24 research outputs found
Discovery of a second population of the Critically Endangered Madagascan suicide palm Tahina spectabilis
Grasses of the Isalo National Park, Madagascar – checklist, origins, and significance
Grasses are one of the best documented plant families worldwide in terms of taxonomy, but they are still poorly known in Madagascar. Our understanding of their diversity remains incomplete since grasses and grasslands are assumed by many tobe weeds and degraded wastelands. This project aimed to list thegrasses in Isalo National Park (NP) in order to understand theirdiversity and endemicity, as well as the history of Isalo’s grasslands. Examination of herbarium specimens and new field inventories allowed us to confirm 589 records of grass occurrences in ourstudy area. They were assigned to 112 species, of which 38 species are new records for Isalo NP. The Isalo grass flora includes seven of the eleven Poaceae subfamilies present in Madagascar and is particularly rich in Panicoideae, which make up 65% of the species. Nearly 22% of the grass species of Isalo are endemic to Madagascar, of which three species and one variety are restricted to Isalo massif, including two unusual ground cover species Tristachya humbertii A.Camus and Tristachya [Isalus isalensis]. Open grasslands harbour the highest diversity of grass species, followed closely by riparian forests. The history of the management of Isalo NP by the Bara people, as well as the endemism and the native origin of its grasses and other species are consistent with an ancient origin of Isalo’s ecosystems. We urge that the conservation of Isalo’s grassy ecosystems, as well as that of the plants and animals that inhabit them be prioritized.Les graminées sont parmi les familles de plantes les mieux documentées au niveau mondial en termes de taxonomie, mais sont encore mal connues à Madagascar. Notre compréhension de leur diversité reste incomplète, vu que les graminées et les savanes sont considérées par beaucoup comme des mauvaises herbes et des friches dégradées. Ce projet visait à établir une liste des graminées connues du Parc National (PN) de l’Isalo, afin de comprendre leur diversité et leur endémicité, ainsi que l’histoire des écosystèmes herbeux de l’Isalo. L’examen des spécimens d'herbiers et les nouveaux inventaires sur terrains nous ont permis de générer 589 occurrences de graminées de notre site d’étude. Elles ont été attribuées à 112 espèces de Poaceae, dont 38 sont de nouvelles collectes pour le massif de l’Isalo. La flore herbacée du massif de l'Isalo comprend sept des onze sous-familles de Poaceae présentes à Madagascar et est particulièrement riche en Panicoideae qui représentent 65% des espèces. Près de 22% des espèces de graminées de l’Isalo sont endémiques de Madagascar, dont trois espèces et une variété sont restreintes à Isalo, y compris les deux espèces de plantes couvre-sols inhabituelles Tristachya humbertii A.Camus et Tristachya [Isalus isalensis]. Les prairies ouvertes abritent la plus grande diversité d'espèces de graminées, suivies de près par les forêts ripicoles. L’histoire de la gestion du PN de l’Isalo par les habitants de la région du groupe Bara, ainsi que l’endémisme et l’origine autochtone de ses graminées et autres espèces sont cohérents avec une origine ancienne des écosystèmes de l’Isalo. Nous préconisons instamment que la conservation de ces prairies et savanes de l'Isalo, ainsi que les plantes et les animaux qui les habitent soit priorisée
Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis.
