Fire in the tropical gallery forests of Belize

ABSTRACT. Historical records of burning, field observations, and a manipulation experiment were used to evaluate the extent and impact of fire in a system of gallery forests in the Mountain Pine Ridge savanna, Belize. The outer boundaries of gallery forests are fire-prone zones, but fires rarely intrude into these forests. This is attributed to the existence of fire-tolerant trees in the outer zone, which preserve a forest interior of low flammability. Occasional fire incursions are patchily distributed and partially inhibited by slope convexities. Intrusions consume litter and root mats and destroy seedlings and saplings, but create a wide variety of subsequent light regimes depending upon the degree of canopy destruction. At most sites, partial canopy cover persists and seedlings of a subset of forest tree species establish preferentially. Early survivorship of these seedlings is comparable to those established in undamaged forest. Where canopy opening is severe, a secondary succession is initiated, with large numbers of herbaceous plants deriving from the seed bank. Gallery forests contain core zones into which fire very rarely intrudes, and peripheral zones that experience fire incursions that are patchily distributed in space and time. In the latter zones fire incursions play a role comparable to that of canopy gaps in continuous forests, but also create a unique class of micro-habitats to which a subset of tree species is specialized. The fire regime over the recent past in this gallery forest system appears to have had an enriching, rather than a depauperizing, effect on the forest communities, and such systems represent plausible refugia for forest species in fire-prone landscapes.     

A morphometric analysis of Daniellia (Fabaceae – Caesalpinioideae)

A multivariate morphometric study of Daniellia, an endemic genus of tropical and subtropical Africa, indicates that nine species may be recognized: D. alsteeniana, D. klainei, D. oblonga, D. ogea, D. oliveri, D. pilosa, D. pynaertii, D. soyauxii and D. thurifera. In our study we found that some characters, not previously studied in detail, were significant in species delimitation: petiole indumentum, petiole width, number and position of glands on the lower surface of the leaflets and presence or absence of glands at the insertion of each pair of leaflets. The rare and scattered material of D. pilosa and D. soyauxii made their classification uncertain, although some qualitative characters support their differentiation. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 268–279.     

The structure of a polysaccharide isolated from Inonotus levis P. Karst. mushroom (Heterobasidiomycetes)

Inonotus levis biomass was extracted with 5% NaOH containing NaBH₄, the insoluble material was discarded and the solution dialyzed. It was further treated with proteinase and the polymeric fraction isolated by gel chromatography. It contained mostly a polysaccharide of the following structure:

β-GlcA-(1→2)--Gal-(1→6)--Gal3OMe-(1→[→6)--Gal-(1→6)--Gal3OMe-(1→]_5–10

where a non-reducing terminal glucuronic acid residue was present in about half of the molecules, making thus some of the chains acidic and others neutral. Methyl groups were present at about half of the galactose residues, however, no direct proof of the presence of defined repeating units was obtained due to NMR signals overlap. We believe that these short polymeric chains might be originally attached to a protein via serine or threonine residues and were cleaved off due to the alkaline conditions of extraction. Another polymer, co-extracted with this galactan, was a branched phosphorylated mannan with a structure similar to that of the mannan from Saccharomyces cerevisiae yeast.     

Rapid and simple preparation of mushroom DNA directly from colonies and fruiting bodies for PCR

We have optimized a simple and rapid preparation procedure for mushroom DNA extraction from colonies on media or from fruiting bodies for PCR amplification. The protocol combines microwaving twice for 1 min, cooling for 10 min, and centrifuging for 5 min. By using this procedure, more than 100 samples of mushroom DNA can be prepared within 1 h. The DNA obtained can be used for (1) identifying mushroom species by PCR and subsequent sequencing, (2) amplifying low copy number genes (at least 2,000 bp), and (3) screening genetic transformants. This technique will contribute to the mycology of mushroom species.     

Corticioid fungi from the Kimberley Region,Western Australia

Summary  Corticioid fungi from the Kimberley Region of Western Australia are reviewed. 31 species are reported, of which five, Aleurodiscus kimberleyanus, Athelopsis vesicularis, Dendrothele cornivesiculosa, Hyphoderma tubulicystidium, and Phanerochaete subcrassispora are described as new. Grandinia glauca is given the new combination Grammothele glauca, and Hydnum investiens the new combination Phanerochaete investiens. A further eight species are recorded which have not previously been reported from Australia.     

