the plant and became extinct after the introduction of carnivores. At least one of these carnivores, the pine marten (Martes martes L.), is also an important frugivore, consuming the fruits and dispersing the seeds of C. tricoccon and thus allowing the comparison of fruit removal rates between the two groups of vertebrates (lizards and mammals). We further tested the possibility that lizards (in particular, P. pityusensis Bosca `) could be exerting selection on seed size. Methods In seven populations from four islands, we monitored fruit removal by either lizards or mammals. The fruits of C. tricoccon do not drop after ripening, remaining attached to the branches for long periods if not removed. In order to test whether lizards might be exerting selection on seed size, we compared seed diameter and weight between defecated and uningested (collected directly from plants) seeds for each of the populations. Results Fruits were removed in significantly greater proportions in those populations where lizards are still present. Data showed that in two of the examined populations in the Pityusic islands, defecated seeds were lighter and smaller than controls suggesting that lizards selected fruits of smaller size than the average of the population. Main conclusions The introduction of carnivores in the Balearics has led to important changes in the population dynamics of many native species. In the larger islands (Mallorca and Menorca), carnivores seemed to have caused the extinction of endemic lizards who acted as the only dispersers of some plants such as C. tricoccon. Pine martens, in particular, are in turn frugivorous and thus can ‘replace’ to some extent the ‘lost’ seed dispersers. We hypothesize that besides having decreased fruit removal rates in this shrub, these ‘new’ dispersers have modified considerably the distribution of the plant on Mallorca island, as the fossil record shows that lizards lived at low altitudes (<500 m a.s.l.) and the plant can be currently found up to 1000 m a.s.l. Furthermore, preliminary data suggest that lizards might be exerting a selective pressure on seed size. If this is true, this pressure might have been released – or counteracted if carnivores select for fruit size as well – after the extinction of lizards from some islands, which would have important ecological consequences for the plant.

Abstract: Plants can respond to climate change by either migrating, adapting to the new conditions or going extinct. Relict plant species of limited distribution can be especially vulnerable as they are usually composed of small and isolated populations, which may reduce their ability to cope with rapidly changing environmental conditions. The aim of this study was to assess the vulnerability of Cneorum tricoccon L. (Cneoraceae), a Mediterranean relict shrub of limited distribution, to a future drier climate. We evaluated population differentiation in functional traits related to drought tolerance across seven representative populations of the species' range. We measured morphological and physiological traits in both the field and the greenhouse under three water availability levels. Large phenotypic differences among populations were found under field conditions. All populations responded plastically to simulated drought, but they differed in mean trait values as well as in the slope of the phenotypic response. Particularly, dry-edge populations exhibited multiple functional traits that favored drought tolerance, such as more sclerophyllous leaves, strong stomatal control but high photosynthetic rates, which increases water use efficiency (iWUE), and an enhanced ability to accumulate sugars as osmolytes. Although drought decreased RGR in all populations, this reduction was smaller for populations from the dry edge. Our results suggest that dry-edge populations of this relict species are well adapted to drought, which could potentially mitigate the species' extinction risk under drier scenarios. Dry-edge populations not only have a great conservation value but can also change expectations from current species' distribution models.

Abstract: The following chromosome numbers are reported: Miersia chilensis 2n = 20, Gethyurn atropurpureum 2n = 14 (Alliaceae); Aextoxicon punctatum 2n - 32 (Aextoxicaceae); Nymania capensis 2n = ca. 48 (Aitoniaceae); hlex pedunculosa 2n = 120 (Aquifoliaceae); Oroxylon indicum 2n = 38, Millingtonia hortensis 2n = 30 (Bignoniaceae); Canella alba 2n = 28 (Canellaceae); Cneorum tricoccum 2n = 36 (Cneoraceae); Eucryphia lucida 2n = 30 (Eucryphiaceae); Greyia sutherlandii 2n = 32-34, n - ca. 17 (Greyiaceae); Koeberlinia spinosa 2n =ca. 88 (Koeberliniaceae); Erythrina burttii 2n -ca. 168 (Leguminosae); Rhynchocalyx lawsonioides 2n = 20 (Lythraceae); Montinia carylophyllacea n - 34, 2n = 68 (Montiniaceae); Olinia emarginata 2n = ca. 40(-42), 0. radiata ii = ca. 30(-28) (Oliniaceae); Oftia africana 2n = 38, n - ca. 19 (Scrophulariaceae). A survey of cytology and evolution in the Angiosperms by Raven (1975) has brought to attention many examples of groups that are unknown cytologically. Numerous gaps exist both at the family level and amongst phylogenetically critical subfamilies and genera. The present paper, in which the cytology of several rare or critical taxa is reported, represents a contribution to our knowledge of some of these groups. Of the 22 collections, representing 18 taxa studied here, 11 are believed to be the first reports for the following families: Montiniaceae and Oliniaceae, and if the following are recognized, Aextoxicaceae, Aitoniaceae, Eucryphiaceae, Greyiaceae, Koeberliniaceae and Oftiaceae. In addition to the genera in these families (Montinia, Olinia, Aextoxicon, Nymania, Eucryphia, Gre yia, Koeberlinia, and Oftia), the present report also includes first records for the following genera: Canella (Canellaceae), Gethynin (Alliaceae), and Rhtynchocalyx (Lythraceae). Previous reports for Cneorurm (Cneoraceae), Oroxylon, and Millingtonia (Bignoniaceae) are substantiated while high polyploidy in species of hlex (Aquifoliaceae) and Erythrina (Leguminosae) is confirmed.