Mitraria Research Articles

A 30-year update of the climbers and vascular epiphytes inventory of the Cerro Ñielol Natural Monument (La Araucanía, Chile): a database.

BackgroundPlant species diversity may be seriously threatened in ecotone zones under global climate change. Therefore, keeping updated inventories of indicator species seems to be a good strategy for monitoring wild areas located in these strips. The database comes from an inventory of climbers and vascular epiphytes conducted in the Cerro Ñielol Natural Monument, a small protected area (89 hectares) located in Chile's Mediterranean-temperate phytogeographic region, within the boundaries of the city of Temuco, La Araucaína Region.The data represent the update of the first inventory carried out between 1980 and 1984. In this current contribution, data collection was carried out in 27 quadrats using the trails as transects. The data provide the record of 45 species (16 climbers, 15 epiphytes and 10 trees), including two accidental epiphytes (Acerpsudoplatanus L. and Gavileaodoratissima (L.) Endl. ex Griseb.), two species that can be found as epiphytes or terricolous (Hymenophyllumtunbrigense (L.) Sm. and Nerteragranadensis (Mutis ex L.f.) Druce) and one species (Chusqueaquila Kunth) that can be found as terricolous and climber. Species of interest were recorded on live trees (n = 51), snags (n = 9), stumps (n = 4), fallen log (n = 5) and on the forest soil (n = 17).The most abundant climbers were Hydrangeaserratifolia (Hook. & Arn.) F. Phil. (n = 77 stems), Lapageria rosea Ruiz & Pav. (n = 70 stems), Raukauavaldiviensis (Gay) Frodin (n = 48 stems) and Cissusstriata Ruiz & Pav. (n = 33 stems). In contrast, the most abundant epiphytes were Hymenophyllumplicatum Kaulf. (n = 1728 fronds) and Hymenophyllumtunbrigense (L.) Sm. (n = 2375 fronds). These latter two species represent the highest frequency and abundance in the whole inventory, respectively. Several ecosystem traits are, in fact, new reports since the first inventory was conducted in 1980-1984; for example, the presence of the filmy fern Hymenophyllumtunbrigense, the record of the climber Elytropuschilensis , fallen logs or the species-host relationship. Accordingly, the database is made available in this manuscript.New informationThis study updates the climbers and vascular epiphyte species list in the Cerro Ñielol Natural Monument, a small patch of forest under severe anthropogenic pressure. This protected area is characterised by floristic elements of the Mediterranean and temperate phytogeographic region of Chile, in a zone where forests have been severely deforested. The database includes the record of 45 species – including six species that were not recorded in the first inventory – in 211 records.The main novelty of this contribution is the systematic classification of species, on ten traits rarely reported in a floristic inventory: (i) species taxonomic identity (as usual), (ii) species abundance (number of stems and fronds), (iii) habit (herb, shrub, subshrub, tree), (iv) growth form (accidental epiphyte, epiphyte, vine, liana, terricolous), (v) climbing mechanism (tendrils, adhesive roots, twining, scrambling), (vi) microhabitat (fallen log, footpath slope, soil, stump, trunk), (vii) host species (where appropriate), (viii) host condition (live, woody debris, snag), (ix) host diameter at breast height (DBH) and (x) target species found over 2.3 m on trees.Thirty years after the first inventory conducted between 1980 and 1984, the climber assemblage has remained relatively stable over time, although there are some differences in species composition. Specifically, the climber Elytropuschilensis are recorded in the current inventory, but the Mitrariacoccinea (recorded in the first inventory) is not present. On the other hand, the epiphyte assemblage showed an increase in the species richness of filmy ferns, with five previously unrecorded species: Hymenophyllumcuneatum, H.dicranotrichum, H.pectinatum, H.peltatum and H.tunbrigense. One of the novel features was the presence of Sarmientascandens and Synammiafeuillei on a Pinusradiata D. Don tree. Additionally, the introduced species Acerpseudoplatanus is included, which is new to the Chilean vascular plant catalogue. All these data are available in the present manuscript.

Regeneration niche of three epiphytic species of Gesneriaceae from Chilean rainforests: implications for the evolution of growth habits in Coronanthereae

Ecological and evolutionary studies of the epiphytic growth habit in angiosperms are limited. In this article, we assess the relationship between growth habit and regeneration niche in Coronanthereae (Gesneriaceae) and discuss its implications for the evolution of epiphytism in this lineage. In the temperate rainforest of southern Chile, we quantified the vertical distribution and experimentally examined the regeneration niche of three endemic species of Coronanthereae. One species was a holoepiphyte, which was more frequent in the upper canopy, and two species were secondary hemiepiphytes, which decreased in abundance with tree height. Seed germination of the holoepiphyte was higher on tree bark substrates and under open canopy than on forest soil and in the shade. In contrast, seed germination of both secondary hemiepiphytes did not differ between substrates (bark vs. soil) or light conditions (light vs. shade). Seedling survival percentage of secondary hemiepiphytes was higher on forest soil and under a closed canopy, thus behaving as shade-tolerant species. In turn, the holoepiphyte behaved as a shadeintolerant species. The reconstruction of the ancestral growth habits and regeneration niches on the inferred phylogenetic tree of Coronanthereae revealed that the specialized regeneration niche of Sarmienta repens, characterized by requirements of shade intolerance and germination on tree bark, was coupled with the evolution of the holoepiphytic growth habit. We conclude that differentiation in the regeneration niche is a key process in the evolution of epiphytic growth habits in Coronanthereae. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 79‐92. ADDITIONAL KEYWORDS: Asteranthera ovata ‐ holoepiphyte ‐ light ‐ Mitraria coccinea ‐ Sarmienta repens ‐ secondary hemiepiphyte ‐ seed germination ‐ seedling survival ‐ substrate.

