Soil quality indicators in a rhodic kandiudult under different uses in northern Parana, Brazil.

Sustainable use of soil, maintaining or improving its quality, is one of the goals of diversification in farmlands. From this point of view, bioindicators associated with C, N and P cycling can be used in assessments of land-use effects on soil quality. The aim of this study was to investigate chemical, microbiological and biochemical properties of soil associated with C, N and P under different land uses in a farm property with diversified activity in northern Parana, Brazil. Seven areas under different land uses were assessed: fragment of native Atlantic Forest; growing of peach-palm (Bactrys gasipaes); sugarcane ratoon (Saccharum officinarum) recently harvested, under renewal; growing of coffee (Coffea arabica) intercropped with tree species; recent reforestation (1 year) with native tree species, previously under annual crops; annual crops under no-tillage, rye (Cecale cereale); secondary forest, regenerated after abandonment (for 20 years) of an avocado (Persea americana) orchard. The soil under coffee, recent reforestation and secondary forest showed higher concentrations of organic carbon, but microbial biomass and enzyme activities were higher in soils under native forest and secondary forest, which also showed the lowest metabolic coefficient, followed by the peach-palm area. The lowest content of water-dispersible clay was found in the soil under native forest, differing from soils under sugarcane and secondary forest. Soil cover and soil use affected total organic C contents and soil enzyme and microbial activities, such that more intensive agricultural uses had deeper impacts on the indicators assessed. Calculation of the mean soil quality index showed that the secondary forest was closest to the fragment of native forest, followed by the peach-palm area, coffee-growing area, annual crop area, the area of recent reforestation and the sugarcane ratoon area

COMPOSIÇÃO FLORÍSTICA E FITOSSOCIOLOGIA DO COMPONENTE ARBÓREO DAS FLORESTAS CILIARES DA BACIA DO RIO TIBAGI. 1. FAZENDA DORALICE - IBIPORÃ, PR

O presente trabalho trata do estudo florístico e fitossociológico de uma área da Fazenda Doralice, muni­cípio de lbiporã, PR. (23°16'8 e 51°01'W e 480 m de altitude). O clima apresentado é do tipo Cfa e o solo do tipo TRe3 - terra roxa estruturada eutrófica. O levanta­ mento foi realizado em área de 1 ha (10.000 m2), dividida em 100 parcelas de 10 x 10 m cada, demarcadas a partir da margem do rio. O inventário florístico registrou 1396 indivíduos reunidos em 39 famílias, 73 gêneros e 105 espécies. O índice de diversidade encontrado (SHANNON-WEAVER)foideH'=3,6.Sorocea bonpiandíí foi a espécie que atingiu o maior valor de importância (IVI), alcançando o maior valor de densidade (130 indi­ víduos/ha) e freqüência (comparecimento em 57 parce­ las), apesar de baixa dominância (2,24%). Gal/esia integrifolla alcançou o mais alto valor de dominância (10,58%). A família mais importante da comunidade é Me/iaceae, a qual alcançou os primeiros lugares em IVI, IVC, DR e FR e segundo lugar em DoR. Myrtaceae apresentou o maior número de espécies (14)