Measurement report: Impact of African aerosol particles on cloud evolution in a tropical montane cloud forest in the Caribbean

African aerosol particles, traveling thousands of kilometers before reaching the Americas and the Caribbean, directly scatter and absorb solar radiation and indirectly impact climate by serving as cloud condensation nuclei (CCN) or ice-nucleating particles (INPs) that form clouds. These particles can also affect the water budget by altering precipitation patterns that subsequently affect ecosystems. As part of the NSF-funded Luquillo Critical Zone Observatory, field campaigns were conducted during the summers of 2013 (23 d), 2014 (11 d), and 2015 (92 d) at Pico del Este, a site in a tropical montane cloud forest on the Caribbean Island of Puerto Rico. Cloud microphysical properties, which included liquid water content, droplet number concentration, and droplet size, were measured. Using products from models and satellites, as well as in situ measurements of aerosol optical properties, periods of high- and low-dust influence were identified. The results from this study suggest that meteorology and air mass history have a more important effect on cloud processes than aerosols transported from Africa. In contrast, air masses that arrived after passing over the inhabited islands to the southeast led to clouds with much higher droplet concentrations, presumably due to aerosols formed from anthropogenic emissions.

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.

Influence of Pleistocene climatic oscillations on the phylogeography and demographic history of endemic vulnerable trees (section Magnolia) of the Tropical Montane Cloud Forest in Mexico

The Tropical Montane Cloud Forest (TMCF) is a highly dynamic ecosystem that has undergone frequent spatial changes in response to the interglacial-glacial cycles of the Pleistocene. These climatic fluctuations between cold and warm cycles have led to species range shifts and contractions-expansions, resulting in complex patterns of genetic structure and lineage divergence in forest tree species. In this study, we sequenced four regions of the chloroplast DNA (trnT-trnL, trnK5-matk, rpl32-trnL, trnS-trnG) for 20 populations and 96 individuals to evaluate the phylogeography, historical demography, and paleodistributions of vulnerable endemic TMCF trees in Mexico: Magnolia pedrazae (north-region), M. schiedeana (central-region), and M. schiedeana population Oaxaca (south-region). Our data recovered 49 haplotypes that showed a significant phylogeographic structure in three regions: north, central, and south. Bayesian Phylogeographic and Ecological Clustering (BPEC) analysis also supported the divergence in three lineages and highlighted the role of environmental factors (temperature and precipitation) in genetic differentiation. Our historical demography analyses revealed demographic expansions predating the Last Interglacial (LIG, ~125,000 years ago), while Approximate Bayesian Computation (ABC) simulations equally supported two contrasting demographic scenarios. The BPEC and haplotype network analyses suggested that ancestral haplotypes were geographically found in central Veracruz. Our paleodistributions modeling showed evidence of range shifts and expansions-contractions from the LIG to the present, which suggested the complex evolutionary dynamics associated to the climatic oscillations of the Pleistocene. Habitat management of remnant forest fragments where large and genetically diverse populations occur in the three TMCF regions analyzed would be key for the conservation of these magnolia populations.

MOSS AS BIOINDICATORS FOR POLLUTION AT FRASER HILL AND CAMERON HIGHLAND PAHANG MALAYSIA

Tropical Montane Cloud Forest (TMCF) is one of Earth’s most neglected ecosystems around the globe. More than half of these forests are situated within Southeast Asia. Malaysia is known for its numerous mountains that are exceptionally rich in biodiversity and locally endemic species, but they are also threatened by expanding human activity such as forestry, agriculture, infrastructure, and climate change. The study aims to critically assess the current state of moist TMCF, focusing on their physical and biological potentials as Bio indicators through Bio monitoring at Fraser Hill and Cameron Highland, Pahang, Malaysia. The mix-methods of observation surveys are to identify physical attributes such as light intensity, altitudes, temperature, wind velocity and air humidity. Secondly, laboratory tests are to identify heavy metal contamination absorbed by mosses. Based on the findings collected around the trails, a connection between altitude and microclimate could be found. The study finds that as the altitude increases and the temperature decreases, the vegetation becomes more dwarfed. Secondly, results from the analysis at Abu Suradi trail within Fraser Hill and Brinchang Trail within Cameron Highland have a higher average of aluminium and iron concentration. Mosses were manifested as good key indicators of air pollution with heavy metals to Malaysia highland forest ecosystems. It showed differential accumulation of heavy metals located near sources of pollution. Thus, the moss data confirms the persistence of risk of pollution of highland forest ecosystems in Malaysia, which demands environmental management. Furthermore, decision makers, planners and designers around the region can evaluate and improve their local strategies related to Tropical Montane Cloud Forest (TMCF) conservation and preservation, especially highlands such as Fraser Hill and Cameron Highland.

Measurement Report: Impact of African Aerosol Particles on Cloud Evolution in a Tropical Montane Cloud Forest in the Caribbean

African aerosol particles, traveling thousands of kilometers before reaching the Americas and the Caribbean, directly scatter and absorb solar radiation and indirectly impact climate by serving as cloud condensation nuclei (CCN) or ice nuclei (IN) that form clouds. These particles can also affect the water budget by altering precipitation patterns that subsequently affect ecosystems. As part of the NSF-funded Luquillo Critical Zone Observatory, field campaigns were conducted during the summers of 2013, 2014, and 2015 at Pico del Este, a site in a tropical montane cloud forest on the Caribbean island of Puerto Rico. Cloud microphysical properties, which included liquid water content, droplet number concentration, and droplet size, were measured. Using products from models and satellites, as well as in-situ measurements of aerosol optical properties, periods of high and low dust influence were identified. The results from this study suggest that meteorology and air mass history have a more important effect on cloud processes than aerosols transported from Africa. In contrast, air masses that arrived after passing over the inhabited islands to the southeast led to clouds with much higher droplet concentrations, presumably due to aerosols formed from anthropogenic emissions.

A new spider genus (Araneae: Linyphiidae: Erigoninae) from a tropical montane cloud forest of Mexico

A new genus and species of spider (Araneae, Linyphiidae, Erigoninae) from a tropical montane cloud forest of Mexico is described from both male and female specimens, Xim trenzado gen. et sp. nov. A phylogenetic parsimony analysis situates Xim gen. nov. as a distinct genus among the distal Erigoninae. Xim gen. nov. is sister to a clade including Ceratinopsis, Tutaibo and Sphecozone, but differs from those genera by having a high cymbium, large paracymbium, short straight embolus, male cheliceral stridulatory striae widely and evenly spaced, both sexes with a post-ocular lobe, male with two series of prolateral macrosetae on femur I, and the female by having strongly oblong, u-shaped spermathecae.