Setaria parviflora (knotroot foxtail).

S. parviflora is a variable, self-compatible, rhizomatous, C4 plant with a short lived seed bank, commonly regarded as an agricultural weed both in its native and introduced range (Rabinowitz and Rapp, 1981; Pensiero, 1999; Mollard et al., 2007; Mollard and Insausti, 2011; Randall, 2012). It often colonizes cultivated and disturbed soils or waste places including seasonally wet sites and salt marshes (Hubbard, 1954; Leithead et al., 1971; Pott and Pott, 2004; Edgar and Connor, 2010). It can contaminate wool (Ryves et al., 1996), seed crops, especially those of grasses such as dryland rice, lawn seed and Bahia grass (Paspalum notatum) (Silveira Filho and Aquino, 1983; Wehtje et al., 2008; Seed Regulatory and Testing Branch, 2011) and degrade and dominate sod and pastures (including alfalfa), lowering hay quality, a problem because it can cause lesions in livestock (Murphy et al., 1992; Arregui et al., 2001; Muller and Via, 2012). Land infested with it might be considered to have lower value because of poor pasture. It is regarded as a member of the alien flora of Chile (Ugarte et al., 2011).

Dieta de Cyclura nubila nubila Gray, 1831 (Squamata: Iguanidae) en dos cayos del archipiélago de los Jardines de la Reina, Cuba

Cyclura nubila nubila is an endemic subspecies of Cuba and it has been listed as Vulnerable in the IUCN Red List. The present investigation was developed in November 2013 and February 2014 in Caguamas and Palomo cays, respectively. Thirty-seven fecal pellets were collected through fixed transects on sandy coast vegetation and subsequently moistened with water and alcohol to separate and identify diet‘s components. Nine species of plants in Caguamas and four in Palomo were identified as part of iguana‘s diet. The most frecuent plant species were Conocarpus erectus, Setaria parviflora and Thalassia testudinum in Palomo and Cochorus hirsutus in Caguamas. In Palomo 45% of fecal pellets contained corporal parts of dragonflies and 5% parts of crabs. The consumption of animal matter is due to the low floristic diversity of Palomo cay. The iguana‘s diet in Caguamas included more plant components mainly fruits. This study contributes to increase knowledge of trophic ecology and management of the species in the archipelago of Jardines de la Reina.

Germination of native grasses with potential application in the recovery of degraded areas in Quadrilátero Ferrífero, Brazil

Native grasses are potential species to be used in land rehabilitation. However, due to the lack of better knowledge of their performance, preference is given to exotic plants, which may be invasive and negatively affect the local biodiversity. In order to better understand the propagation of native species of the Quadrilátero Ferrífero (Minas Gerais, Brazil) using their seeds, and in so doing, indicate possible candidates for land rehabilitation, this study investigated the germination patterns of the following grasses: Andropogon bicornis L.; Andropogon leucostachyus Kunth; Setaria parviflora (Poir.) Kerguélen; Cenchrus brownii Roem. & Schult; Echinolaena inflexa (Poir.) Chase, and Apochloa euprepes (Renvoize) Zuloaga & Morrone. The spikelets (depending on the species, removing or not the structures that surround the caryopsis) were treated as follows: T1-Control, T2-moistening with 0.2% potassium nitrate, T3-heating at 80 ºC for 2 minutes, T4-scarification with sulfuric acid (except genus Andropogon) and, for genera Andropogon and Setaria T5-storage at room temperature and T6- refrigerated storage. The treatment was repeated four times for 25 caryopses incubated at 25 ºC and constant light. Significant variation was observed when comparing germination rates from week to week, treatment to treatment and species to species. The most efficient treatment for genus Andropogon was T6, followed by T2 for A. bicornis and T3 for A. leucostachyus. T6 was also the most effective treatment for S. parviflora, followed by T5 and T2. C. brownii showed similar results when applying T1, T2 and T3 (mean 39%). E. inflexa and A. euprepes showed high levels of dormancy that were not overcome by the proposed treatments. A. bicornis, A. leucostachyus, S. parviflora and C. brownii showed higher germination potential, thus being possible candidates for the recovery of degraded areas. Future studies are indicated to find the most effective treatments for germination in field conditions.

Flooding induces secondary dormancy in Setaria parviflora seeds

The effect of flooding on the dormancy level of Setaria parviflora seeds from a non-flooded upland and a seasonally (winter–spring) flooded lowland in the Pampa grasslands of Argentina was investigated. Seeds from both communities were subjected to reciprocal burial treatments in the two habitats, and exhumed during and after the flooding season. Effect of immersion in water at 5°C was compared to incubation of seeds on the surface of water-saturated paper at the same temperature. After exhumation of the buried seeds or immersion treatments, germination was assayed at 25°C and at 20/30°C in the dark or in combination with light. Burial in the lowland, which was flooded in winter–spring, significantly reduced germination, while burial in the non-flooded upland did not reduce germination. Similarly, immersion in water at 5°C significantly reduced germination compared to non-immersed controls. During summer, seeds buried in the lowland showed increased capacity to germinate, particularly when exposed to fluctuating temperatures or light. Thus, flooding induced secondary dormancy in S. parviflora seeds, and it was broken during the non-flooding season. These responses of the seeds would prevent germination until there was no further risk of flooding. Remarkably, in S. parviflora seeds harvested from both habitats, we observed essentially the same germination requirements after flooding. However, some slight differences were detected between the seed populations exhumed from the lowland site, indicating that flooding had larger effects on the seeds from the upland community. This suggests some differentiation of these populations evident only after flooding in the field.