Natural regeneration may be a cost-effective method for recovering areas previously used for intensive agricultural purposes. Plant diversity in the succession periods has been well documented; ...however, less attention has been paid to the changes in soil attributes, which may work as an instrument for the validation of regeneration methods. The present study is part of a broader interdisciplinary research project assessing the effects of natural regeneration on biodiversity and the quality of the soil. We investigated the effects of natural regeneration on the physicochemical attributes of the soil, as well as on soil organic carbon (SOC), microbial biomass carbon (MBC) and enzyme attributes. We assessed three stages and five areas of each natural regeneration stage (early-ER, intermediate-IR and late-LR) in two layers: 0–5 and 5–10cm. The present study found a 20% SOC increase due to natural regeneration. In the first layer, SOC, urease, acid phosphatase and arylsulfatase absolute activities were significantly higher in the two older natural regeneration stages (IR and LR) than those found in the ER stage. We found a reduction in specific enzyme activities per SOC unit in the ER areas. Natural regeneration influenced SOC and MBC, the absolute enzyme activities, and the specific enzymes per SOC unit, mainly in the surface layer. The present study provided some of the first data concerning the beneficial effects of natural regeneration on the quality of soil as measured through enzyme activity, SOC and MBC in a tropical dry region in Northeastern Brazil.
•The natural regeneration improves the quality of a Cambisol in dry areas of Brazil.•15-year natural regeneration led to significant increase of 20% SOC.•The effect of natural regeneration was more evident in the 0–5cm soil depth.
Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We ...assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.
Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions ...from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km(2) of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.
Caracterização morfológica de minas foliares em espécies de Melastomataceae de Mata Atlântica, PE Brito-Ramos, Aretuza B(Universidade Federal de Pernambuco Departamento de Botânica); Almeida-Cortez, Jarcilene S(Universidade Federal de Pernambuco Departamento de Botânica); Alves, Marccus(Universidade Federal de Pernambuco Departamento de Botânica)
Acta botânica brasilica,
2010, Letnik:
24, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Este trabalho descreve a morfologia e a anatomia de folhas íntegras e minadas de cinco espécies de Melastomataceae, ocorrentes em um fragmento de Mata Atlântica, PE. As minas foram visualizadas em ...uma ou ambas as faces das folhas, possuindo padrão sinuoso ou retilíneo, distribuídas entre as nervuras ou por toda a lâmina, sendo estas características distintas para cada espécie. As folhas apresentam epiderme uniestratificada com estômatos presentes na face abaxial e tricomas dendríticos, multicelulares, estrelados e com mais de cinco ramos, em ambas ou apenas uma das faces. O mesofilo é dorsiventral e o sistema vascular em forma de arco. As larvas minadoras observadas em Miconia minutiflora (Bonpl.) DC., M. albicans (Sw.) Triana e Clidemia capitellata (Bonpl.) D. Don consomem o parênquima paliçádico e esponjoso, enquanto as de M. prasina (Sw.) DC. e M. ciliata (Rich.) DC. se alimentam do conteúdo e das paredes anticlinais das células epidérmicas, caracterizando-as como do tipo epidérmica. Entretanto, em M. minutiflora, M. albicans e C. capitellata a epiderme permaneceu intacta formando uma proteção para o minador, enquanto que em M. prasina e M. ciliata a proteção é realizada pelas paredes periclinais externas e cutícula da folha. Tecido de cicatrização foi observado ao longo das minas em M. prasina.
This study describes the morphology and anatomy of whole and mined leaves of five species of Melastomataceae native to an Atlantic Forest fragment in Pernambuco, Brazil. Mines can be found on one or both sides of the leaves, with a sinuous or rectilinear pattern, and distributed between the veins or throughout the entire leaf blade. These characteristics are distinct for each species. The leaves, in cross section, have a uniseriate epidermis, stomata on the abaxial surface, and unbranched hairs on both or at least one side. The mesophyll is bifacial and the vascular bundle is semi-circular. The leaf-miner larvae observed in Miconia minutiflora (Bonpl.) DC., M. albicans (Sw.) Triana and Clidemia capitellata (Bonpl.) D. Don consume the palisade and spongy parenchyma, while those found in M. prasina (Sw.) DC. and M. ciliata (Rich.) DC. feed only on the anticlinal walls of epidermal cells. All of these larvae, therefore, are characterized as parenchymatic miners. In Miconia minutiflora, M. albicans and C. capitellata the epidermis remains intact and offers some protection to the miners, while in M. prasina and M. ciliata only the periclinal walls of epidermal cells and leaf cuticle remain to offer protection. Wound tissue was observed along mines in M. prasina.