Madagascar is home to 208 indigenous palm species, almost all of them endemic and >80% of which are endangered. We undertook complete population census and sampling for genetic analysis of a relatively recently discovered giant fan palm, the Critically Endangered Tahina spectablis in 2008 and 2016. Our 2016 study included newly discovered populations and added to our genetic study. We incorporated these new populations into species distribution niche model (SDM) and projected these onto maps of the region. We developed population matrix models based on observed demographic data to model population change and predict the species vulnerability to extinction by undertaking population viability analysis (PVA). We investigated the potential conservation value of reintroduced planted populations within the species potential suitable habitat. We found that the population studied in 2008 had grown in size due to seedling regeneration but had declined in the number of reproductively mature plants, and we were able to estimate that the species reproduces and dies after approximately 70Â years. Our models suggest that if the habitat where it resides continues to be protected the species is unlikely to go extinct due to inherent population decline and that it will likely experience significant population growth after approximately 80Â years due to the reproductive and life cycle attributes of the species. The newly discovered populations contain more genetic diversity than the first discovered southern population which is genetically depauperate. The species appears to demonstrate a pattern of dispersal leading to isolated founder plants which may eventually lead to population development depending on local establishment opportunities. The conservation efforts currently put in place including the reintroduction of plants within the species potential suitable habitat if maintained are thought likely to enable the species to sustain itself but it remains vulnerable to anthropogenic impacts
Madagascar’s extraordinary biodiversity: Threats and opportunities
Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as themost prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar
Madagascar’s extraordinary biodiversity: Evolution, distribution, and use
Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique living laboratory for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity
950. XYLOOLAENA PERRIERI
Xyloolaena perrieri F. Gérard belongs to the Sarcolaenaceae, the largest Madagascar endemic plant family. It is illustrated here, and its habitat and conservation status are discussed. As explained below, the spelling of the generic name Xylolaena is sometimes preferred over the commonly used Xyloolaena
Familles endémiques de Madagascar. IX. Une nouvelle espèce de <i>Schizolaena</i> (Sarcolaenaceae) de la forêt littorale
Schizolaena raymondii est décrite ; elle est connue d’une seule parcelle de forêt littorale de basse altitude dans le NE de Madagascar, un des écosystèmes malgaches floristiquement les plus riches mais aussi parmi les plus menacés. Une illustration est fournie et la nouvelle espèce est comparée aux autres membres du genre. Elle se rapproche en particulier de trois autres espèces dont elle partage les feuilles épaisses à apex arrondi à aigu, mais dont elle se distingue par des pétales plus longs et une combinaison caractéristique de longueurs de limbes foliaires et de pédoncules. Une analyse préliminaire du statut de conservation selon les critères des Listes Rouges de l’UICN indique que S. raymondii est à rattacher à la catégorie « en danger critique d’extinction ».Schizolaena raymondii is described from a single stand of low-elevation littoral forest in NE Madagascar, one of the island’s floristically richest and most highly threatened ecosystems. The new species is illustrated and compared to other members of the genus; it most closely resembles three congeners with which it shares thick leaves with a rounded to acute apex, but is distinguished by having longer petals and a unique combination of leaf blade and peduncle lengths. Schizolaena raymondii is assigned a preliminary conservation status of Critically Endangered using the IUCN Red List criteria.</p
Bulbostylis itremoensis (Abildgaardieae, Cyperaceae), a new sedge species from Madagascar
An endemic species of Bulbostylis (Abildgaardieae, Cyperaceae) from Madagascar is described as new to science. Bulbostylis itremoensis is only known from two localities: the Itremo and Isalo massifs in the province of Fianarantsoa. The species can be recognised by its habit with numerous crowded culms, leaves and thick, soft roots with an outer mycorrhizal layer. Its culm is hairy, angular with about 10 rounded longitudinal ridges without conspicuous surface cells. The leaf sheaths are light brown to straw-coloured with numerous longitudinal nerves, densely short-hairy on the nerves but with numerous flexuose whitish hairs at their oblique orifices. Its inflorescence is a dense hemispherical head of c. 15 crowded spikelets with many erect or spreading involucral bracts. Its glumes are ovate, densely scabrid of which medium-reddish brown with a prominent 1 – 3-nerved green midrib ending below the obtuse apex or excurrent into a short mucro. This species is described, illustrated and compared to the other species of Bulbostylis that occur in the Itremo Massif Protected Area
Eugenia stictophylla N. Snow & Razafim. 2012, sp. nov.
