Sergius Gandolfi

Colonization of gaps produced by death of bamboo clumps in a semideciduous mesophytic forest in south-eastern Brazil

The study was carried out in 16 gaps produced by bamboo clump death (Merostachys riedeliana Rupr. ex Doell) in a semideciduous mesophytic forest in the Santa Genebra County Reserve (22°49′45″ S and 47°06′33″ W), Campinas, SP, south-eastern Brazil. All shrub and tree individuals in the gap with height ≥ 0.50 m were sampled. The floristic similarity among the colonizing vegetation in these gaps and in gaps produced by treefall was assessed by the Jaccard similarity index and cluster analysis. The colonization process of these gaps was found to be similar to that in gaps formed by treefall, but this colonization only began after the bamboo clump death. The gap area varied from 35 m2 to 454 m2, but small gaps predominated. In the set of gaps, 3677 individuals were sampled belonging to 40 families, 83 genera and 114 species. The families with the greatest species richness in the gaps were Myrtaceae (10), Euphorbiaceae (9) and Solanaceae and Rubiaceae (8 each). The species with the greatest number of individuals in the gaps were the pioneers Celis tala Gillies ex Planchon and Croton priscus Muell. Arg. and the shade-tolerant shrubs Actinostemon klotschii (Muell. Arg.) Pax, Polygala klotzschii Chod., Psychotria hastisepala Muell. Arg. and Galipea multiflora Engl. Late secondary species predominated because of the greater number of small gaps. The gaps formed by bamboo clump death contributed to the successional and structural organization of the forest, creating suitable environments for colonization by shrub and tree species of the different successional groups.

Instrumentos legais podem contribuir para a restauração de florestas tropicais biodiversas

The failure of most efforts undertaken to restore natural high-diversity tropical forests, like the Atlantic Forest, has resulted in a very intense round of discussions on the science and best-practice of ecological restoration in the state of Sao Paulo, southeastern Brazil. This culminated in the participatory elaboration of a state resolution concerning technical and orientation aspects for restoration activities, which has been reviewed and updated periodically in workshops that bring together more than 200 professionals. The aim of this resolution was to maximize the establishment of biologically viable forests, with plant richness consistent with the reference ecosystem, to ensure the persistence of restored forests and protect native biodiversity. The contributions of this resolution for the improvement and stimulation of restoration actions are evident today. Between 2003 and 2008, when the resolution was heavily discussed, seedling production of native shrubs and trees in the state increased from 13,000,000 (55 nurseries) to 33,000,000 (114 nurseries) per year, and average number of plant species produced in nurseries also increased from 30 to over 80, reflecting the increase of restoration actions. In our view, the existing legal instrument has served well as a mechanism to accompany environmental public policy aimed at protection of the collective interests of society. In particular, it guides and orients the bulk of investments in ecological restoration and enhances the prospects for maximizing the societal benefits that can and should be obtained from restoration activities, including the persistence of biodiversity in human-modified tropical landscapes.

Permeability - impermeability: canopy trees as biodiversity filters

Each tropical and subtropical forest canopy species may create specific microsite conditions below its crown, which works as a filter for those species that attempt to regenerate below it. In function of the permeability or impermeability level, each canopy species could partially determine a plant community structure and composition beneath its crown projection. Therefore, present and future forest plant community biodiversity could be partially determined by the present structure of the canopy tree species community (filter effect). Some theoretical and practical aftermaths are suggested.

Repeated disturbances and canopy disturbance regime in a tropical semi-deciduous forest

The canopy disturbance regime and the influence of gap methods on the interpretation of forest structure anddynamicswereevaluatedinatropicalsemi-deciduousforestinsouth-easternBrazil.Weencounteredagapdensity of 11.2 gaps ha −1 and an average size which varied from 121 to 333 m 2 depending on the gap delimitation method considered (minimum gap size was 10 m 2 ). Although average size was slightly higher, the median value obtained (78 m 2 ) was comparable to other tropical forest sites and the gap size-class distribution found supported the pattern described for such forest sites. Among 297 gap makers, snapping and uprooting were the most common modes of disturbance.Thenumberandbasalareaofgapmakersweregoodpredictorsofgapsize.Almost25%ofallgapssuffered fromrepeateddisturbanceeventsthatbroughtaboutlargergapsizes.Suchprocesses,alongwithdelimitationmethods, strongly influenced the estimation of turnover rate and therefore the interpretation of forest dynamics. These results demonstrated the importance of further studies on repeated disturbances, which is often neglected in forest studies.

Allelopathic potential of bark and leaves of Esenbeckia leiocarpa Engl. (Rutaceae)

Allelopathic potential of bark and leaves of Esenbeckia leiocarpa Engl. (Rutaceae)). We investigated the inhibitory potential of aqueous extracts of bark and leaves of Esenbeckia leiocarpa Engl. on lettuce germination and early seedling growth. We compared the effects of four concentrations (100, 75, 50 and 25%) of each extract to water and polyethylene glycol (PEG 6000) solution controls for four replicates of 50 seeds for germination and four replicates of ten seedlings for seedling growth. The inhibitory effects of E. leiocarpa extracts on the percentage of germination and on the germination speed seemed to be more than simply an osmotic effect, except for the percentage of seeds germinated in bark extracts. When compared to water control, both bark and leaf extracts delayed germination, and leaf extracts also affected the percentage of germinated seeds. Leaf extracts of all concentrations strongly inhibited the development of seedlings and caused them some degree of abnormality; bark extracts also caused abnormalities and reduced seedling growth. Root development was more sensitive to the extracts than hypocotyl growth. The negative effects of leaf extracts on germination and seedling growth were more pronounced than those of bark extracts, and the overall effects of both extracts were positively correlated with extract concentrations.

