Ecological theories of facilitation and nucleation are proposed as a basis for environmental restoration in tropical ecosystems. The main goal of this paper is to present restoration techniques based on the concept of nucleation, in which small nuclei of vegetation are established within a degraded land. The nucleation techniques (artificial shelters for animals, planting of herbaceous shrub life forms, soil and seed bank translocation, seed rain translocation, soil and seed rain translocation's seedling set, artificial perches, planting of native trees in groups, and ecological stepping-stones with functional groups) promote the landscape connectivity on two flows: inward: receiver connectivity and outward: donor connectivity. The nuclei development represents an alternative for restoration by prioritizing the natural processes of succession. This methodology appears to take long to generate vegetation corresponding to tropical climates, but is fundamental in the formation of communities capable of acting, in the future, as a new functional nuclei within the current fragmented landscape. This strategy also encourages greater integration between the theories and projects of ecological restoration for the development of human resources and to benefit the restoration practitioner.

Pinus is the most invasive woody taxon, exceeded only by herbaceous plants. This study reports the reproductive biology and early establishment of Pinus elliottii Engelm. var. elliottii, describing its invasive properties in a protected natural area of the Brazilian coastal sandy plains. We evaluated the seed germination and rain, longevity of seed viability and the initial dynamics of the seedlings of Pinus elliottii var elliottii through field and laboratory experiments. We recorded a continuous seed rain of about 204.0 viable seeds m- 2 per year, with a 90 % germination rate. The seeds exhibited a low longevity of viability in the soil and a dense, permanent seedling bank that may explain the high levels of pine invasion. The environmental impact caused by the pine's biological invasion suggests the recommendation for its immediate eradication, together with a restoration plan to restitute the native biodiversity gradually.

Ecological restoration encourages management for the complexity and heterogeneity of habitats, which are crucial for avian fauna structure. Two-year-old bird assemblages were evaluated based on diversity parameters of three different ecological restoration technologies applied in southern Brazil: passive restoration (PR), nucleation (NC) and high diversity plantation (HD). Richness, abundance and diversity were compared using ANOVA factorial design (three treatments × four seasons, with six samplings per season). The highest richness was observed for NC (49 ± 2.45 SD species) and the lowest richness occurred in the HD treatment (37 ± 3.14 SD species), with a similar statistical pattern for abundance and diversity (NC>PR>HD). NC responded favorably to the hypotheses of dynamic equilibrium, heterogeneity and habitat complexity, which are the probable mechanisms that influence primarily assemblage richness. Due to the presence of exclusive species for each treatment, we recommend the application of a mix of the different techniques tested to maximize the number of habitats and their interactions with birdlife.

Devido à crescente degradação ambiental, entender o funcionamento das técnicas de reflorestamento e outras técnicas de restauração tornou-se substancial para embasar a recomposição destes ecossistemas degradados. O objetivo deste trabalho foi monitorar a vegetação de uma área em restauração através de três diferentes técnicas. A área possui 7,2 ha em floresta subtropical em Dois Vizinhos, estado do Paraná, Brasil e encontra-se a aproximadamente 20 metros de um fragmento de floresta secundária. O experimento foi delineado através de 12 parcelas com três tratamentos (T1-3), distribuídas em quatro blocos casualizados. T1: regeneração natural através da restauração passiva. T2: conjunto de técnicas de nucleação. T3: plantio de mudas através de linhas de recobrimento e diversidade (3 x 2 m). Para fins de amostragem, cada parcela foi dividida em 24 subparcelas. Com a finalidade de avaliar a presença de plantas, após dois anos e oito meses da implantação dos tratamentos foi realizado um levantamento em três subparcelas aleatórias para cada parcela, em que foram identificados e quantificados todos os indivíduos maiores que 50 cm de altura. A riqueza de espécies nativas foi acima de 87% em todos os tratamentos, enquanto a presença de espécies herbáceas foi maior na restauração passiva e a de lenhosas no plantio. As síndromes de dispersão mais comuns foram anemocoria e zoocoria. Através da comparação entre os indivíduos plantados e regenerantes dos três tratamentos, a técnica de plantio apresentou a maior diversidade de Shannon (3,017) com 148 indivíduos e 53 espécies, entretanto, não houve diferença significativa. Essa maior diversidade está associada ao grande número de espécies plantadas, mas ainda não há a facilitação da regeneração de espécies em seu sub-bosque, nesta idade. Analisando-se apenas os indivíduos regenerantes, o tratamento que obteve maior diversidade de Shannon foi a nucleação (2,078) com um total de 908 indivíduos pertencentes a 40 espécies, contudo, esta não foi estatisticamente diferente da restauração passiva (Shannon = 1,965) que apresentou 2.018 indivíduos pertencentes a 40 espécies. Os tratamentos mais similares floristicamente, foram a restauração passiva e a nucleação. A nucleação facilitou a regeneração natural de espécies (17 espécies plantadas e 40 regenerantes) enquanto a restauração passiva evidenciou alta resiliência, desta forma, a utilização da restauração passiva pode ser considerada uma eficiente alternativa, uma vez que seus resultados não se diferiram estatisticamente da nucleação, e a principal vantagem desta técnica é o custo reduzido.

The understanding of silviculture of native species in a determined region is fundamental for the selection of more appropriate species for using in ecological restoration. Trema micrantha (Cannabaceae), a pioneer species which is widely distributed, shading and attractive to birds, is intensively planted in restoration projects of the southeastern Brazilian Atlantic Forest. In order to get information regarding to the performance of this species in subtropical forests (subject to the yearly frosts), we analyzed its early growth in a planting carried out with 70 native tree species in 3 x 2 m spacing in four plots of 40 x 54 m. Semianually, we collected data of 72 individuals of Trema micrantha. These data were statistically analyzed using the Statistical Software Assistat-beta submitted to Tukey test (p<0.05) and graphically described by R. Trema micrantha showed excellent performance at 3.5 years of age in root collar diameter (12.01 ± 5.24 cm), total height (5.95 ± 1.44 m), crown projection area (22.56 ± 11.26 m²) and crown volume (61.34 ± 37.46 m³), enduring severe frosts with a yearly survival rate of 78%. Based on the results obtained, and considering that this species has broad natural distribution, we recommend its extensive use also in forestry restoration projects in the subtropical regions of Brazil.