Deep soil heterogeneity and fine root distribution in forests and pastures of eastern Amazonia

Little is known about deep soil heterogeneity, or its relationship with fine root distribution. Beneath a mature, closed-canopy forest of eastern Amazonia, and the pastures and secondary forests that are derived from this forest, soil soft spots and hollow chambers occur to at least 9 meters depth. We measured the vertical distribution of these soil patches, and compared chemical characteristics, mycorrhizal infection, and root density of soil soft spots with the surrounding matrix of more homogeneous soil. Soil soft spots and chambers varied little with depth, but occupied the greatest soil volume (0.8 to 1.2%) from 4 to 6 m depth in the mature forest. Soft spots had lower pH, P availability and arbuscular mycorrhizal infection, and higher K availability than surrounding soil. Root length density was 2 to 15 times higher in soft spots than in surrounding soil. In the pastures, roots were found only in soil soft spots at depths of >3 m. Pastures and secondary forest had more soil chambers in the upper meter of soil than mature forest, but were otherwise indistinguishable in their patterns of deep soil heterogeneity. Soil soft spots may be vestiges of cutter ant nest chambers, while hollow chambers are cutter ant chambers and root channels. Chambers may act as conduits for root penetration and water penetration to deep soil.Abbreviations AM arbuscular mycorrhizae - RLD root length density (root length per unit of soil volume)     

Divergence between the Anoas of Sulawesi and the Asiatic Water buffaloes, inferred from their complete amino acid sequences of hemoglobin ß chains

Four complete amino acid sequences of hemoglobin β chains were determined for the swamp and the river types of the Asiatic water buffalo (Bubalus bubalis) and two species of the subgenus Anoa in Bubalus; B. (A.) depressicornis (H. Smith, 1827), the lowland anoa, and B. (A.) quarlesi (Ouwens, 1910), the mountain anoa. The two types of the bubalis were identical in the 145 amino acid residues of the β chains and, compared to this sequence, the two residues were substituted in the depressicornis (β49Thr → Ser and 134Ala → Thr) and the five were in the quarlesi (β53Val → Ile, 74Met → Ile, 111Val → Ile, 115Arg → His and 134Ala → Thr). While both Anoa species diverged from the bubalis by the β134Ala → Thr, they differed from each other by the five substitutions. The Anoa species are endemic to Sulawesi of Indonesia. Their speciation and the present coexistence were discussed with reference to probable immigrations of two ancestral Anoa species to Sulawesi at so long interval that had caused a reproductive isolation between the two wild animals. The earlier immigrants were postulated to be ancestral to the quarlesi and the later ones to the depressicornis.     

Intertidal interstitial Halicyclops from the Brazilian coast (Copepoda: Cyclopoida)

H. tageae sp. n. and Halicyclops ytororoma sp. n. are described from the intertidal interstitial water of Brazilian beaches. H. tageae is distinguished from all congeneric species by the number of setae on legs 1–4 endopodite 2 (1, 1, 2, 2) and by possessing a reduced inner spine on the leg 5 exopodite. It shares with H. brevispinosus, H. pusillus and H. canui the spine formula 2, 3, 3, 3 on exopodite 3 of swimming legs 1–4. H. ytororoma closely resembles H. gauldi and differs from this species by having 4 setae on leg 1 endopodite 3; H. gauldi has 3 setae on this segment.This is the first record of Halicyclops from marine interstitial water in Brazil.     

Biogeography of the octocorallian coelenterate fauna of southern Africa

The geographical and bathymetric distribution of southern African octocorals is analysed. Of the over 200 estimated species of regional octocorals, 81 confirmed and adequately described species are studied using a radial sector method. Two primary faunal components are recognized–endemic (53.3% of the fauna by numbers of species) and Indo-Pacific (39.4%). An Atlantic component contributes only minimally (about 1.7%), while the remaining fauna is made up of cosmopolites (2.8%) and scattered species (2.8%). A subantarctic component is not evident for the present-day, although evidence for previous contact is presented. A sister-group analysis using genera as a guide to sister species, shows the biogeographic affinities for the present-day fauna as a whole to be 45% Indo-Pacific, 31% cosmopolitan, 10% endemic, 10% Atlantic and 4% southern oceans (subantarctic). Applying the same method to only those genera with endemic species shows the affinities of the present-day endemic fauna to be 27.5% Indo-Pacific, 27.5% endemic, 24% cosmopolitan, 14% Atlantic and 7% subantarctic. Clearly defined boundaries for west, south, and east coast faunas (as recognized by previous authors in describing various intertidal faunas) are found not be present with regard to the octocoral fauna (largely due to its overwhelmingly subtidal nature). Instead two primary zoogeographic provinces are recognized–the Cape Endemic Province (extending from Liideritz to Inhaca Island) and the south-western fringe of the Indo-Pacific Province from East London north-eastwards. An overlap zone between these two is recognized between East London and Inhaca Island, with the region in the vicinity of Richards Bay having an essentially evenly mixed fauna (roughly 50% Cape Endemic Province and 50% Indo-Pacific). Of the 84 octocoral genera recorded for the region, seven (or 8.3%) are endemic, and of these, five are monotypic while two are ditypic. The fauna is shown to be predominantly sublittoral (about 95% by numbers of species), the shallow sublittoral (< 100 m in depth) being the region with highest species richness. Pennatulaceans are eurybathic (intertidal to 4756 m) and clearly show a high proportion of cosmopolites (20% of presently identified species). Soft corals are stenobathic and restricted to the intertidal, continental shelf and uppermost portion of the continental slope (<500m), while gorgonians are intermediate in depth distributon (intertidal to 1200 m). No cosmopolitan alcyonaceans are presently recorded. The centre of the Cape Endemic Province is the Agulhas Bank–an extensive region of shallow continential shelf (< 200 m in depth) between Cape Town and East London. Two regions of octocoral radiation for southern Africa are postulated–the Agulhas Bank and the western Indian Ocean.     

