GROWTH OF BARU AND GON\uc7ALO-ALVES SEEDLINGS IN DEGRADED SOIL, SUPPLEMENTED WITH RESIDUE IN ILHA SOLTEIRA-SP STATE

O processo de revegeta\ue7\ue3o representa uma alternativa para recupera\ue7\ue3o de \ue1reas com solo exposto. Este trabalho objetivou avaliar o crescimento de mudas de Dipteryx alata (baru) e Astronium fraxinifolium (gon\ue7alo-alves) em solo degradado, compactado ou n\ue3o, suplementado com res\uedduo agroindustrial e verificar a possibilidade de uso deste como condicionante do solo. O experimento, conduzido na UNESP/Campus de Ilha Solteira, em cultivo protegido, apresenta tr\ueas doses de res\uedduo (0, 15 e 30 t ha-1), duas densidades (1,0 e 1,5 g cm-3) e duas plantas indicadoras (Dipteryx alata e Astronium fraxinifolium). As plantas, arb\uf3reas de cerrado, ocorrem nas proximidades da \ue1rea degradada, onde o solo foi coletado. As mudas foram avaliadas 7 meses ap\uf3s desbaste, para altura, di\ue2metro do caule, n\ufamero de folhas, massa fresca e seca da parte a\ue9rea e do sistema radicular, e o solo foi avaliado para an\ue1lise da fertilidade. Os resultados mostram que o res\uedduo agroindustrial (RA) elevou pH, teores de pot\ue1ssio, c\ue1lcio e magn\ue9sio, e diminuiu o alum\uednio dispon\uedvel. O Dipteryx alata teve a massa fresca da raiz influenciada negativamente pela compacta\ue7\ue3o e se mostrou pouco exigente quanto \ue0 adi\ue7\ue3o de nutrientes pelo RA. O Astronium fraxinifolium teve a massa fresca da raiz e a altura negativamente influenciados pela compacta\ue7\ue3o, enquanto a adi\ue7\ue3o do RA favoreceu altura, di\ue2metro do caule, massa fresca e seca da parte a\ue9rea e do sistema radicular. A morfologia das ra\uedzes foi alterada pela compacta\ue7\ue3o, nas duas esp\ue9cies. O substrato utilizado apresenta elevada capacidade de reorganiza\ue7\ue3o, produzindo elevada densidade sem aplica\ue7\ue3o de for\ue7a.The revegetation process represents an alternative to recovery of areas with exposed soil. The aim of this research was evaluate the growth of Dipteryx alata (baru) and Astronium fraxinifolium (gon\ue7alo-alves) seedlings in degraded soil, compacted and not, supplemented with agro-industrial residue, and verify the possibility of using this as a chemical soil conditioner. The experiment was conducted at UNESP/Ilha Solteira Campus, under protected cultivation, with the following treatments: 3 doses of residue (0, 15 and 30 t ha-1), two densities (1.0 and 1.5 g cm-3) and two indicator plants (Dipteryx alata e Astronium fraxinifolium). The selected plants are arboreal species from \u2018cerrado\u2019 biome, which occur in the vicinity of the degraded area, where the soil was collected. The seedlings were evaluated 7 months after roughing, for height, diameter of stem, number of leaves, fresh and dry weight of shoots and roots, and the soil was evaluated for fertility. The results show that the agro-industrial residue (RA) has increased the pH, potassium, calcium and magnesium, and reduced the exchangeable aluminum. The Dipteryx alata fresh root weight, was negatively influenced by compaction and showed little demanding for nutrients added by RA. Fresh root weight and height of Astronium fraxinifolium were negatively influenced by compaction whereas the addition of agro-industrial residue increased the plant height, stem diameter, fresh and dry weight of shoot and root. The root morphology was affected by compaction, in both species. The used substrate presents a high capacity of particles reorganization, resulting in a high density, without force application

Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage

Biophysical Factors Affecting the Distribution of Demersal Fish around the Head of a Submarine Canyon Off the Bonney Coast, South Australia

We sampled the demersal fish community of the Bonney Canyon, South Australia at depths (100–1,500 m) and locations that are poorly known. Seventy-eight species of demersal fish were obtained from 12 depth-stratified trawls along, and to either side, of the central canyon axis. Distributional patterns in species richness and biomass were highly correlated. Three fish assemblage groupings, characterised by small suites of species with narrow depth distributions, were identified on the shelf, upper slope and mid slope. The assemblage groupings were largely explained by depth (ρw = 0.78). Compared to the depth gradient, canyon-related effects are weak or occur at spatial or temporal scales not sampled in this study. A conceptual physical model displayed features consistent with the depth zonational patterns in fish, and also indicated that canyon upwelling can occur. The depth zonation of the fish assemblage was associated with the depth distribution of water masses in the area. Notably, the mid-slope community (1,000 m) coincided with a layer of Antarctic Intermediate Water, the upper slope community (500 m) resided within the core of the Flinders Current, and the shelf community was located in a well-mixed layer of surface water (<450 m depth)