Identificação de áreas preferenciais para uso de espécies florestais potenciais em sistemas agroflorestais no Arco Verde Paraense

O desmatamento é um processo evidente na Amazônia oriundo da ação antrópica predatória dos recursos naturais. A extração madeireira e a agropecuária são as principais atividades que tem promovido a destruição da floresta no Arco do desmatamento. Entretanto, o reflorestamento tem sido o foco de políticas públicas que o Governo tem desenvolvido por meio do Programa Arco Verde. No Pará este projeto está sendo aplicado em 16 municípios que integram as áreas críticas de desmatamento devido às pressões antrópicas exercidas. Nesse contexto, os sistemas agroflorestais tem sido uma das alternativas para reflorestamento dessas áreas. Neste trabalho objetivou-se a identificação de áreas preferenciais para plantio de 15 espécies florestais potenciais para uso em sistema agroflorestais. A partir do mapeamento da ocorrência das espécies florestais selecionadas, e do cruzamento de dados geográficos de tipologia climática e deficiência hídrica, identificou-se 24 zonas bioclimáticas no Arco Verde paraense. Os resultados para o plantio das espécies florestais em áreas preferenciais foram: J. copaia, T. serratifolia e B. excelsa são potenciais para serem plantadas em 100% do Arco Verde Paraense; C. pentandra, H. courbaril, S. morototoni e T. vulgaris são indicadas para serem plantadas em 98% da área alvo; C. odorata, C. goeldiana, D. odorata, S. macrophylla são indicadas para serem inseridas em 75% do Arco Verde paraense; C. guianensis, S. parahyba var. amazonicum, B. guianensis e V. maxima em 60% da área estudada. Em suma, é necessário se intensificar estudos em espécies florestais que são indicadas para as áreas preferenciais mais abrangentes.

Isolamento de microssatélites de espécies madeireiras no contexto da sustentabilidade genética no manejo florestal

Aborda isolamento de microssatélites de espécies madeireiras no contexto da sustentabilidade genética no manejo florestal com o objetivo de isolar e caracterizar uma bateria de marcadores microssatélites para espécies arbóreas da Floresta Amazônica: Jacaranda copaia, Bagassa guianensis e Dipteryx odorata. Estes estudos vem sendo realizados como parte do projeto Dendrogene, e as análises genéticas populacionais posteriores fornecerão subsídios para conservação e manejo sustentável destas espécies.

Subdoses de glyphosate no desenvolvimento de espécies arbóreas nativas

Recovery of degraded areas aims to provide the degraded environment favorable conditions for restructuring in an environment that is unable to regenerate itself and planting of tree seedlings is one of the effective ways to extend this process. However, native tree species have slow growth rate which increases the seedlings production time as well as decreases their competitiveness with weeds in areas of forests deployment. The aim of this study was to evaluate the effects of glyphosate reduced rates application on Psidium cattleyanum (yellow guava), Citharexylum myrianthum (pau-viola) and Cedrela odorata (cedro) seedlings development by analyzing its morphophysiological parameters. The experiment was carried out in greenhouse conditions and the experimental units consisted of one plant were conducted in 2.5L plastic pots and arranged in a completely randomized design with six replications. Treatments consisted of glyphosate application at 0, 7.5, 15, 30 and 60 g ha(-1) using Scout (R) commercial formulation. Treatments application on these species seedlings was realized 120 days after seeds germination. Visual evaluations of plants phytotoxicity were realized at 7, 14 and 21 days after treatments application and plants survival, stomatal conductance, height, stem diameter and dry mass of shoots were evaluated 90 days after treatments application. Different doses of glyphosate did not cause plants phytotoxicity. Already, 30 and 60 g ha(-1) of glyphosate provided greater increases in height, stem diameter and dry mass of shoots for Citharexylum myrianthum and Psidium cattleyanum, respectively.