<i>Eugenia stictophylla</i> N. Snow & Razafim., <i>sp. nov.</i> (Figs. 2, 6). <p> <i>A congeneribis madagascariensibus combinatione characterum sequentium distinguitur: arbor 4–7 m alta; petioli 3.5- 5.5 mm longi, sulcati; folia 20–50 mm longa, 7–12(–15) mm lata, anguste elliptica, basi cuneata, apice obtuso, lamina dense glandulosa; petala alba; stamina 35–70.</i></p> <p> <b>Type:</b> ― MADAGASCAR. Prov. Toliara: District Tolagnaro; forêt de Petriky. 25°05’S, 46°52’E, 5 December 1990, <i>N. Dumetz 1106 & G. McPherson</i> (holotype MO! [sheet no. 3778655]; isotypes BISH! [sheet no. 747508], MO, P, TAN).</p> <p> <i>Trees</i> 4–7 meters. Indumentum (where present) shortly sericeous, trichomes dibrachiate and ferrugineous. <i>Branchlets</i> laterally compressed and maroon or pinkish on emergence, becoming terete and grayish (dried), smooth, sericeous below the base of (often supra-axillary) pedicels but glabrous or only sparsely sericeous elsewhere; oil glands sparse, indistinct; internodes 1.0– 2.2 cm long. Stipules of short, setose hairs (type A: Snow <i>et al.</i> 2003:7). <i>Leaves</i> thinly coriaceous, mostly evenly spaced on branchlets, secondary veins faintly protruding above (dried material), slightly discolorous, somewhat glossy above, matte below; venation (obscurely) brochidodromous. <i>Petioles</i> 3.5–5.5 mm long, deeply sulcate adaxially, prominently glabrescent along apex of sulcus, abaxially verrucose. <i>Leaf blades</i> 2.0–5.0 x 0.7–1.2(–1.5) cm, narrowly elliptic, base strongly cuneate, margin flat or drying slightly revolute, obtuse; adaxial surface glabrescent, secondary nerves indistinct and somewhat protruding (dried material), oil glands small but dense (use magnification), midvein sulcate proximally but becoming flush distally; abaxial surface glabrous, oil glands much less prominent than above, secondary veins obscure (sometimes scarcely visible), of 10–14 pairs, intramarginal vein indistinct, closely paralleling margin, ca. 0.5 mm from margin at midpoint of blade. <i>Inflorescence</i> a solitary flower, axillary or (mostly) supra-axillary. <i>Peduncles</i> 7–12(–15) mm long, laterally compressed (dried), mostly ascending, somewhat flexuous, sericeous near base but more sparsely distally, oil glands faint, moderately common. <i>Bracteoles</i> 2, 0.5–1.0 mm long x <0.5 mm, ovate to broadly ovate, scale-like, stiffly erect to ascending, stiff, sparsely sericeous, persisting in flower. <i>Hypanthium</i> 1.5–2.0 mm long (dried), ca. 1.3–2.4 mm wide below base of calyx lobes, obconic, terete, sparsely sericeous (especially above base of bracteoles towards calyx lobes), oil glands small but dense. Ovary apex sparsely short-villous along outer edges (i.e., in region adjacent to inner margin of staminal ring). <i>Calyx lobes</i> 4, 1.5–3.0 mm long, distinct and dimorphic in bud (the inner 2 somewhat longer than the outer 2), orbicular to shortly to broadly ovate, ciliate and sparsely sericeous, densely glandular (glands larger and more protruding than those of hypanthium), persistence in fruit unknown. <i>Petals</i> 4, 5– 7 mm long, (2.5–)3.5–4.0 mm wide, obovate or widely obovate, white, glabrous, oil glands common and of similar size to those of calyx lobes. <i>Stamens</i> 35–70, in several whorls; filaments 3–6 mm long; anthers 0.5–0.8 mm long, globose to subcylindrical, sub-basifixed, with a single prominent apical gland. <i>Style</i> 4.5–5 mm long, glabrous, tapering to a narrow punctiform stigma. Locules 2; placentation parietal, placenta capitate from middle of locule; ovules 8–13 per ovary, radiating from placenta. <i>Fruit</i> ca. 2–3 x 2–3 cm, yellowish-brown.</p> <p> <b>Field characters:</b> ―Trees 4–7 meters. Petioles deeply sulcate above; leaves densely glandular on upper surface, narrowly elliptic, apically obtuse. Petals white.</p> <p> <b>Distribution:</b> ―Known only from Petriky and Ambinanibe forests west of Tolagnaro.</p> <p> <b>Habitat and ecology:</b> ―Littoral forests on sand; elevation to about 15 m.</p> <p> <b>Phenology:</b> ―Flowering December and January; fruits not known.