Annotated checklist of Hongkong lichens

An annotated checklist of the lichens of Hong Kong, based on all available literature reports and specimens, including those recently collected by the authors, is presented. In total, 261 species are reported, of which 176 are new records for Hong Kong, 132 of which are new for China, 43 are new for East Asia, and 27 are new for Asia. The lichen vegetation is mainly tropical, as is shown by the distribution patterns of the identified species: 53 species are cosmopolitan, 40 northern temperate, 122 pantropical, 17 paleotropical and 29 endemic to tropical East Asia. With regard to substrata, 129 species are corticolous, 148 saxicolous, 17 foliicolous and 19 terricolous. Four species are newly described: Anisomeridium conorostratum Aptroot, A. hydei Aptroot, Caloplaca pulicarioides Aptroot and Placidiopsis poronioides Aptroot. The flora is rather poor in species; for example, no Caliciales have been found. In the past, the numbers of species of several groups such as the Graphidaceae, Heterodermia and Xanthoparmelia have been overestimated, whereas few pyrenocarps have been reported. The flora of wet granitic outcrops is surprisingly well developed in Hong Kong. Although not a single Peltula species was reported before, six species were identified, including one that was previously only known from Africa. In addition, several other cyanophilic genera are present, such as Euopsis, Psorotichia, Pyrenopsis and, most unexpectedly, Vestergrenopsis, each with one species. A comparison between old and recent records shows that many Lobarion species are now extinct. The drastic decline of species of the Lobarion vegetation indicates that air pollution and other habitat disturbances, mainly deforestation, to which these species are very sensitive, are seriously threatening the lichen biodiversity of Hong Kong

The lichen flora of the Chagos Archipelago : including a comparison with other island and coastal tropical floras

The 1996 Chagos Expedition provided the first opportunity to study the archipelago’s lichen flora. Seventeen of the 55 islands were ecologically investigated, some in more detail than others, and lists and representative collections of lichens have been assembled for many of them. In all, 67 taxa have been recorded, 52 to specific level. Although the islands have a low biodiversity for cryptogamic plants, as would be expected in terms of their relatively young age, remoteness and small terrestrial surface areas, those taxa that are present are often found in abundance and play significant ecological roles. There is a good correlation between total lichen biodiversity and island size, despite the fact that Cocos nucifera is such an important substratum for cryptogamic plants and its presence on all islands studied provides a consistently high associated species count. Comparisons of lichen floras for ten island and coastal tropical areas show good correlations (based on the Sörensen Coefficient) within the Indian Ocean as would be expected, but poorer correlations exist within and between Pacific Ocean and neotropical floras. Ranked correlations between Chagos and other floras are in the sequence Maldives > Laing Island > Aldabra > Tuamotu > Pitcairn > N.Mariana & Belize > Guadeloupe > Cook. When coefficients are calculated using only the Physciaceae, different correlations and sequences are derived, but the affinities of the Indian Ocean islands remain strong. However, although the lichen flora of Chagos is characteristic for an Indian Ocean, it is dominated by pantropical species

Tree biomass equations from terrestrial LiDAR : a case study in Guyana

Large uncertainties in tree and forest carbon estimates weaken national efforts to accurately estimate aboveground biomass (AGB) for their national monitoring, measurement, reporting and verification system. Allometric equations to estimate biomass have improved, but remain limited. They rely on destructive sampling; large trees are under-represented in the data used to create them; and they cannot always be applied to different regions. These factors lead to uncertainties and systematic errors in biomass estimations. We developed allometric models to estimate tree AGB in Guyana. These models were based on tree attributes (diameter, height, crown diameter) obtained from terrestrial laser scanning (TLS) point clouds from 72 tropical trees and wood density. We validated our methods and models with data from 26 additional destructively harvested trees. We found that our best TLS-derived allometric models included crown diameter, provided more accurate AGB estimates (R-2 = 0.92-0.93) than traditional pantropical models (R-2 = 0.85-0.89), and were especially accurate for large trees (diameter > 70 cm). The assessed pantropical models underestimated AGB by 4 to 13%. Nevertheless, one pantropical model (Chave et al. 2005 without height) consistently performed best among the pantropical models tested (R-2 = 0.89) and predicted AGB accurately across all size classes-which but for this could not be known without destructive or TLS-derived validation data. Our methods also demonstrate that tree height is difficult to measure in situ, and the inclusion of height in allometric models consistently worsened AGB estimates. We determined that TLS-derived AGB estimates were unbiased. Our approach advances methods to be able to develop, test, and choose allometric models without the need to harvest trees

New records and additions to the hepatic flora of Uganda 2

82 liverwort taxa are recorded from Uganda, of which 24 are new to the flora of the country. Colura hedbergiana, Colura kilimanjarica and Harpalejeunea fischeri found on Mt. Elgon, were previously known only from their type locality on Mt. Kilimanjaro or on Mt. Karisimbi. A Madagascan-Mascarene species, Plagiochila boryana was also found on Mt. Elgon. Its only known previous locality in continental Africa was Mt. Kilimanjaro

New lichens and lichen records from Papua New Guinea : with the description of Crustospathula, a new genus in the Bacidiaceae

Several lichen species are reported from the first time from New Guinea, based on material collected by the author in 1995. The following new taxa are described: Crustospathula cartilaginea gen. et spec. nov., Pseudopyrenula serusiauxii spec. nov. and Trypethelium galligenum spec. nov. Psoroma papuana Aptroot & Diederich nom. nov. is proposed as new name for Psoroma pannarioides Aptroot & Diederich

Height-diameter allometry of tropical forest trees

Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were: 1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap). 2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A). 3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass. Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike\u27s information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account

Hepaticae of Cerro Venamo, Venezuela, collected by J. Steyermark

A revision of herbarium material (NY) from Cerro Venamo, Venezuela (5°59’ N, 61°23’ W, 1890 m) yielded 77 hepatic species in 44 genera and 13 families. Most species have a neotropical distribution (75,32%), 6,49%, are pantropical and 9,09% are reported only from the tepuis

A small collection of bryophytes from Montserrat, West Indies

Four species of liverworts and 13 taxa of mosses have been identified from samples collected in Montserrat in 1980, 11 of which appear to be new to the island