Evaluation of longitudinal modulus of elasticity in wood species for structural application

1024x768 This research aimed to investigate possible differences in values of longitudinal modulus of elasticity for wood species usually employed for structural purposes, as Castanheira (Bertholletia excelsa), Cambará (Erisma uncinatum), Cumaru (Dipteryx odorata), Jatobá (Hymenaea stilbocarpa), Garapa (Apuleia leiocarpa) and Peroba Rosa (Aspidosperma polyneuron), obtained from compression and tension parallel to grain, and static bending tests. Recommendations of the Brazilian standard ABNT NBR 7190:1997, Annex B, were followed. Statistical analysis results for the cited properties, had equivalent averages for the six wood species analyzed. This confirms that any of the three tests can be used to obtain the longitudinal elastic modulus and which could avoid the necessity of evaluating stiffness values for wood by more than one kind of mechanical test. Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Aluminum toxicity to tropical montane forest tree seedlings in southern Ecuador: response of biomass and plant morphology to elevated Al concentrations

In acid tropical forest soils (pH < 5.5) increased mobility of aluminum might limit aboveground productivity. Therefore, we evaluated Al phytotoxicity of three native tree species of tropical montane forests in southern Ecuador. An hydroponic dose-response experiment was conducted. Seedlings of Cedrela odorata L., Heliocarpus americanus L., and Tabebuia chrysantha (Jacq.) G. Nicholson were treated with 0, 300, 600, 1200, and 2400 mu M Al and an organic layer leachate. Dose-response curves were generated for root and shoot morphologic properties to determine effective concentrations (EC). Shoot biomass and healthy leaf area decreased by 44 % to 83 % at 2400 mu M Al, root biomass did not respond (C. odorata), declined by 51 % (H. americanus), or was stimulated at low Al concentrations of 300 mu M (T. chrysantha). EC10 (i.e. reduction by 10 %) values of Al for total biomass were 315 mu M (C. odorata), 219 mu M (H. americanus), and 368 mu M (T. chrysantha). Helicarpus americanus, a fast growing pioneer tree species, was most sensitive to Al toxicity. Negative effects were strongest if plants grew in organic layer leachate, indicating limitation of plant growth by nutrient scarcity rather than Al toxicity. Al toxicity occurred at Al concentrations far above those in native organic layer leachate.

Aluminum toxicity in a tropical montane forest ecosystem in southern Ecuador

Aluminum phytotoxicity frequently occurs in acid soils (pH < 5.5) and was therefore discussed to affect ecosystem functioning of tropical montane forests. The susceptibility to Al toxicity depends on the sensitivity of the plant species and the Al speciation in soil solution, which can vary highly depending e.g., on pH, ionic strength, and dissolved organic matter. An acidification of the ecosystem and periodic base metal deposition from Saharan dust may control plant available Al concentrations in the soil solutions of tropical montane rainforests in south Ecuador. The overall objective of my study was to assess a potential Al phytotoxicity in the tropical montane forests in south Ecuador. For this purpose, I exposed three native Al non-accumulating tree species (Cedrela odorata L., Heliocarpus americanus L., and Tabebuia chrysantha (Jacq.) G. Nicholson) to increased Al concentrations (0 – 2400 μM Al) in a hydroponic experiment, I established dose-response curves to estimate the sensitivity of the tree species to increased Al concentrations, and I investigated the mechanisms behind the observed effects induced by elevated Al concentrations. Furthermore, the response of Al concentrations and the speciation in soil solution to Ca amendment in the study area were determined. In a final step, I assessed all major Al fluxes, drivers of Al concentrations in ecosystem solutions, and indicators of Al toxicity in the tropical montane rainforest in Ecuador in order to test for indications of Al toxicity. In the hydroponic experiment, a 10 % reduction in aboveground biomass production occurred at 126 to 376 μM Al (EC10 values), probably attributable to decreased Mg concentrations in leaves and reduced potosynthesis. At 300 μM Al, increased root biomass production of T. chrysantha was observed. Phosphorus concentrations in roots of C. odorata and T. chrysantha were significantly highest in the treatment with 300 μM Al and correlated significantly with root biomass, being a likely reason for stimulated root biomass production. The degree of organic complexation of Al in the organic layer leachate, which is central to plant nutrition because of the high root density, and soil solution from the study area was very high (mean > 99 %). The resulting low free Al concentrations are not likely to affect plant growth, although the concentrations of potentially toxic Al3+ increased with soil depth due to higher total Al and lower dissolved organic matter concentrations in soil solutions. The Ca additions caused an increase of Al in the organic layer leachate, probably because Al3+ was exchanged against the added Ca2+ ions while pH remained constant. The free ion molar ratios of Ca2+:Al3+ (mean ratio ca. 400) were far above the threshold (≤ 1) for Al toxicity, because of a much higher degree of organo-complexation of Al than Ca. High Al fluxes in litterfall (8.8 – 14.2 kg ha−1 yr−1) indicate a high Al circulation through the ecosystem. The Al concentrations in the organic layer leachate were driven by the acidification of the ecosystem and increased significantly between 1999 and 2008. However, the Ca:Al molar ratios in organic layer leachate and all aboveground ecosystem solutions were above the threshold for Al toxicity. Except for two Al accumulating and one non-accumulating tree species, the Ca:Al molar ratios in tree leaves from the study area were above the Al toxicity threshold of 12.5. I conclude that toxic effects in the hydroponic experiment occurred at Al concentrations far above those in native organic layer leachate, shoot biomass production was likely inhibited by reduced Mg uptake, impairing photosynthesis, and the stimulation of root growth at low Al concentrations can be possibly attributed to improved P uptake. Dissolved organic matter in soil solutions detoxifies Al in acidic tropical forest soils and a wide distribution of Al accumulating tree species and high Al fluxes in the ecosystem do not necessarily imply a general Al phytotoxicity.