</p> <p> <b>Etymology:</b> ―The specific epithet is derived from the Greek elements <i>stict</i> and <i>phyll</i> in reference to the densely glandular leaves.</p> <p> <b>Additional specimen examined (paratype):</b> ― MADAGASCAR. Prov. Toliara: Tolagnaro region; SW of town in forest called Petriky, along QIT road, 25°05’S, 46°52’E, 12 January 1990, <i>G. McPherson 14774 et al.</i> (G, K!, MO!, P, TAN).</p> <p> <b>Conservation status:</b> ―The imprecise geo-coordinates preclude knowing whether the two specimens occur(ed) in conservation zone P1 of Petriky Forest (Fig. 2; see also Lowry <i>et al</i>. 2008). With just two collections from a restricted forest, an AOO of 9 km 2, and a single subpopulation constituting a single location with an estimated number of less than 250 individuals, near or within a protected area (Petriky), <i>E</i>. <i>stictophylla</i> is assigned a preliminary status of “Endangered” (EN: D).</p> <p> <b>Discussion:</b> ―Our reports of fruiting material are taken from the field and from information provided by people locally who know the species. Among other species of <i>Eugenia</i> in the vicinity of Petriky Forest, <i>Eugenia stictophylla</i> most closely resembles <i>Eugenia cassinoides</i> Lam. However, <i>E. stictophylla</i> has a more deeply sulcate petiole, more narrowly elliptic leaf blades, denser and much darker laminar oil glands (living and dried material), and more flexible pedicles. The leaf blades of the new species tend to dry significantly greener than those of <i>E. cassinoides</i>, the latter of which typically dry darkish brown adaxially, although the dried color may be an artifact of drying temperatures and duration.</p> <p> The paratype specimen of <i>E. stictophylla</i> may be slightly introgressed with the much more common <i>E. cassinoides</i>, although genetic studies would be necessary to test this hypothesis. Differences of the paratype from the type gathering include fewer stamens (ca. 35–45 v. 60–70), subglobular (v. cylindrical) anther sacs, and fewer (8–9 v. 11–13) ovules per locule.</p>Published as part of <i>Snow, Neil, Rabenantoandro, Johny, Randriatafika, Faly, Rabehevitra, David, Razafimamonjy, N. Darie & Cable, Stuart, 2012, Studies of Malagasy Eugenia (Myrtaceae) - III: Seven new species of high conservation concern from the eastern littoral forests, pp. 39-60 in Phytotaxa 48 (1)</i> on pages 49-51, DOI: 10.11646/phytotaxa.48.1.7, <a href="http://zenodo.org/record/4776766">http://zenodo.org/record/4776766</a>
Eugenia roseopetiolata N. Snow & S. Cable 2012, sp. nov.
Eugenia roseopetiolata N. Snow & S. Cable, sp. nov. (Figs. 2, 7). A congeneribis madagascariensibus combinatione characterum sequentium distinguitur: petioli rubri glandulis prominentibus flavidis; bracteolae breves et appressae; filamenta et petala albida. Type: ― MADAGASCAR. Prov. Toliara: SW of Ft. Dauphin in Petriky Forest, W side of forest tract N of Lake Andrato lohorano, block P-1 of QIT-FER, 25°04'S, 46°49'E, 15 m, 19 November 1990, D. Faber-Langendoen 3557 (holotype MO! [sheet no. 4029290]). Tree to 4 meters. Indumentum on vegetative and reproductive parts shortly sericeous-villous (trichomes dibrachiate and mostly somewhat ferrugineous). Branchlets laterally compressed, smooth to slightly irregular, moderately sericeous, light brown; oil glands not visible; internodes ca. 1–2 cm long. Leaves thinly coriaceous, concentrated near branchlet tips, glossy emerald green above but dull (matte) citrine below (fresh; brownish when dry); venation brochidodromous. Stipules absent. Petioles 4.0– 6.5 mm long, deeply sulcate above, bright magenta to maroon (the pigment often extending into base of midrib and proximal region of laminar margin), oil glands prominent and distinctly yellowish in younger material, sericeous above (especially on emergence). Leaf blades (2.8–)4.0–4.7 x 1.8–2.3 cm, mostly elliptic (rarely obovate), base cuneate, apex and tip obtuse, margin slightly revolute, surface flat; adaxial surface sparsely sericeous (proximally) on emergence but becoming glabrate, oil glands indistinct but numerous (especially visible near base and along proximal margins), midvein slightly sulcate (proximally, becoming flush distally); abaxial surface sparsely sericeous-villous (becoming glabrate), oil glands moderate to common, faint (fresh of dried), secondary veins visible but not prominent; intramarginal vein 1.0– 1.5 mm from laminar margin at midpoint. Inflorescence a solitary axillary flower, or arising from a short brachyblast; pedicel 4–8. 