Differential effects of anthropogenic edges and gaps on the reproduction of a forest-dwelling plant: The role of plant reproductive effort and nectar robbing by bumblebees

Forest fragmentation produces sharp changes in the spatial configuration of remnant forest patches, which include the increasing influence of patch edges on the interior of forest patches (‘edge effects’). Human activities responsible for forest fragmentation tend also to change the internal characteristics of remnant patches, for example, through the creation of gaps by selective logging. While edges and gaps can be expected to cause comparable changes in the micro-environmental conditions of the forest, their effects on forest-dwelling species and their interactions are not necessarily comparable. This study compares the effect of forest edges and anthropogenic gaps on the reproductive success of a self-incompatible epiphytic plant (Mitraria coccinea), mediated by changes in its relationship with mutualists (pollinators) and antagonists (flower larcenists). Mitraria coccinea's flowers are pollinated by hummingbirds and robbed by the bumblebee Bombus dahlbomii. Edges and gaps had comparable positive effects on flower production and fruit set; however, nectar robbing was up to sevenfold higher in patches with numerous gaps and resulted in lower reproductive success (fruit set and total fruit crop). Forest fragmentation studies should therefore avoid treating forest remnants as homogeneous units (i.e. focusing exclusively on their characteristics and connectivity), without taking into account the internal heterogeneity caused by anthropogenic pressures (e.g. gaps and edge effects).

Epiphytic Growth Habits of Chilean Gesneriaceae And the Evolution of Epiphytes Within the Tribe Coronanthereae1

Abstract Three monotypic and endemic genera of epiphytic Gesneriaceae (Gesnerioideae, Coronanthereae) occur in temperate rainforests of southern South America. In this article, intraspecific differences in rooted substrate and interspecific variation in epiphytic growth habits among these three Gesneriaceae species were assessed. The presence or absence of plants on the ground and main rooted substrate when growing epiphytically on trees were used to characterize epiphytic growth habits in two old-growth temperate rainforests of northern Chiloe Island (42°30′S) in Chile. An evolutionary interpretation based on reported phylogenies and morphologies within the Coronanthereae is proposed. Two species of Chilean Gesneriaceae, Mitraria coccinea Cav. and Asteranthera ovata (Cav.) Hanst., originate from the forest floor, then climb on trees while maintaining their main roots in the ground, and are classified as secondary hemiepiphytes. The third species, Sarmienta repens Ruiz & Pav., was found exclusively on tre...

Diversity and host tree preferences of vascular epiphytes and vines in a temperate rainforest in southern Chile

Vines and epiphytes contribute importantly to the biodiversity of temperate rainforests of southern South America. However, compared with their tropical counterparts, these functional groups have received less attention. We evaluated diversity, floristic composition and relative abundance of vascular epiphytes and vines within a humid temperate forest in northern Chiloé Island, southern Chile. We assessed whether epiphyte and vine species exhibit preferences among host tree species and tested whether species richness on tree hosts differs from that expected by chance, by comparing observed frequencies of occurrence (FO) and species richness with randomly simulated frequency distributions generated under the assumption of no epiphyte preferences. Finally, we tested for associations of epiphyte and vine species with host tree size (trunk diameter at breast height). Eleven species of ferns and nine angiosperms (seven vines, one epiphytic angiosperm and one shrub) were recorded growing epiphytically in a sample of 499 trees. The most abundant species were three vines, Luzuriaga polyphylla (Hook.) Macbr., Griselinia racemosa (Phil.) Taub. and Mitraria coccinea Cav., and five species of filmy ferns (Hymenophyllaceae). Most epiphytes and vines (65%) showed preference for one or two tree species, with seven species being overrepresented on Podocarpus nubigena Lindl. hosts and 10 underrepresented on Drimys winteri J.R. et G.Forster. Epiphyte and vine species richness was significantly lower than expected by chance on D. winteri and higher than expected on Nothofagus nitida (Phil.) Krasser. Three epiphytic ferns showed preferences for large-sized trees, while frequency of occurrence of three common vines was independent of host tree size.

Mitrariosides, Five Bitter Labdane Glycosides fromMitraria coccinea (Gesneriaceae)

From Mitraria coccinea Cav. (Gesneriaceae), five strongly bitter labdane glycosides named mitrariosides A1, A2, B, C and D (1 — 5) were obtained. The structures were deduced by chemical and spectroscopic evidence (COSY, 13C-1H CORR, NOESY and MS-FAB) and found to be: mitrarioside A1 (1): (6S)-19-(β-D-galactopyranosyloxy)-6-hydroxy-15-(α-Lrhamno-pyranosyloxy)labda-8(17),13-diene, mitrarioside A2 (2): (6S)-19-(β-D-glucopyranosyloxy)-6-hydroxy-15-(α-L-rhamnopyranosyloxy)labda-8(17),13-diene, mitrarioside B (3):(6S)-19-(β-D-glucopyranosyloxy)-6-hydroxy-15-(β-D-glucopyranosyloxy)-labda-8(17),13-diene, mitrarioside C (4): (6S)-19-(β-D-glucopyranosyloxy)-6,15-dihydroxylabda-8(17), 13-diene, and mitrarioside D (5): (6S)-19-(α-L-rhamnopyranosyloxy)-6,15-dihydroxy-labda-8(17),13-diene. The known compounds acteoside and calceolarioside C were also isolated.

A Comparison of Spatial Patterns of Trees in Some Tropical and Temperate Forests

A Comparison of Spatial Patterns of Trees in Some Tropical and Temperate Forests