Cockscomb Revisited: Jaguar Diet in the Cockscomb Basin Wildlife Sanctuary,Belize1

The Cockscomb Basin Wildlife Sanctuary, Belize was established in 1986 following Rabinowitz and Nottingham's 1986 study on jaguar diet and distribution. In 2002, we reexamined jaguar diet following two decades of mitigated human hunting of jaguar prey. We observed high overlap between historical and current jaguar diet constructs. Nine‐banded armadillo remained the most frequently consumed prey item. However, collared peccary consumption increased by nearly 20 percent while dietary breadth decreased by 60 percent presumably reflecting increased prey availability following reduced human hunting pressure.     

Beta‐Diversity of Termite Assemblages Among Primary French Guiana Rain Forests

Termites are an important component of tropical rain forests, and have been included in many studies focusing on the influence of human disturbance. Their distribution among primary rain forest has, however, rarely been investigated. Here we studied the termite fauna in seven mostly undisturbed forest sites, representing several rain forest types. Overall, approximately 70 percent of species were soil‐feeders and 25 percent were wood‐feeders, the remaining 5 percent being classified here as litter‐feeders. Termite species richness did not differ significantly among sites, but sites differed in termite abundance. The palm swamp and the low forest situated on the foothills of an inselberg, hosted different termite communities to the other sites. These two sites presented a singular physiognomy suggesting that forest type is an important factor influencing species composition. We found no correlation between termite species composition and distance between sites, highlighting that at the scale of our study (about 100 km), forest sites share a similar species pool.     

Plant biodiversity of two tropical dry evergreen forests in the Pondicherry region of South India and the role of belief systems in their conservation

Natural vegetation on the south-eastern coast of Peninsular India has now been reduced to patches, some of which are preserved as sacred groves. The plant biodiversity and population structure of woody plants (>20 cm girth at breast height; gbh) in two such groves, Oorani and Olagapuram, occurring on the north-west of Pondicherry have been analyzed. A total of 169 angiosperms have been enumerated from both sites. The Oorani grove (3.2 ha) had 74 flowering plant species distributed in 71 genera and 41 families; 30 of them are woody species, 8 are lianas and 4 are parasites. The Olagapuram grove (2.8 ha) was more species-rich with 136 species in 121 genera of 58 families; woody species were fewer (21) while 9 lianas and 3 parasites occurred. The vegetation structure indicates that the Oorani grove is a relic of tropical dry evergreen forest, whereas Olagapuram is reduced to a thorny woodland. The latter is heavily degraded as it has lost the status of a sacred grove because of its conversion to Eucalyptus plantations. The Oorani grove has an Amman temple in the centre. The attendant cultural rites and religious rituals have perpetuated the status of a sacred grove which has ensured the protection of the grove.     

A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures

Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groups—invertebrates, ‘herptiles’ (reptiles and amphibians), mammals and birds—respond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, and—within birds and mammals—between habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species.     

Deforestation in Lacandonia (southeast Mexico): evidence for the declaration of the northernmost tropical hot-spot

To assess the conservation status of Lacandonia, a megadiversity area in Mexico, rates of deforestation were calculated for the periods 1974–1981 and 1981–1991, using a random sample of 38 5 × 5km sites. We evaluated: (i) the overall magnitude of, and spatial and temporal variation in deforestation; (ii) how spatial variation relates to human population density, terrain slope and the presence of the Montes Azules Biosphere Reserve; (iii) the magnitude of potential plant species loss associated with deforestation. Overall deforestation was greater in the former than in the second period (1412 vs. 744ha/year), although mean rates (2.1 and 1.6%/year) were statistically indistinguishable due to a considerable spatial variation. The greatest spatial variation was related to the presence of the Montes Azules Reserve: deforestation outside the reserve was 20 and 6 times greater in the first and second period, respectively. Population density and terrain slope were related to deforestation but the relationship was considerably poor. Estimates of plant species committed to extinction (out of the expected total flora of 4314 species) were as high as 22% by year 2035, and 55% by year 2135. Such levels of potential species extinction associated to deforestation, and the great biological diversity of Lacandonia provide evidence to declare it as the northernmost tropical hot-spot and a priority goal in conservation efforts.     

