Distribution Strategies of Vascular Plants at the Reclaimed Lands at the Saemangum Sea Dike

The distribution of plant communities in the reclaimed land of the southwestern coasts of South Korea, along with the environmental or plant factors, was studied through canonical correspondence analysis (CCA) and the competitor (C), stress tolerator (S), and ruderal (R) (CSR) ecological strategies. The coastal reclaimed land plants were classified into three plant-factor groups in the CCA biplot diagram. Axis1 was correlated with LS, SLA, CH, and FS. Axis 2 was correlated with LDMC, FP, and LDW. The reclaimed landplants were classified into three soil-factor groups in the CCA biplot diagram. First, the group factor was correlated with SAND. Second, the group factor was distributed according to T-N and TOC. Third, the group factor was distributed according to Salinity content. To clarify the relative significance of competition, stress, and disturbance in the distribution process of plant communities, the CSR distribution model was adopted. Sixteen of the 19 species were allocated to the factors related to the ruderals strategies such as R/CR and CR including R/CSR, SR/CSR, and CR/CSR, and SC strategies. They displayed ruderal and competition adaptation strategies reflecting the ecological environment. Seven species showed R/CR (ruderal/competitor-ruderal) strategies; Aeschno meneindica, Chenopodium album var. centrorubrum, Lolium perenne, Lotus corniculatus var. japonicus, Phragmites communis, Portulaca oleracea, and Soncous brachyotus and 6 species showed CR (competitor-ruderal) strategies; Bidens frondosa, Echinochloa crus-galli, Echino chloaoryzicola, Erigeron canadensis, Fimbristy lislongispica and Setaria viridis. The three species with R-related strategies were Artemisia princeps, Lolium perenne, and Trifolium repens. The distribution patterns of the CCA diagrams and CSR triangles may provide a useful scientific basis for protecting and restoring reclaimed lands and their valuable ecosystem services, from the increasing disturbances.

Primera aproximación de carga animal óptima en cuyes al pastoreo durante la época lluviosa en la sierra peruana

Se realizó una primera aproximación de la carga animal óptima en cuyes al pastoreo durante la época lluviosa en la sierra del Perú, utilizando una pastura perenne asociada conformada por Lolium multiflorum, Lolium perenne, Dactylis glomerata, Trifolium pratense, Trifolium repens y Medicago sativa en función a la ganancia de peso vivo individual y por unidad de área, consumo de alimento, conversión alimenticia, rendimiento de pastura, costos de producción y ratio beneficio costo. Se emplearon 132 cuyes machos G de 15 días de edad en un diseño de bloques completos al azar con tres ciclos de engorde de 60 días como bloque y cuatro tratamientos correspondientes a cargas de 400 (T1), 500 (T2), 600 (T3) y 700 (T4) cuyes/ha/año. Se trabajó en áreas de 200 m2 de pastura donde pastorearon grupos de 8, 10, 12 y 14 cuyes en T1, T2, T3 y T4, respectivamente. Los resultados demostraron que no hubo efecto de la carga animal sobre la ganancia de peso individual, consumo de alimento, conversión alimenticia y rendimiento de pastura (p>0.05). Los efectos sobre la ganancia por unidad de área y ratio beneficio costo (p<0.05) fueron consecuencia directa y esperada del diferente número de animales entre cargas animales. El rango de carga animal fue insuficiente para determinar una carga óptima, de manera que tentativamente se sugiere utilizar la carga de 700 cuyes/ha/año, por ser la carga que favorece lograr más cuyes con parámetros productivos similares a cargas menores y mejores parámetros económicos.

The effect of amendments on Lolium perenne roots arbuscular mycorrhizal fungi colonization when cultivated in contaminated soil

Arbuscular Mycorrhizal Fungi that colonize the roots of plants growing on lands contaminated by heavy metals may influence the phytostabilization process reducing the translocation of metals to the aboveground parts of the plant. This study aimed to evaluate the effects of soil amendments (lime and lignite) on the concentration of the bioavailable form of heavy metals (CaCl2 extraction) in soil and on the colonization of Arbuscular Mycorrhizal Fungi in the roots of Lolium perenne when cultivated in contaminated soil. During the experiment, the bioavailability of Pb, Cd, and Zn in soil was significantly reduced after application of the amendments, causing an increase of L. perenne shoot dry biomass. It was observed that the higher dose of lime (0.5%) resulting in amplified values of relative mycorrhizal intensity. However, independently of the dose, the treatments increased the occurrence of arbuscules in L. perenne roots, with the highest value observed after the application of 0.25% lime with 5% lignite. The results for the first time present the effect of lime and lignite application on the L. perenne roots colonization by Arbuscular Mycorrhizal Fungi indicating the increase of occurrence of arbuscules. These findings suggest that in order to explain the different responses of Arbuscular Mycorrhizal Fungi to the applied treatment further investigations are needed to identify the spore morphology. The results of the experiment were implemented to stabilize heavy metals during remediation of a spoil heap in Ruda Śląska, Poland.