Contribution of Erythrina protein banks and rejected bananas for improving cattle production in the humid tropics

In view of the low pasture productivity in the Central American humid tropics where cattle rearing is a major land-use activity, it is important to examine the potential of alternate feed sources for ruminant feeding. Erythrina berteroana Uban, locally known as poro, and green banana (Musa AAA) fruits have been identified as two such potential sources. The effects of feeding poro as a grazing supplement and diet supplementation with green banana fruits on cattle productivity were evaluated in a long-term trial in Costa Rica. Daily liveweight (LW) gains were measured and samples of all feed material were analyzed for crude protein and in vitro dry matter (DM) digestibility. Pasture availability was high, averaging 0.17 t DM ha day^–1 over the grazing period. The main grass species were Paspalum fasciculatium Poiret, Axonopus compressus Swartz and to a lesser extent African star grass (Cynodon nlemfluensis Vanderyst). DM yields of poro declined significantly with time (> 50%) when it was managed with a two-month resting period but remained higher when subsequently managed with a three-month resting period. Average daily LW gain of animals was 21% to 26% higher with two hours daily browsing of poro than for animals only grazing pasture. Highest liveweight gain was achieved when diets were supplemented with banana and there was no additional benefit when poro was fed in addition to banana. This suggests that fodder banks of poro or supplements with green banana can improve cattle nutrition in the humid tropics.This revised version was published online in November 2005 with corrections to the Cover Date.     

The influence of stoniness and canopy properties on soil water content distribution: simulation of water movement in forest stony soil

Mountainous forest soils usually contain a large number of rock fragments (particle diameter >2?mm), which influence soil properties. Data characterizing hydraulic properties of these soils usually describe only the fine soil fraction (particle diameter <2?mm) properties. To quantitatively describe soil water movement in stony soils, it is necessary to evaluate effective hydrophysical characteristics, involving the influence of stones, that is, the effective hydraulic conductivity and retention capacity should be known. Properties of evaporating surface (plant canopy) also play important role in formation of soil water movement and retention. This work presents results of the study of rock fragments (stoniness) effect on soil water content profiles and soil water dynamics during the season. Stony and homogeneous soil behavior is compared. The effect of different canopies (spruce forest, low vegetation) and bare soil in both types of soils on soil water dynamics is also studied. Stones as a part of soil are decreasing its water capacity and hydraulic conductivity as well. This is expressing in the decrease of stony soil water content retention capacity. High interception capacity of trees, followed by the low undercanopy precipitation, leads to the decreased soil water content of the upper soil layer. Combination of stony soil and dense forest canopy led to the low undercanopy precipitation, to relatively low infiltration totals into soil, and to decreased outflow.     

Origin of the acetylated structures present in white birch (Betula pendula Roth) milled wood lignin

The occurrence and nature of acetate groups in the milled wood lignin (MWL) isolated from birch (Betula pendula Roth) has been addressed by spectroscopic (2D-NMR) and chemical degradative (derivatization followed by reductive cleavage, DFRC) methods. Considerable amounts of acetate groups were present in the MWL preparation. However, 2D-NMR analysis indicated that the lignin polymer is not extensively acetylated and that the major part of the acetate groups is attached to the xylan moieties present in the MWL preparation. Nevertheless, evidence of the presence of minor acetylation of the γ-carbon of the lignin side chain (<3% of both syringyl and guaiacyl lignin units) was provided by DFRC analysis.     

Do ecological and silvicultural factors influence acorn mass in Holm Oak (southwestern Spain)?

The effect of orientation, location, year, and pruning treatment on mean acorn mass in two open woodland experimental locations (Huelva, South-Western Spain) of Holm Oak (Quercus ilex L. subsp. ballota [Desf.] Samp.) was analyzed during 2001–2006. Data were analyzed by using a mixed linear model, where the covariates were tree size parameters (circumference at 80 cm height, crown size), topographic position (wet index and flow length), intraspecific competition, total acorn crops per tree (weight and number), and climatic parameters. Average estimated acorn mass was 3.17 g acorn^?1 in the Calañas location and 4.12 g acorn^?1 in the San Bartolomé location, with significant differences between locations, among individual trees and across years. Acorns from the south sides of trees were significantly heavier than those at other positions. The effect of pruning treatment and the interactions location × treatment and treatment × year were not significant. Our study provides no evidence that pruning affects acorn mass. None of the analyzed covariates related to tree size, topographic position and intraspecific competition explained the difference among trees, suggesting that heritable factors play an important role. Specific climatic parameters during September, the most important month for acorn growth, may explain the effects of year and location × year on acorn mass. In addition, there appeared to be a “trade-off” between acorn mass and number of acorns.     