Cambrian lobopodians–ancestors of extant onychophorans?

This paper is a review of published information on fossil lobopodians, with addition of observations and ideas based on new material. It is also an analysis of the phytogeny of the group, and presents a new classification. A character shared by three or four families, yet not seen before, is a pair of enlarged sclerites covering the head. This forms an argument for re-orienting Hallucigenia once again. This genus no longer being enigmatic, a corner-stone in Stephen Jay Gould's evidence for extinct phyla is therefore gone. It is suggested that the lobopodians, phylum Lobopodia, are arranged in two classes, the extinct Xenusia for marine forms, and the Onychophora for terrestrial forms. The marine lobopodians are morphologically much more diverse than the extant onychophorans, a condition expressed in the classification. New taxa are: Hallucigenia fortis sp. nov., the families Luolishaniidae, Cardiodictyidae and Onychodictyidae, and the new orders Archonychophora, Scleronychophora and Paronychophora.     

The effects of recreated instream and ecotone structures on the fish fauna of an epipotamal river

Investigations of fifteen sections of seven Austrian epipotamal (barbel region) streams between 1981 and 1984 demonstrate the impact of instream river bed structures on fish communities. Reduced spatial heterogeneity due to river straightening resulted in decreasing species number, diversity, stock density and biomass. Reincreased variability of the river bed in the frame of a subsequent restructuring project improved all community-specific values significantly within a 3-year investigation period (1988–1990). Besides the regained habitat variability in form of riffle pool sequences and other instream structures, the newly created riparian zones obviously provided important niches, e.g. as refuge areas during flooding and as nursery grounds for fish fry. The positive effects of the recreated land/water ecotone are discussed with respect to river restoration projects.     

贵州盘县大洞遗址动物群的研究

本文记述盘县大洞遗址１９９２－９３年发现的哺乳动物化石共计４３种,属于中更新世中,晚期生活在云贵高原和东南亚丘陵地区的过渡地带的动物群,动物群的主要成员为华南地区大熊猫－剑齿象动物群成分的,但也有一些云贵高原的土著种类,它反映一种以亚热带生态以为主,其间有若干次干,凉气候波动的环境。     

Mineralization dynamics in fallow dryland wheat plots,Colorado

Summary There was a flush of mineralization in fallow wheat plots in the wet and warm summer of 1982 at Akron, Colorado. Peak mineralization rates and concentrations of N and P coincided with a 2.5-fold increase in protozoan biomass. No-till contained considerably more activity than stubble mulch plots, especially in the surface 2.5 cm and there was more water storage in no-till on all dates. Differential management of agricultural residues and the resultant effects upon the microbial community significantly altered patterns of nutrient cycling.     

Effects of paper mill effluents on the fish fauna of stony shores of Lake Päijänne

The fish fauna of the stony littoral in the central parts of L. Päijänne was studied by electric fishing on four occasions during 1988–1989. Ten fish species and 1681 individuals (14.5 kg) were caught in the 15 fishing sites (4096 m²) which gives a mean density of 0.41 ind. m^–2 and biomass of 3.5 gm^–2. Effluent from two large paper mills causes a clear zonation of the fish fauna in the area. In the most polluted shores, only burbot and perch occurred regularly and the reproduction of other species was inhibited. In the semipolluted area (5–15 km from the Kaipola paper mill), burbot and stone loach occurred regularly, but owing to low numbers of perch and bullhead the total densities were usually low.The clean shores were characterized by an abundance of stone loach and bullhead and locally also of minnow, which seemed to be very sensitive to pollution. The strong floods during summer 1988 had positive effects on the reproduction of perch and pike, but the densities of other species were highest during the normal water level in autumn 1989.