Bird species inventory in secondary tropical montane cloud forest at Cloudbridge Nature Reserve, Talamanca Mountains, Costa Rica

The tropical montane cloud forests (TMCF) of the Talamanca Mountains of Costa Rica are a unique and understudied habitat that is home to a high number of endemic bird species. Cloudbridge Nature Reserve is a TMCF reforestation reserve lying on the Pacific slope of Cerro Chirripó in the cantón of Pérez Zeledón. Here, we synthesize data collected at Cloudbridge between March 2016 and May 2020 from multi-year point count, walking, call-playback, and camera trap surveys along with photographs collected from February 2007 to April 2021 to present a bird species inventory of the reserve. In total, 204 bird species from 40 families, including 40 endemic species, were identified, and monthly presence summarized for each species. We discuss the implications of our findings for understanding TMCF avian communities, as well as the importance of year-round surveys using a variety of techniques to better capture overall avian diversity.

Ascomycetes from the relic forest of Oreomunnea mexicana, Oaxaca, Mexico

La Esperanza is an Oaxacan relic area of the Tertiary, dominated by the big tree Oreomunnea mexicana (Juglandaceae). The forest is part of the priority region for the conservation of La Chinantla and constitutes one of the most conserved Mexican tropical montane cloud forests. We studied the Ascomycetes fungi and found 63 species, of which 32 are new records for Oaxaca. Ascocoryne inflata, Calyculosphaeria macrospora, Cercophora costaricensis, Chaetosphaeria ellisii, Coccomyces limitatus, Lasiosphaeria ovina, Leptogidium dendriscum, Marthamyces quadrifidus, Stereocaulon didymicum and Thelonectria lucida are new records for Mexico. Xylaria was the most diverse genus with 12 species. The most abundant species were Xylaria arbuscula and Lachnum apalum. The main growth habit was lignicolous. The tropical montane cloud forest of La Esperanza has unique characteristics allowing great taxonomic diversity of Ascomycetes.

Climate change and deforestation drive the displacement and contraction of tropical montane cloud forests

Global climate change and habitat loss are displacing tropical montane forests along mountain slopes1–4. Cloud forests are one of the most diverse and fragile of these montane ecosystems5–8, yet little is known about the historical and ongoing impacts of anthropogenic disturbances on these forests. Here we assess historical (1901–2016) changes in the altitudinal range of vascular plant species in Mesoamerican cloud forests and evaluate the relative impacts of climate change and land-use alterations. By analysing thousands of occurrence records from public biological collections, we uncovered common altitudinal shifts across species and suggest an overall contraction of cloud forests starting in the late 1970s. We infered a pervasive and interrelated impact of rising temperatures, changing precipitation patterns, and deforestation on the distribution of cloud forest species across Mesoamerica. Over the last fifty years, cloud forests have declined due to deforestation and warmer and more (seasonally) arid climates9–11. This is pushing species’ to contract their altitudinal ranges and may lead to an increasing probability of abrupt and devastating declines of population sizes, local adaptation, and migration.

Leaf Vein Morphological Variation in Four Endangered Neotropical Magnolia Species along an Elevation Gradient in the Mexican Tropical Montane Cloud Forests

Climatic variations influence the adaptive capacity of trees within tropical montane cloud forests species. Phenology studies have dominated current studies on tree species. Leaf vein morphology has been related to specific climatic oscillations and varies within species along altitudinal gradients. We tested that certain Neotropical broad leaf Magnolia species might be more vulnerable to leaf vein adaptation to moisture than others, as they would be more resilient to the hydric deficit. We assessed that leaf vein trait variations (vein density, primary vein size, vein length, and leaf base angle) among four Magnolia species (Magnolia nuevoleonensis, M. alejandrae, M. rzedowskiana, and Magnolia vovidesii) through the Mexican Tropical montane cloud forest with different elevation gradient and specific climatic factors. The temperature, precipitation, and potential evaporation differed significantly among Magnolia species. We detected that M. rzedowskiana and M. vovidesii with longer leaves at higher altitude sites are adapted to higher humidity conditions, and that M. nuevoleonensis and M. alejandrae inhabiting lower altitude sites are better adjusted to the hydric deficit. Our results advance efforts to identify the Magnolia species most vulnerable to climate change effects, which must focus priorities for conservation of this ecosystem, particularly in the Mexican tropical montane cloud forests.

A new species of climbing Chamaedorea (Arecaceae) from Chiapas, Mexico

Chamaedorea tacanensis (Arecaceae), a new species from the Tacaná Volcano Biosphere Reserve, Chiapas, Mexico, is described based on morphological and phylogenetic data. It is morphologically similar to C. elatior, the only other climbing species in the genus. However, C. tacanensis is distinguished by having linear pinnae (lanceolate in C. elatior), petioles emerging glaucous (glabrous in C. elatior), and longer rachises, blades and peduncles than C. elatior. Also, C. tacanensis has pinnate-leaved seedlings and juveniles, whereas they are simple or bifid in C. elatior. The two taxa form separate monophyletic groups. Geographically, C. tacanensis is found in tropical montane cloud forests of the Pacific slope whereas C. elatior mostly occurs in lowland tropical forests of the Atlantic slope. Chamaedorea tacanensis has been recorded in only three localities: two in the Tacaná Volcano Biosphere Reserve, Mexico, and one in San Marcos, Guatemala. Further floristic studies in surrounding areas might better clarify the geographic distribution range of this species.

New records of Ascomycetes from the Tropical Montane Cloud Forests of eastern Mexico

The tropical montane cloud forest is an important reservoir of the diversity of Mexican ascomycetes. We cite and describe 17 species that had not been recorded in this vegetation type. Fifteen of them are new records for Mexico. Some of these species are associated with angiosperms and some with other fungi. Ongoing efforts are required to carry out floristic, taxonomic, phylogenetic and ecological studies of this group of fungi in such a diverse ecosystem that is cataloged as threatened.