Identifying forest‐obligate birds in tropical moist cloud forest of Andean Ecuador

ABSTRACT Large‐scale transformation of forested landscapes is a major factor in loss of biological diversity in the American tropics. Investigators examining the responses of species to deforestation rarely control for variation in the amount of forest relative to other habitats at the landscape‐level. Bellavista Reserve on the western slope of the Andes in Ecuador is located between similar‐sized areas of pristine, protected forest, and deforested landscapes. We used strip‐transect counts and mist netting to evaluate habitat use by passerine birds in a habitat mosaic consisting of abandoned pastures, forest edges, forest fragments, and large blocks of interior tropical montane cloud forest (TMCF). During 3600 net hours, we had 1476 captures, including 346 recaptures. Of 78 species captured in mist nets, 30 had sufficient counts for Poison Rate Regression (PRR) modeling (a statistical method for comparing counts). Twelve species (40%) had capture patterns indicative of an affinity for mature TMCF, and 6 species (20%) had significantly higher counts in degraded areas (forest edge, forest fragment, and regenerating pastures) than in interior TMCF. The remaining 40% showed no significant bias in detection among habitats. Combined with strip‐count data, our results suggest that about 38% of the 119 species sampled at the Bellavista Reserve occur primarily in mature TMCF, avoiding edges and early second‐growth forest. Populations of these species may be vulnerable to further loss, fragmentation, and degradation of TMCF and, as such, deserve additional study and a place on lists of species of conservation concern.     

Ancient Maya Agroforestry Echoing Through Spatial Relationships in the Extant Forest of NW Belize

Previous research has shown that ancient Maya ‘forest gardens’—tree‐dominated home gardens containing a diversity of tree species used for daily household needs—still resonate in the species composition of the modern forest. Centuries of positive interspecies interactions may enhance the reproductive and survival success of garden species selected and encouraged by experienced Maya forest gardeners. We hypothesized that such interaction may result in aggregated spatial patterns between 32 pre‐selected, commonly utilized forest garden species. In this paper, we developed a novel randomization (Monte Carlo) method designed to measure and test if the spatial relationships among pairs of Maya ‘forest garden’ trees species differ between areas that experienced high and low ancient settlement density in northwestern Belize. A total of 28 high ancient settlement density and 27 low ancient settlement density plots containing a total of 2772 and 3134 trees, respectively, were used for this study. The analysis revealed that 58 pairs of forest garden species tended to ‘cluster’ together significantly more often in the high settlement density areas than would be expected in a random distribution. In low settlement density plots, only 12 pairs of species exhibited a significant clustered spatial relationship. The effect was not species specific, suggesting that some synergistic relationships, mediated by third‐party agents such as dispersers, may occur at the community level. The impacts of ancient human land use, echoing across centuries of dispersal, colonization, disturbance, and biotic and abiotic interactions, can have important implications for understanding the current biodiversity patterns and processes.     

Recovery of amphibian,reptile, bird and mammal diversity during secondary forest succession in the tropics

In tropical regions, many studies have focused on how vegetation and ecosystem processes recover following the abandonment of anthropogenic activities, but less attention has been given to the recovery patterns of vertebrates. Here we conduct a meta‐analysis (n = 147 studies) of amphibian, reptile, bird and mammal recovery during tropical secondary forest succession (i.e. natural regeneration). For each taxonomic group, we compared changes in species richness and compositional similarity during natural secondary succession to reference forests (mature or old growth forest). In addition, we evaluated the response of forest specialists and the change in bird and mammal functional groups during natural secondary succession in the tropical moist forest biome. Overall, species richness of all groups reached levels of the reference forests during natural secondary succession, but this was not the case for species compositional similarity. The delay in recovery of forest specialists may be the reason for the delay in recovery of species compositional similarity. Overall, vertebrate recovery increased with successional stage, but other potential predictors of diversity recovery, such as, the geographical setting (amphibian and reptile species compositional similarity recovered more rapidly on islands), rainfall (mammal species richness and compositional similarity recovered faster in regions of low rainfall), and the landscape context (amphibian, reptile and mammal species compositional similarity recovered faster in regions with more forest patches) influenced vertebrate recovery. These results demonstrate the important role of secondary forests in providing habitat for many vertebrates, but the slow recovery of species compositional similarity, forest specialists and some functional groups (e.g. insectivorous birds) highlighted the challenge of secondary forest persistence, and strongly argues for the continued protection of old growth/mature forest as habitat for forest specialists and as sources for secondary forest sites.     