Pollen record and calculated holocene vegetation and climate dynamics from Sihailongwan Maar Lake, NE China

High-resolution palynological analysis on annually laminated sediments of Sihailongwan Maar Lake (SHL) provides new insights into the Holocene vegetation and climate dynamics of NE China. The robust chronology of the presented record is based on varve counting and AMS radiocarbon dates from terrestrial plant macro-remains. In addition to the qualitative interpretation of the pollen data, we provide quantitative reconstructions of vegetation and climate based on the method of biomization and weighted averaging partial least squares regression (WA-PLS) technique, respectively. Power spectra were computed to investigate the frequency domain distribution of proxy signals and potential natural periodicities. Pollen assemblages, pollen-derived biome scores and climate variables as well as the cyclicity pattern indicate that NE China experienced significant changes in temperature and moisture conditions during the Holocene. Within the earliest phase of the Holocene, a large-scale reorganization of vegetation occurred, reflecting the reconstructed shift towards higher temperatures and precipitation values and the initial Holocene strengthening and northward expansion of the East Asian summer monsoon (EASM). Afterwards, summer temperatures remain at a high level, whereas the reconstructed precipitation shows an increasing trend until approximately 4000 cal. yr BP. Since 3500 cal. yr BP, temperature and precipitation values decline, indicating moderate cooling and weakening of the EASM. A distinct periodicity of 550-600 years and evidence of a Mid-Holocene transition from a temperature-triggered to a predominantly moisture-triggered climate regime are derived from the power spectra analysis. The results obtained from SHL are largely consistent with other palaeoenvironmental records from NE China, substantiating the regional nature of the reconstructed vegetation and climate patterns. However, the reconstructed climate changes contrast with the moisture evolution recorded in S China and the mid-latitude (semi-)arid regions of N China. Whereas a clear insolation-related trend of monsoon intensity over the Holocene is lacking from the SHL record, variations in the coupled atmosphere-Pacific Ocean system can largely explain the reconstructed changes in NE China.