Evidence that the negative relationship between seed mass and relative growth rate is not physiological but linked to species identity: a within-family analysis of Scots pine

Seed mass and relative growth rate (RGR) are important determinants of early seedling growth, and hence seedling establishment. Although a positive interspecific relationship between seed mass and seedling dry mass is well established, much less is known about the relationships among seed mass, seedling mass and RGR within species. We examined relationships among seed mass, seedling mass and RGR within and among maternal plant lines of Scots pine (Pinus sylvestris L.). To assess the effects of seed mass and maternal origin on RGR, individual seeds from two seed crops (years 2004 and 2005) of ten maternal plants growing under nursery conditions were weighed and then germinated. Seed mass was strongly determined by maternal plant, and seedling mass was largely determined by seed mass, with a positive correlation between these variables both across and within maternal plants. In contrast, RGR was weakly related to seed mass, with no consistent pattern in the sign of the relationship. It is well known that species differ in RGR and that RGR is related to seed mass across species. Lack of consistent evidence for this relationship within maternal lines, and for Scots pine overall, suggests that the relationship is not directly causal, but reflects consistent evolutionary covariation in these two physiologically independent traits.     

Calcium mineral nutrition increases the tolerance of Quercus ilex to Phytophthora root disease affecting oak rangeland ecosystems in Spain

Root rot caused by the soil-borne pathogen Phytophthora cinnamomi is leading to significant oak tree mortality in rangeland ecosystems in south western Spain. Susceptibility to P. cinnamomi infections of Q. ilex seedlings with a standard nutrition, deficient in K⁺, and deficient in Ca²⁺, was tested. Oaks deficient in K⁺ showed high values in Ca²⁺ content and were tolerant to the disease. Nutritional deficiency in Ca²⁺, however, did not lead to a higher K⁺ level in plants and induced poorer root development. In addition, K⁺ plant content does not appear to have any effect on pathogen tolerance. Based on these results, we conclude that satisfactory calcium nutrition may confer Holm oaks with a greater tolerance to root disease caused by P. cinnamomi. For this reason, limestone supplements are recommended as a measure against root rot caused by P. cinnamomi in rangelands in southern Spain, as a good option for control of oak root disease.     

Assessing mass trapping efficiency and population density of Cerambyx welensii Küster by mark-recapture in dehesa open woodlands

A severe oak decline is taking place across the Mediterranean region since the 1980s. Among the climatic and biological factors involved in this complex syndrome, the longhorn C. welensii is currently considered a major element. Furthermore, larval damage to young or healthy trees is being increasingly important and thereby also the need to manage this emerging pest species. This paper deals with quantifying the adult populations in the field in order to evaluate the potential performance of mass trapping as control method against C. welensii. We used a mark-recapture protocol using feeding traps, which was complemented with some nocturnal observations and additional laboratory studies. Research was conducted in the Cornalvo Natural Park (southwestern Spain) during two consecutive years (2008–2009). Data were analysed with classic closed population (CP) methods and Maximum Likelihood Spatially Explicit Capture-Recapture (ML SECR) detection models. The results strongly supported the potential success of mass trapping as control method for C. welensii, including a high trapping efficiency (70–81%), relatively low adult population density for a pest species (316 and 265 adults/ha in 2008 and 2009), movement pattern of flying adults and highly aggregated distribution of adults in trees with traps. We also found experimental evidence that most adults come to the traps close to emergence as showed body appearance, longevity estimates and female reproductive age at trapping time. We discuss the practical achievement of mass trapping as control method integrating behavioural and ecological perspectives and, though a large-scale field validation is still lacking, we conclude that mass trapping may be a potential tool to manage C. welensii populations in dehesa open woodlands.     

Effects of past growth trends and current water use strategies on Scots pine and pubescent oak drought sensitivity

Drought-induced decline is affecting Pinus sylvestris populations in southern Europe, with very little impact on the more drought-tolerant Quercus pubescens. Although multiple studies have investigated interspecific differences in water use and growth strategies, the link between these two processes and how they vary within drought-exposed populations remains poorly understood. Here, we analysed tree ring and sap flow data from P. sylvestris and Q. pubescens stands in the Pyrenees in order to (1) evaluate differences in climate–growth responses among species, (2) disentangle the role of past growth trends and water use strategies in individual trees drought sensitivity and (3) assess whether such intraspecific patterns vary between species. Both species have suffered recent climatic constraints related to increased aridity. However, the effects of past growth trends and current water use traits on drought sensitivity varied among them. Initially, fast-growing ‘drought-sensitive’ pines displayed a higher gas exchange potential but were more sensitive to evaporative demand and soil moisture. They also showed lower water use efficiency for growth (WUE_BAI) and current growth decline. In contrast, initially, slow-growing ‘drought-tolerant’ pines showed the opposite water use traits and currently maintain the highest growth rates. In comparison, neither current WUE_BAI nor recent growth trends varied across Q. pubescens climate–growth groups. Nonetheless, ‘drought-sensitive’ oaks showed the lowest gas exchange potential and the highest growth rates under milder conditions. Our results show a strong effect of past growth trends and current water use strategies on tree resilience to increased aridity, which is more evident in P. sylvestris.     

Trypanocidal activity of extracts and fractions of Bertholletia excelsa

Crude extracts and fractions of Bertholletia excelsa stem barks were tested for trypanocidal activity. Acetone and methanol extracts showed significant in vitro trypanocidal activity against trypomastigote form of Trypanosoma cruzi since in the concentration of 500 microg/ml, the parasites were reduced in 100% and 90.3% respectively, whereas the triterpene betulinic acid pure isolated from hexane extract presented 75.4%.