Insetos que induzem galhas podem constituir excelente ferramenta para estudos ambientais por serem sésseis, de fácil localização, abundantes e hospedeiro-específicos. Como bioindicadores respondem às ...perturbações ambientais mostrando perda de diversidade e alterações nas abundâncias populacionais tanto das espécies galhadoras como dos parasitoides. A importância ecológica das galhas despertou o interesse em descrever a morfologia e o padrão de distribuição espacial de galhas em três espécies de Croton (Croton adamantinus, C. argyrophyllus, C. grewioides) de região semi-árida. Para isso, foram levadas ao laboratório ramos de 10 indivíduos de cada espécie pra serem realizadas análise. Foram observadas, nas três espécies, galhas tanto foliares quanto caulinares com exceção de C. grewioides que só apresentou galhas foliares. A galha foliar do C. adamantinus apresentou coloração verde, pilosa, globóide, a galha caulinar mostrou-se de coloração marrom, glabra e ovóide. As galhas do C. argyrophyllus, tanto foliar quanto caulinar, apresentaram coloração amarelada, pilosa e globóide. Galhas em C. grewioides mostraram-se amareladas, pilosas, cilíndricas. As galhas de C. argyrophyllus estiveram presentes preferencialmente na face abaxial, região basal e borda da folha. Já as galhas em C. grewioides ocorreram em pequenas quantidades na face abaxial. Palavras-chave: Caatinga, Euphorbiaceae, Herbivoria. Occurrence of Galls on Species of Croton Catimbau Valley Nacional Park (PE) ABSTRACT Insects that induce galls can be an excellent tool for environmental studies because they are sessile, easy location, abundant and host-specific. As bioindicators respond to environmental perturbations showing loss of diversity and changes in population abundance of both species of parasitoids as galling. The ecological importance of galls sparked interest in describing morphology and pattern of spatial distribution of galls on three species of Croton (Croton adamantinus, C. argyrophyllus, C. grewioides) of semi-arid region. For this, they were taken to the laboratory branches 10 individuals of each species to be carried out analysis. Were observed in all three species, both leaf and stem galls with exception of C. grewioides only had leaf galls. The leaf gall of C. adamantinus presented color green, hairy, globose, stem gall proved to be brown, ovoid and glabrous. The galls of C. argyrophyllus both leaf and stem showed yellowish, globose and hairy. Galls in C. grewioides proved to be yellowish, hairy, cylindrical. The galls of C. argyrophyllus were present preferentially on abaxial, basal and edge of sheet. Since the galls in C. grewioides occurred in small quantities on abaxial surface.Keywords: Caatinga, Euphorbiaceae, Herbivonia.
Solanum stramonifolium Dunal. (Solanaceae) is a pioneer species very common in the Atlantic forest of northeast Brazil. The plants bear extrafloral nectaries (EFNs) that are frequently visited by ...ants. Ant exclusion experiments show reduced seed set in plants without ants. This paper describes the morphology and anatomy of the nectary of S. stramonifolium. This species bears structural EFNs, vascularized by both phloem and xylem. The nectary is located around the lower, external surface of the calyx, as a ring of five protuberances. Secretory cells are present only below these protuberances and arranged in several strata. The nectar is secreted by stomata situated on projections above the surface of these protuberances. Nectar secretion begins at the floral bud stage and continues through fruit development. We suggest that production of nectar during the entire reproductive period of S. stramonifolium functions as a mechanism of flower and seed protection.Key words: Solanaceae, Solanum stramonifolium, extrafloral nectaries, ants, plant-ant interactions.
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