Pollen profiles from three former lakes in the Lake Garda area

1. Late glacial and postglacial sediments from three former lakes in the Lake Garda area (Southern Alps) were investigated. 2. The pollen diagram from Bondone (1550 m) shows an older phase rich in NAP. A younger one corresponds with the Younger Dryas time according to two radiocarbon determinations. In the Preboreal no climatic deterioration could be found. 3. At first plants, which are nowadays typical for snow-ground, pioneer and dwarf shrub associations, immigrated into the surroundings of Bondone. In Alleröd times larch and pine appeared as the first trees. At the beginning of the Preboreal dense forest existed in that region. During the Alleröd timber line was at about 1500 m. 4. In the pollen diagrams from Saltarino (194 m) and Fiavè (654 m) an oldest period rich in NAP is followed by two stadial and two interstadial phases. Tree birches and larches immigrated during the oldest interstadial phase. 5. In the case of Saltarino and Fiavè only a preliminary dating could be made. A correlation seems to be possible with diagrams published by Zoller as well as with the diagram of Bondone. Discrepances in dating, which arise then, are discussed. According to the two possibilities of dating the youngest stadial is synchronous either with the so-called Piottino stadial or the Younger Dryas time. Consequently the oldest interstadial phase of Saltarino corresponds either with the Bölling or with a pre-Bölling interstadial. The last possibility seems to be more probable. 6. In the southern part of the Lake Garda area reforestation was preceded by a long shrub phase mainly with Juniperus. At about 650 m there was a period with Pinus mugo and only with a small amount of Juniperus before reforestation. A phase with Betula nana well known from areas north of the Alps could nowhere be found. 7. In the area under study larch appeared as the first tree. Lateron it has been the most important constituent of the forests near timber line. Birch, which plays an important role as a pioneer tree in Denmark - for instance at the transition of the pollen zones III/IV - as well as in Southern Germany during Bölling time, was of less importance at the southern border of the Alps. In that area the spreading of Pinus occurred very early causing dense forests. 8. During the last stadial phase (probably Younger Dryas time) dense forests with Pinus and Larix existed at 650 m. In the lower part of the Lake Garda area, however, both thermophilous trees as Quercus and herbs frequently occurred. This leads to the conclusion that during this time tree growth was limited by dryness in lower altitudes of the border of the Southern Alps. Pinus and Juniperus, however, do not show higher values in this period, a fact which cannot yet be explained. 9. A list of plants, which were found in the sediments, is compiled. Helodium lanatum, Dictamnus albus, Mercurialis cf. ovata, Buxus, Cerinthe cf. minor, Onosma, Anthericum and Asphodelus albus are findings, which are of special interest for the history of the flora of that region.

Principales maderas tropicales utilizadas en España: Características, tecnología y aplicaciones

Se describen las características de las principales maderas tropicales con uso en España. La descripción incluye el nombre científico, sinonimias, nombres vulgares, su distribución en el mundo y en España, la descripción del fuste y de las trozas, con sus defectos más característicos, la descripción de la madera, sus características físicas, mecánicas, resistentes y durables. También se incluye sus aspectos tecnológicos, en el sentido de indicar que aspectos deben considerarse a la hora de trabajar estas maderas. Por último se indican los usos más comunes de las distintas maderas, las ventajas e inconvenientes frente a otras maderas Las especies principales que se describen son las siguientes: Algarrobo blanco, Prosopis alba, Grisebach Andiroba, Carapa guianensis, Aubl. Balsamo, Myroxylon balsamun, Harms. Sandwith. Barba jolote, Pithecolobium arboreum (L), Urban. Bubinga, Guibourtia tessmanii Caoba, Swietenia macrophylla, King. Cedro, Cedrela odorata, L. Cenizaro, Pithecellobium saman, (Jacq.) Benth Chinchon, Guarea grandiflora, A. DC. Cocobolo, Dalbergia retusa, Hemsl Cristobal, Platysmicium polystachyum Elondo o tali, Erythrophleum ivorensis Espavé, Anacardium excelsum, Skeels Gonzalo Alves, Astronium graveolens, Jacquin. Guayabillo, Terminalia lucida, Hoff. Guapaque, Dialium guianense, (Aubl.) Sandwith. Guayacán, Guaiacum sanctum, L. Huesito Homalium racemosum, Jacq. Ipe, Tabebuia guayacan, Hemsl. Iroko, Milicia excelsa Sim Jatoba, Hymenaea courbaril L. Machiche, Lonchocarpus castilloi, Standley. Manil, Symphonia globulifera, L. Marupa, Simarouba glauca, DC. Melina, Gmelina arborea, Roxb. Mongoy, Guibourtia ehie J. Léonard Nance, Byrsonima crassifolia (L.), H.B.K. Nazareno, Peltogyne purpurea Nispero, Manilkara zapota, (L.) Van royen. Palo blanco, Cybitax donnell- smith , Seibert. Pino amarillo, Erblichia odorata Piojo, Tapirira guianensis, Aubl. Quaruba, Vochysia guatemalensis, Donnell Smith Quira, Platysmicium pinnatum. Redondo, Magnolia yoroconte, Dandy. Rosul, Dalbergia tucurensis, Donn-Smith. Sande, Brossimiun ssp San juan areno, Ilex ssp. Saqui-saqui, Bombacopsis quinatum, (Jacq.) Dugand Santa maría, Calophyllum brasílíense Camb. Sapelly, Entandrophragma cylindricum Sprague Tamboril, Enterolobium cyclocarpum, Gris Teca, Tectona grandis, L.F.. Ukola, Tieghemella africana Ururucana, Hieronyma alchorneoides, Allem