The Tropical managed Forests Observatory: a research network addressing the future of tropical logged forests

While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories.     

Evolution of the salmonid mitochondrial control region.

To explore the evolutionary nature of the salmonid mitochondrial DNA (mtDNA) control region (D-loop) and its utility for inferring phylogenies, the entire region was sequenced from all eight species of anadromous Pacific salmon, genus Oncorhynchus; the Atlantic salmon, Salmo salar; and the Arctic grayling, Thymallus arcticus. A comparison of aligned sequences demonstrates that the generally conserved sequence elements that have been previously reported for other vertebrates are maintained in these primitive teleost fishes. Results reveal a significantly nonrandom distribution of nucleotide substitutions, insertions, and deletions that suggests that portions of the salmonid D-loop may be under differential selective constraints and that most of the control region of these fishes may evolve at a rate similar to that of the remainder of their mtDNA genomes. Maximum likelihood and Fitch parsimony analyses of 9 kb of aligned salmonid sequence data give evolutionary trees of identical topology. These results are consistent with previous molecular studies of a limited number of salmonid taxa and with more comprehensive, classical analyses of salmonid evolution. Predictions from these data, based on a molecular clock assumption for the mtDNA control region, are also consistent with fossil evidence that suggests that species of Oncorhynchus could be as old as the Middle Pliocene and would have thus given rise to the extant Pacific salmon prior to about 5 or 6 million years ago.     

Dimorphism, parasitism, and sex revisited: modes of reproduction among deep-sea ceratioid anglerfishes (Teleostei: Lophiiformes)

Sexual parasitism, a remarkable mode of reproduction unique to some members of the deep-sea anglerfish suborder Ceratioidei, in which males are dwarfed and become permanently attached to much larger females, is described in a number of previously unreported specimens and taxa. Although generally attributed to all ceratioids, and despite more than a sevenfold increase in the number of known parasitized females in collections throughout the world in the past 50 years, the phenomenon is surprisingly confined to few taxa within the suborder. To date, permanently attached males have been found in only 5 of the 11 ceratioid families, 10 of the 35 genera, and 23 of the 160 recognized species. Notes on taxonomic content, available material, occurrence of sexual parasitism, gravid females and ripe males, the development of eyes and nostrils of the males, the ability of males to capture and ingest food independently of the female, occurrences of multiple attachments of males to a single female, and the nature of the fusion between coupled males and females are given for each ceratioid family. This information is then summarized and discussed. Evidence is presented to reaffirm the presence of three reproductive modes: obligatory parasitism, facultative parasitism, and temporary nonparasitic attachment. Additional evidence is provided to reaffirm the hypothesis that sexual parasitism has evolved separately at least three and perhaps five or more times within the suborder.     

On the phytosociology and ecology of Isoëtes asiatica (Makino) Makino in oligotrophic water bodies of South Sakhalin

In 1989, in the southeast of the Sakhalin Island and south of the village Okhotskoye, Isoëtes asiatica (Makino) Makino and I. beringensis Kom. were detected in 24 oligotrophic lakes for the first time on Sakhalin. These are stands of the community of Isoëtetum asiaticae ass. nov. which in the majority of the lakes form a characteristic pioneer vegetation of the shallow littoral zones. In addition to poor-species dominance stands of both of the Isoëtes species, penetration stages of both of these species as well as stages rich in Comarum palustre, Eleocharis acicularis and Potamogeton species can be differentiated. Besides the structure of the species, the site conditions, particularly of the water bodies are described. The ion content is represented by absolute and relative ion field diagrams exemplified by 7 selected water bodies. The ion content is characterized by sodium and chloride which are prevailing, while calcium and magnesium as well as hydrogen carbonate and sulphate exist in low quantitative proportions only. The indicator values of individual characteristics and the complex characteristics of the Isoëtes lakes are discussed. The hydrochemical characteristics of the Sakhalin, Kuriles and Kamchatka Isoëtes waters are compared with the Isoëtes water bodies of North America and Europe. The danger to Isoëtes water bodies is discussed, necessary protective measures are defined.     

A pulsed diagonal-beam ultrasonic airflow meter

The construction and specific function of a new ultrasonic flowmeter are described. The mean velocity of the respiratory airflow is calculated by measuring the transit times of short ultrasonic pulse trains, simultaneously transmitted upstream and downstream at a 500-Hz rate. The flowmeter system consists of a control unit and a separate flow head. The former includes the power supplies, a controlling microprocessor, most of the signal-processing circuitry, and three analog outputs for flow, volume, and temperature. The flow head contains the respiratory tube with a constant circular cross section (length 90 mm, diam 20 mm, dead space 35 ml), a fast temperature sensor, two electronic circuits for processing of flow and temperature data, and a sound transmission channel with two capacitive ultrasonic wide-band transducers. This respiratory airflow meter, suitable for spirometric maneuvers (vital capacity, forced vital capacity) as well as for long-term breath-by-breath respiratory analysis, is extremely fast (response time 1-2 ms) and accurate (volume accuracy with room air +/- 0.7%), with low noise (below 9 ml/s), a wide flow range (bidirectional from 0 to 9 l/s), and a flat frequency response up to 70 Hz.