Tracking Cloud Forests With Cloud Technology and Random Forests

Hotspots of endemic biodiversity, tropical cloud forests teem with ecosystem services such as drinking water, food, building materials, and carbon sequestration. Unfortunately, already threatened by climate change, the cloud forests in our study area are being further endangered during the Covid pandemic. These forests in northern Ecuador are being razed by city dwellers building country homes to escape the Covid virus, as well as by illegal miners desperate for money. Between August 2019 and July 2021, our study area of 52 square kilometers lost 1.17% of its tree cover. We base this estimate on simulations from the predictive model we built using Artificial Intelligence, satellite images, and cloud technology. When simulating tree cover, this model achieved an accuracy between 96 and 100 percent. To train the model, we developed a visual and interactive application to rapidly annotate satellite image pixels with land use and land cover classes. We codified our algorithms in an R package—loRax—that researchers, environmental organizations, and governmental agencies can readily deploy to monitor forest loss all over the world.

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.

Dry-Season Fog Water Utilization by Epiphytes in a Subtropical Montane Cloud Forest of Southwest China

Fog water is generally considered to be an important water source for epiphytes in cloud forests because they cannot directly access ground-level water sources. However, the water use proportions of potential water sources and water use efficiency of epiphytes in the subtropical montane cloud forests (MCF) remain to be further explored. In this study, we investigated the water use pattern in the dry season and the intrinsic water use efficiency (WUEi) of four epiphyte groups (i.e., epiphytic lichens, epiphytic bryophytes, epiphytic ferns, and epiphytic seed plants) using stable isotope (δ2H, δ18O, and δ13C) techniques. Our results indicated that the water sources of epiphytes were significantly different among groups and species. The contribution proportions of fog water to epiphytic lichens, epiphytic bryophytes, epiphytic ferns, and epiphytic seed plants were 83.2%, 32.7%, 38.8% and 63.7%, respectively. Epiphytic lichens and epiphytic seed plants mainly depended on fog water whereas the epiphytic bryophytes and epiphytic ferns relied on both fog water and humus. This may be due to their differences in morphological and structural traits (e.g., thallus or leaves, rhizoid or roots). Additionally, the difference in was also significant among epiphyte groups and species, which could be related to their different water acquisition patterns. In conclusion, our study reveals the differentiation of water utilization in epiphytes and confirms the importance of fog water for epiphytes during the dry season.

Notes on the systematics of Cuscuta sect. Subulatae (subg. Grammica) with the description of Cuscuta mantiqueirana, a new species from Brazil

Cuscuta mantiqueirana Costea, S.S. Silva & Sim.-Bianch. a new species from montane cloud forests of the Serra da Mantiqueira, Brazil, is described and illustrated. The morphological and phylogenetic analyses revealed that the new species belongs to sect. Subulatae of subg. Grammica. The new species is related to C. odorata var. botryoides, C. rotundiflora and C. globiflora from which it differs in narrower calyx lobes and the presence of four stomatiferous lobes or projections at the distal part of the ovary. A detailed morphological comparison with C. odorata var. botryoides, morphologically the most similar taxon, is provided along with the geographical distribution, ecology and host range of the species. The morphological and phylogenetic relationships of the new species, as well as the diversity of stomatiferous projections, are discussed in the broader context of sect. Subulatae and subg. Grammica. Cuscuta boliviana var. paranensis is considered a synonym of C. odorata var. botryoides.

Longhorned woodboring beetles (Coleoptera, Cerambycidae) from Cusuco National Park, Honduras: new species, new records, and revalidation

An ongoing study of the longhorned beetle fauna in the cloud forests of Cusuco National Park revealed multiple additions to the Honduran fauna. Four new species are described: Heterachthes caceresae sp. nov. (Cerambycinae, Neoibidionini), Oreodera kawasae sp. nov. (Lamiinae, Acrocinini), Phrynidius guifarroi sp. nov. (Lamiinae, Apomecynini), and Strangalia lunai sp. nov. (Lepturinae, Lepturini). Additionally, Lagocheirus parvulus Casey, 1913 (Lamiinae, Acanthocinini) is revalidated as Lagocheirus araneiformis parvulus Casey, 1913 (Lagochirus [sic]). We recorded Arixiuna varians (Bates, 1881) (Lamiinae, Hemilophini) for the first time for Honduras. These findings confirm how poorly the invertebrate biodiversity of cloud forests is documented and hints at the large number of species we are losing with the ongoing deforestation.

Small-scale variation in a pristine montane cloud forest: evidence on high soil fungal diversity and biogeochemical heterogeneity

Montane cloud forests are fragile biodiversity hotspots. To attain their conservation, disentangling diversity patterns at all levels of ecosystem organization is mandatory. Biotic communities are regularly structured by environmental factors even at small spatial scales. However, studies at this scale have received less attention with respect to larger macroscale explorations, hampering the robust view of ecosystem functioning. In this sense, fungal small-scale processes remain poorly understood in montane cloud forests, despite their relevance. Herein, we analyzed soil fungal diversity and ecological patterns at the small-scale (within a 10 m triangular transect) in a pristine montane cloud forest of Mexico, using ITS rRNA gene amplicon Illumina sequencing and biogeochemical profiling. We detected a taxonomically and functionally diverse fungal community, dominated by few taxa and a large majority of rare species (81%). Undefined saprotrophs represented the most abundant trophic guild. Moreover, soil biogeochemical data showed an environmentally heterogeneous setting with patchy clustering, where enzymatic activities suggest distinctive small-scale soil patterns. Our results revealed that in this system, deterministic processes largely drive the assemblage of fungal communities at the small-scale, through multifactorial environmental filtering.