Jacques Bardat

Soil seed bank composition and diversity in a managed temperate deciduous forest

Little is known about the influence of forest management on the interaction between seed bank and aboveground vegetation. We surveyed seed banks and vegetation in 10 forest stands under similar abiotic conditions but submitted either to a coppice-with-standards treatment (n = 5) or to a selective-cutting system (n = 5). We analyzed species composition and diversity, community ecological profile, and distribution of taxa among different life forms, strategy, morphology and functional type categories. A total of 2085 seedlings (8296 seeds m−2) germinated-corresponding to 28 species, among which Juncus effusus was the most abundant. Fifty-seven percent of the species were also recorded in the aboveground vegetation, the dominant species being Rubus fruticosus agg., but only 28% of the aboveground species were present in the seed bank. Our results suggest that (1) vernal geophytes and shade-tolerant perennials, which group most true forest species, are not incorporated in the seed bank, (2) parent plants of most seeds were present either in the stand in an earlier dynamic stage or apart from the stand and long-distance dispersed, (3) as expected, early-successional species are well represented in the seed bank, (4) forestry vehicles seem to be a major means of dispersion for stress-tolerant species normally found in forest lanes and wheel tracks. We conclude that seed banks contain species that have a potentially negative impact on the true forest flora and, thus, forest management should minimize soil disturbance and retain remnants of old-coppice woods to conserve disturbance-sensitive true forest species.

Opposite responses of vascular plant and moss communities to changes in humus form, as expressed by the Humus Index

Abstract Question: Does the distribution of plant species found in forests correlate with variation in the Humus Index (based on a ranking of humus forms) and, if so, do the species exhibit different responses according to phyletic lineages? Location: Paris Basin, France, with a temperate Atlantic climate Methods: Mosses and vascular plants (herbs, ferns) were inventoried in two broad-leaved forests with contrasting soil conditions, where 15 and 16 sites were investigated, respectively. Variety of stand age and prevailing soil conditions were analysed in 5 plots and 20 subplots in a grid at each site. Mantel tests were used to estimate correlations between the Humus Index and plant species richness, taking into account spatial autocorrelation. Results: The local (plot, subplot) species richness of moss communities increased with the Humus Index, i.e. when humus forms shifted from mull to moder. The reverse phenomenon was observed in vascular communities. The opposite response of these two plant groups could be explained by opposite strategies for nutrient capture which developed in the course of their evolutionary history. Conclusions: Although not necessarily causative, the Humus Index predict fairly well changes in species richness which occur in forest vegetation, provided that phyletic lineages and geographical position are taken into consideration. Nomenclature: Rameau et al. (1989); Hill et al. (2006); Lambinon et al. (1999).

Checklist of the Bryophytes of Madagascar

Abstract This updated checklist of the bryophytes of Madagascar was compiled from the literature, herbarium and recent collections. A total of 1144 species and infraspecific taxa are recorded for Madagascar composed of 751 mosses, 390 liverworts and 3 hornworts. 28.67% of the species reported for the Island are endemics. Twenty-four taxa are newly recorded for Madagascar and two of them, Fissidens cyathaeicola Brugg.Nann. and Taxithelium nepalense (Schwägr.) Broth. are reported for the first time for the Sub-Saharan Africa region.

Additions to the bryoflora of Reunion Island 3: new and interesting records from the Tropical Bryology Group (British Bryological Society)

Abstract This contribution is a result of collaborative work based on the fieldwork organized during a workshop of the Tropical Bryology Group on Mascarene bryophytes in September 2008, and also from previous unpublished records of the authors. We add 35 new taxon records (17 mosses and 18 liverworts) as well as five other interesting records for Réunion Island (Mascarene Archipelago). Grimmia austrofunalis Müll. Hal., Sphagnum magellanicum Brid. subsp. magellanicum, Didymodon tectorum (Müll. Hal.) K. Saito, Anastrophyllum revolutum Steph. and Lejeunea exilis (Reinw. et al.) Grolle are reported for the first time for Africa. Syrrhopodon vardei L. T. Ellis, Ceratolejeunea papuliflora Steph. and Xylolejeunea grolleana (Pócs) X.-L. He & Grolle, previously known as endemic from Madagascar, are here recorded for Réunion. The latter species is also illustrated with SEM pictures.

