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The diversity of cultivated plants in the agroforestry systems can create conditions to maintain the vital edaphic processes similar to natural regeneration areas. We studied agroforestry systems with five (AF5) and ten years (AF10) of age in comparison with natural regeneration areas for 10 years (NR) in the Atlantic Forest Biome in an area of environmental fragility. The microbial biomass carbon (MB-C), soil basal respiration (BResp), metabolic quotient (q-CO 2 ) and microbial quotient (q-mic) were evaluated in the entire profile of a Typic Udorthents, obtaining stratified data in the 0-2.5; 2.5-5; 5-10; 10-15; 15-30; 30-45 and 45-60 cm layers. The NR area had the highest MB-C (866 mg C kg -1 soil) and BResp (5 mg C-CO 2 kg -1 soil h -1 ) in the 0-2.5 cm layer in relation to the AF5 (686 mg C kg -1 soil; 4 mg C-CO 2 kg -1 soil h -1 ) and AF10 (478 mg C kg -1 soil; 4 mg C-CO 2 kg -1 soil h -1 ). However, the ratios did not differ among treatments, presenting average values in the profile of 7 mg C-CO 2 g -1 MB-C h -1 for q-CO 2 and 1.6 % for q-mic, demonstrating vital process similarity between systems. The phytosociological characteristics that interfere with the microbiological attributes were the plant species richness (0-2.5 cm) and plant diversity (2.5-5 cm). The epiedaphic fauna active in the litter was also assessed by pitfall traps and the average number of individuals per trap (238 for NR, 281 for AF5, 299 for AF10), the order richness (15 for NR; 14 for AF5, 13 for AF10) and relative frequencies did not differ among treatments, confirming that agroforests are in an ecosystem self-regulation condition function similar to natural regeneration, even with the removal of food products and income generation for the farmers.

Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m 2 (hot), respectively, with a maximum of 44.000 ind./ m 2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.Keywords: Enchytraeidae, Oligochaeta, extraction methods, Araucaria, subtropical. Abundância de enquitreídeos na Floresta Ombrófila Mista determinada por extração úmida quente e fria ResumoOs enquitreídeos são pequenos oligoquetas encontrados no mundo todo em solos com suficiente umidade e matéria orgânica, porém muito pouco estudados no hemisfério Sul. Este é o terceiro estudo sobre a abundância de enquitreídeos no Brasil utilizando o método de extração úmida e o primeiro realizado em Floresta Ombrófila Mista (região subtropical).A amostragem e extração foram baseadas no método padrão ISO 23611-3/2007, utilizando-se um trado desmontável adaptado e extração úmida com e sem aquecimento para acessar a abundância de enquitreídeo em um fragmento de floresta na Embrapa Florestas em Colombo, Paraná. As amostragens foram realizadas em três ocasiões entre setembro, 2011 e abril 2012. Os números médios estimados através de cada método variaram de 2.000-12.000 (frio) e 5.000-12.000 ind./ m 2 (quente), respectivamente, e o máximo de 44.000 ind./ m 2 em uma das amostras, o mais alto já relatado no Brasil. A extração quente foi a mais vantajosa, considerando a rapidez e preservação dos exemplares in vivo. As vantagens e desvantagens das extrações úmidas comparadas aos métodos de triagem manual e extração com formol foram discutidas. Os gêneros Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia e Achaeta foram identificados nas amostras.Palaras-chave: Enchytraeidae, Oligochaeta, métodos de extração, Araucária, subtropical.

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Palavras-chave adicionais: apoplasto; aquisição de nutrientes; concentração de nutrientes; forrageira. AbstractThe cation exchange capacity of root (CECr) occur, mainly on the cell wall, and affect the nutrients uptake by plants. However, there is few researches evaluating the CECr in plants with nutritional deficiency. Thereby, the aim this work was (I) asses the influence of nutritional deficiency on the CECr, and (II) to research the between the nutritional status of oat and CECr. For this, the plants were cultivated during50 days with nutrient solutions with deficiency of Ca, Mg, P and Mn, control solution containing all nutrients. After the period of growing was determined the CECr, the dry matter, the nutrients content and the accumulation in shoot. The deficiency of Ca, Mg, P and Mn reduced dry matter, increased the CECr and affected the nutritional status of oat cultivated in nutritional solution. The CECr was correlate with the concentration of K and Cu in the shoot of oat.