Assessment of woody plant species composition in secondary deciduous forests of Odisha, India

Plant species composition according to their functional types, distribution pattern are crucial for biodiversity conservation in tropical deciduous forest. The study assessed the woody plant species diversity, stand structure and population density in the secondary deciduous forest of Chandaka wildlife sanctuary, Odisha, India. A total of 70 species belonging to 63 genera and families were documented in this study.The stem density was found to be 1080 stems/ha with reverse J-shaped population structure indicating good regeneration potential of the forests. Shannon diversity Index varied from 0 to 2.31 whereas Simpson's index varied from 0 to 0.85. The correlation study between Importance Value Index and basal area were significant (p=40.63). The present study would be helpful for conservation and management of biodiversity in secondary dry deciduous forests of Chandaka Wildlife Sanctury in particular and tropical dry forests in general.

A Synopsis of Croton (Euphorbiaceae) in Michoacán, Mexico

A taxonomic and nomenclatural review of the genus Croton (Euphorbiaceae) in the Mexican state of Michoacán is presented. Six sections and 20 species are here reported. The greatest diversity is in the Balsas Depression province, where at least 12 species occur. There is a strong tendency to thrive in tropical deciduous forest. An identification key is provided, and for each species, the following information is included: protologue citation, type information, habit, habitat, and elevation within the state, regional and global distribution, and phenology. Relevant synonyms are listed, as too are herbarium specimens. Lectotypes are designated for Croton draco, C. niveus, and C. calvescens. One species, Croton rojasii, is described as new and illustrated with photos. It is known only from tropical deciduous forest in the Zicuirán-Infiernillo Biosphere Reserve, at elevations from 400 to 700 m. It belongs to sect. Geiseleria and is remarkable because of the strongly unequal pistillate sepals, the larger of which becoming accrescent and exceeding the fruit.

The effects of Heavy Metals on Microbial Biomass of Forest Soil from Tropical Deciduous Forest of Central Ganga Plain

This investigation was aimed toward assessing the impact of heavy metals on soil microbial cycles. The impacts of lead (Pb) and cadmium (Cd) at various concentrations were researched over a time of about two months. Chloride salts of Pb and Cd were added independently and in blend to soil samples at room temperature (27ºC) in various polythene packs. Samples were taken from the sacks at about fourteen days span and estimations were taken of the microbial biomass carbon (MBC). The outcomes showed that there was a significant reduction in the microbial biomass carbon for all treated soils from the second week to the 6th week. However, on 8th week, increase in microbial biomass carbon was observed. At the 6th week, 2000mgkg-1Pb and 40mgkg-1Cd gave the main reduction (P < 0.05) in microbial biomass carbon of 98%. A critical decrease in biomass carbon in metal contaminated soil demonstrated that this parameter is a decent marker of toxicity of metals on soil microflora.

First record of Neurosystasis Satchell in Mexico, with the description of one new species (Diptera, Psychodidae), and the validation of Chuspilepia Omad, Mangudo & Gleiser as subgenus

Neurosystasis Satchell is newly recorded in Mexico by means of the description of a new species. Specimens captured in a tropical deciduous forest in southern Puebla, central Mexico, were examined and determined as a species new to science. The male and female are described based on morphological characteristics. Neurosystasis longistylis sp. nov. is similar in appearance to Neurosystasis saltenia (Omad, Mangudo & Gleiser, 2015), but is readily distinguished based on characters of the head, wing, and male genitalia. In both species, R2+3 is attached to vein R4, the wing membrane is infuscate with dark spots on vein apices, and lacks sensory organs near the apex of Sc, characters not present in other species of Neurosystasis, and for that reasons we proposed the recovery of Chuspilepia from its synonym and validate it as a subgenus of Neurosystasis to include both continental species.

Taxonomic and Functional Diversity of Aquatic Macroinvertebrate Assemblages and Water Quality in Rivers of the Dry Tropics of Costa Rica

One of Costa Rica’s driest areas is the province of Guanacaste, in the Pacific Northwest, with almost no rain during the dry season from November to April. Due to this marked seasonality, the area is covered by dry tropical deciduous forest, considered the most threatened and least known tropical ecosystem in this area. This study analyzes and characterizes the assemblages of aquatic macroinvertebrates in water bodies within the Tempisque basin. Biological water quality was measured using the BMWP′-CR index. Macroinvertebrate assemblages were analyzed using abundance, richness, and functional feeding group approaches (FFG). Partial least square (PLS) analyses were performed, and the relationships between environmental factors and macroinvertebrate assemblages are also discussed. Macroinvertebrate assemblages were dominated numerically by mayflies, caddisflies, flies, and beetles. The BWMP′-CR index showed varying biological water quality, ranging from “very bad” to “excellent,” depending on rainfall and site management. Results suggest that tropical Mesoamerican rivers contradict the “river continuum concept” because predators and scrapers displace shredders in numbers. On the other hand, the study area shows a notable high richness of the Coleoptera genera. The class Rhynchocoela (Nemertea) is reported for the first time in Central America. The results indicate that the dry forest river ecosystem shows staggering biodiversity despite the surrounding agricultural land use, probably because of their older origin concerning tropical rain forests in Central America.

Two new species of nopal (Opuntia, Cactaceae) from the Baja California Peninsula (Mexico)

Two new species of prickly-pear/nopal (Opuntia sierralagunensis and O. caboensis, Cactaceae) are described and illustrated here; both occur in the tropical deciduous forest plant community found in the Cape region of the Baja California Peninsula, Mexico. Previously, these two species had been overlooked and were considered extreme forms of species described from the Sierra de La Giganta (e.g., O. comonduensis, O tapona), located hundreds of kilometers away. However, with an improved collection of specimens and field knowledge of the Opuntia species in the region, we have determined that these prickly-pears are new to science and are restricted to the Cape region. We provide justification to separate them from sympatric congeners and other similar species in the southern peninsula.

Vegetation response to the Indian Summer Monsoon (ISM) variability during the Late-Holocene from the central Indian core monsoon zone

Pollen analysis and radiocarbon dating of a 1.4 m deep lacustrine sediment profile from Chhattisgarh State, central India, in the core monsoon zone (CMZ), has revealed the vegetation history, associated climate change and the Indian Summer Monsoon (ISM) rainfall variability during the Late-Holocene. The pollen evidence suggests that between ca. 3000 and 2600 cal year BP, tree-savannah vegetation occurred in the region having a comparatively lesser monsoon rainfall. The forest expanded and culminated into an open-mixed tropical deciduous forest between ca. 2600 and 2200 cal year BP under a warm and moderately humid climate with an increase in monsoon rainfall. Subsequently, between ca. 2200 and 2000 cal year BP, the existing open-mixed tropical deciduous forest transformed into a mixed tropical deciduous forest under a warm and humid climate with further increase in monsoon rainfall. Finally, between ca. 2000 and 1800 cal year BP, a dense mixed tropical deciduous forest occupied the landscape under a regime of a warm and relatively more humid climate with further strengthening of the ISM. The gradual warming, and the climatic amelioration with the intensification of the ISM, during the Late-Holocene (ca. 2600–1800 cal year BP; ~650 BC to AD150) corresponds to the Roman Warm Period (RWP), recorded globally between 2500 and1600 cal year BP (~550 BC to AD ~350). Human activities were present around the study area, which varied according to the ISM variations. The present study provides insights into the gradual intensification of the monsoon since the last ca. 2600 cal year BP (between ca. 2600 and1800 cal year BP), and an increase in the ISM strength in the CMZ of India, against the generally weakening trend during the Late-Holocene.