Enriquecimento de florestas em processo de restauração: aspectos de epífitas e forófitos que podem ser considerados 1

Enrichment of forests in process of restoration: aspects of epiphytes and phorophytes that may be considered). Monitoring of forests in process of restoration has shown that they have not been achieving high diversity of life forms. Epiphytes, plants that live on host trees (phorophytes), are essential in an ecosystem. Thus, it is important to promote enrichment of forests using them. The aim of this work is to provide information for procedures of transplantation of epiphytes taken from forests that had to be cut off to areas that have been restored. In order to perform that, we analyzed survival and development of individuals of Aechmea bromeliifolia (Rudge) Baker (Bromeliaceae) a year after been transferred to six distinct host tree species, in a 23-year old Semideciduous Seasonal Forest. These variables did not significantly respond to any particular phorophyte species, bark roughness, or canopy cover. They showed significant differences according to the initial weight of the epiphytes. The middle-sized individuals (105.5 a 239.4 g) were the most successful in transplantations.

A importância das áreas ripárias para a sustentabilidade hidrológica do uso da terra em microbacias hidrográficas

Zonas riparias sao areas de saturacao hidrica, permanente ou temporaria, cuja principal funcao e a protecao dos recursos hidricos de uma microbacia. Essa pesquisa comparou a adequacao do uso do solo de dois cenarios de planejamento agricola de uma microbacia: o cenario convencional, representando o metodo usualmente empregado, que apenas considera as classes de capacidade de uso da terra, e o cenario hidrologico, que inclui a delimitacao e avaliacao das zonas riparias. Um estudo de caso foi realizado na Microbacia do Ribeirao Sao Joao (3.656 ha), no municipio de Mineiros do Tiete (Sao Paulo, Brasil). Mapas de Classe de Capacidade de Uso da Terra e de Adequacao do Uso do Solo foram elaborados, utilizando o Sistema de Informacao Geografica (SIG), para a construcao dos cenarios convencional e do proposto. Excluindo a Area de Preservacao Permanente (APP), o cenario convencional indicou que 59,0% da area destinada a agricultura esta adequadamente utilizada, 28,2% esta subutilizada e 2,6% esta sobreutilizada. O cenario proposto ou hidrologico, com inclusao da identificacao da zona riparia (24,9% da microbacia) mostrou que muitas areas que, no cenario convencional, possuem pouca restricao para o cultivo intensivo, como as classes II e III, sao zonas riparias, de sensibilidade hidrologica. Existem dentro dos limites da zona riparia 38,9% de classe de capacidade de uso III e 49,5% de classe IV. O planejador, desconsiderando a zona riparia, pode colocar em risco areas vitais que, se degradadas, representam danos para a saude e resiliencia da microbacia.

Enriquecimento de floresta em restauração por meio de semeadura direta de lianas 1

Diversity enhancement of a forest under restoration through direct seeding of lianas). The aim of this study was to analyze the feasibility of direct seeding of liana species in the understory of a restoring forest. Seeds of the species Phanera sp., Macfadyena unguis-cati (L.) A.H. Gentry, and Peltastes peltatus (Vell.) Woodson were submitted to germination tests considering the presence and absence of light and temperature cycle variation. These species were also planted under a canopy of four tree species in a 21-year-old restored forest in Iracemapolis, Sao Paulo State, Brazil. Macfadyena unguis-cati was the only species presenting a positive photoblastic characteristic, while the two other tested species were not affected by light or temperature cycle. In the understory, Peltastes peltatus did not emerge. In the two other species, seed germination was not influenced by the selected tree species. These results suggest that despite the low rate of emergence, it is possible to enhance the diversity of forest by restoring it through direct seeding of some liana species.

Natural regeneration in abandoned fields following intensive agricultural land use in an Atlantic Forest Island, Brazil

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

Fenologia da frutificação de espécies vegetais nativas e a restauração florestal no arquipélago de Fernando de Noronha, PE, Brasil

Fructification phenology of native plant species and the forest restoration in Fernando de Noronha archipelago, Pernambuco State, Brazil). The annual pattern of fructification phenology of 23 native species of trees and bushes of Fernando de Noronha, Pernambuco State, Brazil was characterized with the aim of guiding the seed collection towards the implementation of a local restoration program. It was found that most species (74%) presented higher absolute frequencies of fructification during the rainy season (January to July) as opposed to 26% during the dry season, and the fructification lasted, on average, one month and a half. The Spearman correlation coefficient indicated a positive correlation between the studied phenophases and the precipitation. This kind of study is strategic for planning the seed collection and seedling production for restoration programs, especially in places where the process of Ecological Restoration is just beginning and still lacks information, such as Fernando de Noronha.