5 mm long, terete, shortly sericeous-villous (trichomes dibrachiate), stiff but sometimes slightly curved, light green (fresh), often with minute triangular bract at base (bract with numerous oil glands of various sizes; apex of bract greenish or light brown). Bracteoles 0.5–0.8 mm long, ovate, scale-like, erect and stiffly appressed (in flower) against base of hypanthium (apex of pedicel slightly swollen underneath base of each bracteole), moderately sericeous. Hypanthium 2.0– 2.4 mm long, ca. 2.0 mm wide at base of calyx lobes, obconic, terete and light green (fresh), moderately sericeous-villous, ovary apex glabrous. Buds light green, densely but faintly yellowish-glandular, sparsely sericeous (trichomes dibrachiate, often brownish). Calyx lobes 4, 1.5–2.3 mm long, dimorphic (2 longer, 2 shorter), light yellow-green (when fresh), rounded, sparsely dibrachiate-sericeous above and below, oil glands below of distinctly different sizes, prominent and slightly protruding. Petals 4, 5.0– 5.7 mm long, widely ovate, glabrous above and below, white, sparsely and faintly glandular, relatively thick. Staminal ring densely short-villous, ca. 2.5 mm wide. Stamens ca. 90–110; filaments 2.5–5.5 mm, white; anther sacs ca. 0.7 mm long, subcylindrical, sub-basifixed, cream colored, apical gland on connective faint. Style ca. 6 mm long (material scant), glabrous, white; stigma terete but scarcely if at all capitate. Ovary bilocular; placentation axile; ovules arising from center of placenta. Fruit unknown. Field characters:— Petioles bright magenta to maroon, sulcate and slightly sericeous above; leaf blades 4-4.7 cm long; petals, filaments and style white. Distribution:— Petriky Forest (Fig. 2). Habitat and ecology:— White sand littoral forest. Phenology:— Flowering in November. Fruits unknown. Additional specimen examined (paratype): ― MADAGASCAR. Prov. Toliara: Petriky (Vohibary), 25°3'6.68"S, 46°53'45.24"E, 21 February 2007, E. Landry P165 (K! [seed source for Millenium Seed Bank], TAN). Etymology:— A Latinization that refers to the bright reddish petiole in living material. Conservation status:— The species is known from Petriky forest. With just two collections (Fig. 7) from a restricted forest, an AOO of 9 km 2, and a single subpopulation constituting a single location with an estimated number of less than 250 individuals, encompassed within or near a protected area (Mandena), E. rosapetiolata is assigned a preliminary status of "Endangered" (EN: D). Although field studies have not attempted to count the number of individuals, substantial collecting in Petriky since the 1980s likely would found additional specimens if E. roseopetiolata were more common. Also, given that Eugenia arenicola, E. cassinoides, and E. cloiselii have been collected in the same general area in greater numbers, we tentatively estimate the total population of E. rosapetiolata to be less then 250 individuals. Discussion:— Eugenia roseopetiolata most closely resembles E. cassinoides, but several aspects of the former appear to be distinct from the latter, including: the reddish color of the petioles that extends into the lower leaf margins and somewhat into the midvein of the laminar surface, and prominent yellowish oil glands on the petiole (Fig. 7). Additional study of fresh material of E. roseopetiolata, E. cassinodies, and related material will be necessary to better understand variation between these taxa.Published as part of Snow, Neil, Rabenantoandro, Johny, Randriatafika, Faly, Rabehevitra, David, Razafimamonjy, N. Darie & Cable, Stuart, 2012, Studies of Malagasy Eugenia (Myrtaceae) - III: Seven new species of high conservation concern from the eastern littoral forests, pp. 39-60 in Phytotaxa 48 (1) on pages 51-53, DOI: 10.11646/phytotaxa.48.1.7, http://zenodo.org/record/477676