The flora and communities Carnaubal Palm Forest in the northern region of Ceará - Brazil

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.

Progress in the use of scanning electron microscopy (SEM) applied to the taxonomy of the genus Bursaphelenchus (Nematoda: Parasitaphelenchidae)

The scanning electron microscope (SEM) has been a major tool in detailed morphological observations of plant parasitic nematodes during the last 30 years, efficiently complementing light microscopical (LM) studies. Nematodes are extremely difficult to observe and characterize due to their small size (aprox. 1 mm long) and paucity of morphological characters, so detailed surface observations of several organs and nematode regions are of the highest value. Among plant parasitic nematodes, one of the most devastating species is the “pinewood nematode” (PWN), Bursaphelenchus xylophilus, which has been a major problem for forest species, and in particular pines, in Asia (Japan, China, Korea) and has been recently detected in the European Union (Portugal). B. xylophilus belongs to a closely related, morphologically similar group of species, within the genus Bursaphelenchus, and designated by the “xylophilus group”. SEM has become a crucial tool in observing several genital characters of males and females, such as male genital papillae, male copulatory spicules, female vulval flap and female genital papillae.s In this presentation, we will show how SEM has been utilized to observe and characterize the shape of the vulval flap, the presence/ absence of papillae near the flap, and confirm the presence and the arrangement of the male genital papillae. LM is also used in this work to show its value as a complementary tool to SEM, in both genital characteristics and other, general, characters of the genus Bursaphelenchus, such as the male bursa and cephalic region.