Understory Colonization of Eucalyptus Plantations in Hawaii in Relation to Light and Nutrient Levels

Exotic tree plantations may serve as catalysts for native forest regeneration in agriculturally degraded landscapes. In 2001, we evaluated plant species regeneration in the understory of a 7‐year‐old experimental Eucalyptus saligna forest in Hawaii approximately 1 year after the cessation of 5 years of herbicide. These forests were organized in a 2 × 2–factorial design of planting density (1 × 1– or 3 × 3–m spacing) and fertilization (unfertilized control and regular fertilization), which resulted in varying resource availabilities. We found that understory biomass was highest under high light conditions, regardless of fertilization treatment, whereas species richness was lowest under fertilized 1 × 1–m plots. The understory was dominated by species exotic to Hawaii. The most common tree species, the noxious weed Citharexylum caudatum, was particularly successful because high light–saturated photosynthesis rates and a low light compensation point allowed for high growth and survival under both light conditions. To assess longer‐term recruitment patterns, we resurveyed a portion of this site in 2006 and also surveyed five Eucalyptus plantations in this region of Hawaii that differed in age (5–23 years), species (E. saligna, E. grandis, E. cloeziana, E. microcorys), and management (experimental, industrial, nonindustrial stewardship); all were established on previous agricultural sites within approximately 3 km of native‐dominated forest. Again, very few native species were present in any of the stands, indicating that within certain landscapes and for native species with certain life history traits, exotic plantations may be ineffective nursery ecosystems for the regeneration of native species.     

The effect of forest disturbance on the leaf litter ant fauna in Ghana

In order to observe the effect of forest loss on the leaf litter ant fauna in Ghana, West Africa, samples were taken in primary forest, secondary forest and in cocoa plots. Ants were extracted from the leaf litter by sieving followed by suspension in Winkler bags. The species composition and species richness in the three different habitats were compared and no significant difference was found between them. It was concluded that most primary forest leaf litter ant species continue to survive in parts of the agricultural landscape which has largely replaced their original habitat.     

Checklist of the Caesalpinioideae (Leguminosae) of Equatorial Guinea (Annobón, Bioko and Río Muni)

This study provides a checklist of the Caesalpinioideae (Leguminosae) present in Equatorial Guinea, comprising 52 genera and 124 taxa. Seven species are known from Annobón, 33 from Bioko and 109 from Río Muni. The best represented genus is Senna with eight species. In addition, bibliographic references for Caesalpinioideae (Leguminosae) from Equatorial Guinea have been gathered and checked. Fourteen species are included based on literature records, because their distribution ranges suggest they may occur in Equatorial Guinea, 11 introduced species could be naturalized, and 45 taxa are recorded for the first time from the country. This represents an increase of over 35% in the floristic knowledge of Caesalpinioideae from Equatorial Guinea. A statistical summary is presented at the end of the checklist.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 541–562.     

Rediscovery of Leptopanchax splendens (Cyprinodontiformes: Aplocheilidae): a seasonal killifish from the Atlantic Forest of south-eastern Brazil that was recently considered extinct

A recent collection of the seasonal killifish found Leptopanchax splendens c. 5 km from the type locality, 74 years after its last record. The species was historically common in its type locality, the Estrela River basin in south-eastern Brazil, until 1950, after which it was not encountered and thought to have become extinct due to widespread deforestation and urbanization in the region. Despite the rediscovery, this study finds that other recently published reports of L. splendens are misidentifications.