Studies on African Riccardia Types and Related Material

Abstract The genus Riccardia, Aneuraceae is often considered as puzzling by bryologists, because of its great polymorphism, and African species have not been studied as a whole for several years. A type revision of the African species assigned to Riccardia is presented in order to get a clear view of the historical background before examination of recent material. Among the type material, two new citations are reported for Africa: Riccardia inconspicua (Steph.) Reeb et Bardat belonging to the subgenus Thornoneura and Lobatiriccardia cf. coronopus (De Not.) Furuki belonging to the closed genus Lobatiriccardia, not known before for Africa. Some synonyms have been corrected. The major taxonomical decisions will only be presented with the future revision of the African genus, after complete examination of variations based on recent collections or herbaria specimen, and on the results given by complementary tools, such as molecular and architectural analysis.

Contribution to the Bryophyte Flora of New Caledonia. I. New Taxa and Amendments

Abstract Seven mosses, Erpodium biseriatum, Floribundaria pseudofloribunda, Leptodictyum riparium, Macromitrium serpens, Rhodobryum aubertii, Sematophyllum phoeniceum, Trichostomum brachydontium, and one liverwort Lepidozia flexuosa, are new for the New Caledonian flora following identification of some gatherings made in 2008 and herbarium specimens at PC and REN. In addition, new localities have been found for three species of mosses recently discovered in the Territory, Anomodon pseudotristis, Calymperes motlei, Euptychium piliferum and two new synonyms are given for Paris nomina nuda, the moss Vesicularia compienei (= V. subfuscescens) and the liverwort Lepidozia etesseana (= Telaranea kogiana). Moreover two doubtful names of the recent checklist of liverworts are rejected after examination of specimens cited from New Caledonia, Lepidozia supradecomposita and Telaranea lawesii and the data of Zoopsis liukiuensis in New Caledonia earlier than its first publication is reported. In spite of the relatively numerous data dealing with it, the knowledge of bryophyte flora in New Caledonia will increase and be clarified by sampling many widely overlooked areas (for example dry forests) and biotopes and re-examination of herbarium collections.

Studies on Lophocoleaceae XXI. Otoscyphus J.J. Engel, Bardat et Thouvenot, a New Liverwort Genus from New Caledonia with an Unusual Morphology

Abstract A new genus of liverwort in the family Lophocoleaceae is described and illustrated. The genus Octoscyphus presents a suite of original characters for this family. It is placed in the subfamily Lophocoleoideae. It has, in particular, a unique feature among leafy liverworts: The leaves have a very broad foliar base forming a longitudinally inserted pocket. The feature involves several characters. This genus is represented by a single species, Otoscyphus crassicaulis comb, nov., from New Caledonia. The species is montane and occurs on the dead, rotted wood.

Microlejeunea strasbergii sp. nov. (Lejeuneaceae) from Réunion Island (Mascarenes)

Abstract Microlejeunea strasbergii J. Bardat & C. Ah-Peng is described from Réunion Island. It differs from Microlejeunea africana Steph. in the larger lobule, the incurved distal margin of the lobe and the apical tooth of the lobule that is almost in contact with the distal margin of the lobe. The new species is described, illustrated, its IUCN status assessed, and an identification key for the genus is provided for the Mascarene archipelago (Réunion, Mauritius and Rodrigues).

Additions to the bryoflora of Réunion Island 2: Anthocerotopsida, Marchantiopsida and Jungermanniopsida from the herbarium of the National Botanic Garden of Belgium

Abstract The collections of liverworts and hornworts from Réunion Island held in the herbarium of the National Botanic Garden of Belgium (BR) were investigated, and 21 hepatics and 1 hornwort are newly reported from the island. Of these, 5 liverworts and 1 hornwort are new for the Index Muscorum region Afr 3 and 5 liverworts are new for the Mascarenes. New illustrations are provided for Herbertus grossevittatus (Steph.) S.W.Arnell ex Grolle and Cheilolejeunea cordigera (Steph.) Grolle.

Functional Diversity of Subalpine Bryophyte Communities in an Oceanic Island (La Réunion)

Abstract Increasing temperature imperils worldwide tropical subalpine and alpine ecosystems with the threat of mountaintop extinctions and a subsequent loss of biodiversity and ecosystem functions. This paper provides a first assessment of functional diversity along a high climatic gradient for bryophytes, which represent a major plant compartment in these ecosystems. The present study takes place on the highlands of the Piton des Neiges volcano, the highest summit of La Réunion Island (Western Indian Ocean). We find a relatively high species richness of bryophytes in these subalpine habitats, with a peak of diversity at 2750 m for the ground-dwelling community. We report a strong linear relationship between functional diversity and species richness for epiphytes. Within the same plant group, the relationship between functional richness, based on eight traits, and elevation differed between the ground-dwelling and epiphytic communities, suggesting that different processes may structure bryophyte species assemblages along this short subalpine climatic gradient. Higher functional redundancy in ground-dwelling bryophyte assemblages indicates that this community may be more robust than epiphytic bryophytes to disturbances in these subalpine ecosystems.