4 resultados para Field Work
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
This study aims to identify the flora and vegetation of rocky outcrops of low altitude and confined in the municipalities of Sobral, Groaíras and Santa Quitéria (Ceará state, Brazil), to propose a phytosociological classification for the xerophilous communities. We selected five stations in areas with high proportion of bare rock (> 80%), and the field work were conducted in March 2014 and 2015 respectively (3º 56’ S and 40º 23’ W, 4º 01’ S and 40º 05’ W, 4º 07’’ S and 40º 08’ W, 4º 09’ S and 40º 09’ W and 4º 03’ S and 40º 00’ W). Floristic relevés were made following the Braun-Blanquet classic sigmatist method. The minimum areas of the floristic relevés vary between 8 e 16 m². All the plant species growing in cracks, crevices and vegetation "spots" that can be found in these habitats were identified. The classification of the relevés was made through the Twinspan. The floristic list is composed of 89 species, distributed in 61 genera and 29 families. Fabaceae was the most representative in species richness, 20 species, followed by Poaceae (10 spp.), Euphorbiaceae (7 spp.) and Convolvulaceae (6 spp.). 22 Brazilian endemisms have been identified. Based in the phytosociological analysis and in the classification results we identified five groups and two communities can be clearly distinguished: community of Pilosocereus gounellei FA.C.Weber) Byles & Rowley and Encholirium spectabile Mart. ex Schult. & Schult.f. and the community of Crateva tapia L. and Combretum leprosum Mart..
Resumo:
The “dicótilo-palmácea” mixed forest is found in the fluvial plains (floodplains) of watercourses on the Ceará semiarid region (Brazil), distinguishing from the surrounding vegetation (caatinga) by the prevalence of larger tree species. In the river’s margins, presenting high variability in the extension of the riverbanks, arise floodplains in pedologic complexes mainly composed by neossols and argissols, resulting from the deposition of sediments. In these areas of high fertility soils and subjected to flooding during part of the year, it develops a particular type of riparian vegetation dominated by carnauba palm tree (Copernicia prunifera (Mill.) H.E. Moore) forming a particular type of riparian forest, designated by carnaubal palm forest. We aimed to carry out floristic and phytosociological surveys of carnauba palm forests located in the northern region of Ceará. The classical sigmatist method of Braun-Blanquet was applied and classification analysis (Twinspan) was perfomed. The field work occurred in March 2014 and 2016 in eight areas: Fazenda Pedra Branca (03º 37’ 10’’ S e 40º 18’ 30’’ W, 104 m asl), Vale do Rio Bom Jesus (04º 04’ 42’’ S e 39º 57’ 08’’ W, 200 m asl), Lagoa do Peixe (03º 56’ 28’’ S e 40º 23’ 23’’ W, 97 m asl), Fazenda Peixes (04º 06’ 03’’ S e 40º 32’ 43’’ W, 114 m asl), Fazenda Natividade (04º 02’ 50’’ S e 40º 29’ 03’’ W, 109 m asl), Fazenda Morro Alto (02º 53’ 42’’ S e 39º 54’ 51’’ W, 16 m asl), Fazenda Araticum (03º 04’ 58’’ S e 40º 09’ 36’’ W, 19 m asl) and Fazenda Experimental da UVA (03º 37' 04'' S 40º 18' 18'' W, 200 m asl).The floristic list consists of 170 species, distributed between 127 genera and 50 families. Twenty-seven Brazilian endemic species were identified, from which 8 are exclusive of the Caatinga biome. The Fabaceae was the most representative family, with the highest number of species (28), followed by Poaceae (17), Malvaceaea (14), Euphorbiaceae (12), Asteraceaea (9), Convolvulaceae and Rubiaceae (9). The dominant life forms were therophytes (34%), phanerophytes (30%) and chamaephytes (18%). Two communities were identified as a result of the classification analysis using the Twinspan.
Resumo:
The Caatinga, covering about 800.000 km2, is the predominant vegetation type of the semi-arid region of Brazil. The Caatinga biome comprises several phytophysiognomies and floristic compositions, with many endemic species, especially in Fabaceae, Cactaceae, Euphorbiaceae, Bignoniaceae e Combretaceae. Despite considerable advances, the Brazilian semi-arid needs more studies and inventories of biodiversity, especially the Ceará state. On the basis of these considerations, the present study aims to identify the flora and vegetation, in order to characterize the phytophysiognomy in an area of the Caatinga, in locality of Taperuaba, municipality of Sobral, Ceará, Brazil. Field work was conducted in March 2015 and 2016 respectively, in three transects. The life-forms were established in accordance of Raunkiaer´s system. The floristic list is composed of 87 species, distributed in 66 genera and 36 families. The flora comprises 22 Brazilian endemic species. The most representative family was Fabaceae with 15 species, followed by Malvaceae (7) Convolvulaceae (6), Euphorbiaceae (5) and Poaceae (5). The biological spectrum had a high proportion of therophytes (29,9%), chamaephytes (29,9%) and phanerophytes (26,4%). In the area were identified two phytophysiognomies: outcrops communities highlighting succulent phanerophytes (Pilosocereus chrysostele (Vaupel) Byles & G.D. Rowley subsp. cearensis P.J. Braun & Esteves and P. gounellei (F.A.C. Weber) Byles & Rowley), chamaephytes (Encholirium spectabile Mart. ex Schult. & Schult. f. and Lepidaploa chalybaea (Mart. ex DC.) H. Rob.) and therophytes (Mitracarpus baturitensis Sucre), mixed with communities including small trees and shrubs on deeper soil, composed of Cereus jamacaru DC., a succulent phanerophyte, and many woody phanerophytes, such as Cordia oncocalyx Allemão, Crateva trapia L., Mimosa caesalpiniifolia Benth., M. tenuiflora (Willd.) Poir., Poincianella bracteosa (Tul.) L.P. Queiroz and P. pyramidalis (Tul.) L.P. Queiroz.
Resumo:
Current pear pruning making use of pneumatic shears still is a very labour intensive operation. The Proder project “Avaliação da poda mecânica em pomares de pera” was designed to contribute to solutions that would reduce the present dependence in labour and therefore to promote a reduction in pruning costs. This paper shows the results of a trial made to evaluate the influence of mechanical topping in manual pruning complement field work and pear yield. Topping was performed using a Reynolds 6DT 3.0m cutting bar with six hydraulic-driven circular disc-saws mounted in the three point tractor linkage system. The field trial was performed in a commercial orchard with 20 years, planted in an array of 4m x 2m with tree lines oriented in North-South direction. Trees were trained as the central leader system. In this trial, in a randomised complete block design with four replications, two treatments are being compared leading to 8 plots with one line of 14 trees per plot. The treatments tests were: T1 - manual pruning performed by workers using pneumatic shears, in each year; T2 - Topping the canopy parallel to the ground, using a discs-saw pruning machine mounted in a front loader of an agricultural tractor, followed by manual pruning complement performed by workers with pneumatic shears. Tree height and width was measured, before and after pruning. Work was timed and pear yields evaluated. Mechanical topping seems to be effective in the control of tree height, which can contribute to increase 14% of work rates on manual pruning complement. No significant differences in pear yield were found between treatments.