EARLY TO RISE MAKES A PLANT HEALTHY, WEALTHY, AND WISE.

Seedling emergence time is a crucial event in the life cycle of a plant, determining its fitness via different components including survival, growth, and fecundity. Precocious emergents usually survive, grow, and/or reproduce earlier in the life cycle, but for perennials it is unknown whether these benefits are maintained throughout the life of the plant. Here, we examine for the first time whether fitness benefits due to the early emergence of perennial plants are perpetuated or vanish with time. For nine years, in a Mediterranean gorse community, we followed the fate of 2118 seedlings belonging to the four dominant woody species. We estimated phenotypic selection gradients on emergence time for three fitness components (survival, growth, and fecundity), under two experimentally simulated scenarios (fire and fire + erosion), at two different times in the life of the plant (3 and 9 years). Fire and erosion represent two potential selective forces constraining the temporal window of seedling emergence in Mediterranean habitats. All the species exhibited selection for early emergence, but through different fitness components. Directional selection favoring early emergence via survival in both fire scenarios was detected in the two Cistaceae species (Helianthemum marifolium and Cistus albidus), in which precocious emergents had higher fitness values late in the life cycle (9 years). In contrast, Fabaceae species (Ononis fruticosa and Ulex parviflorus) were not selected for early emergence via survival. Early emergents of all species in both fire scenarios had higher fitness values through growth early in the life cycle; these benefits decreased slightly with time but remained statistically significant, except in H. marifolium. Finally, late fecundity was enhanced by early emergence in both fire scenarios in C. albidus and U. parviflorus but not in H. marifolium. In conclusion, benefits acquired by emerging early are perpetuated for at least nine years.

When, how and how much: Gender-specific resource-use strategies in the dioecious tree Juniperus thurifera.

BACKGROUND AND AIMS: In dioecious species male and female plants experience different selective pressures and often incur different reproductive costs. An increase in reproductive investment habitually results in a reduction of the resources available to other demands, such as vegetative growth. Tree-ring growth is an integrative measure that tracks vegetative investment through the plant's entire life span. This allows the study of gender-specific vegetative allocation strategies in dioecious tree species thoughout their life stages. METHODS: Standard dendrochronological procedures were used to measure tree-ring width. Analyses of time-series were made by means of General Mixed Models with correction of autocorrelated values by the use of an autoregressive covariance structure of order one. Bootstrapped correlation functions were used to study the relationship between climate and tree-ring width. KEY RESULTS: Male and female trees invest a similar amount of resources to ring growth during the early life stages of Juniperus thurifera. However, after reaching sexual maturity, tree-ring growth is reduced for both sexes. Furthermore, females experience a significantly stronger reduction in growth than males, which indicates a lower vegetative allocation in females. In addition, growth was positively correlated with precipitation from the current winter and spring in male trees but only to current spring precipitation in females. CONCLUSIONS: Once sexual maturity is achieved, tree rings grow proportionally more in males than in females. Differences in tree-ring growth between the genders could be a strategy to respond to different reproductive demands. Therefore, and responding to the questions of when, how and how much asked in the title, it is shown that male trees invest more resources to growth than female trees only after reaching sexual maturity, and they use these resources in a different temporal way.

Factors controlling seedling germination after fire in Mediterranean gorse shrublands. Implications for fire prescription.

In Western Mediterranean areas, fires are frequent in forests established on old croplands where woody resprouting species are scarce and post-fire regeneration is limited to obligate-seeder species, such as Mediterranean gorse (Ulex parviflorus), that accumulate a great deal of fine dry fuel, increasing the risk of other severe fires. Under these conditions, fuel control techniques are required in order to prevent fires of high intensity and severity and the subsequent economic and ecological damage. Prescribed fires present an alternative to fuel control, and recent studies demonstrate that, under optimum climatic conditions, fire-line intensity values fall within the limits of those recommended for fire prescription. However, a better understanding of the consequences of fire on the regeneration of vegetation is needed in order to evaluate the suitability of prescribed fires as a technique for fuel reduction in Mediterranean gorse ecosystems. This paper analyses the factors controlling seedling germination after fire to make an evaluation from an ecological perspective of whether fire prescription is a suitable technique for fuel control in mature Mediterranean gorse shrublands. The results show that small differences in the composition of vegetation play a decisive role in fire behaviour, and have a decisive influence on the system's capacity for regeneration. Fire severity is low in mixed Mediterranean gorse communities with a low continuity of dead fine fuel (including Cistus sp., Rosmarinus sp., etc.) and fire creates a wide range of microhabitats where seedling emergence is high. In contrast, where U. parviflorus is more dominant, fire severity is higher and the regeneration of vegetation could be hindered. Our conclusions suggest that detailed studies of the composition of plant communities are required in order to decide whether prescribed burning should be applied.

Factors influencing fire behaviour in shrublands of different stand ages and the implications for using prescribed burning to reduce wildfire risk.

Fire behaviour under experimental conditions is described in nine Mediterranean gorse shrublands ranging from 3-12 years of age with different fuel loads. Significant differences in the fire-line intensity, fuel load and rate of fire spread have been found to be related to the stage of development of the communities. Fire spread is correlated with fuel moisture using multiple regression techniques. Differences in fuel moisture between mature and young communities under moderate weather conditions have been found. The lower moisture content identified in the mature shrubland is due both to the decreasing moisture content of senescent shrubland in some species, mainly in live fractions of Ulex parviflorus Pour. fuel, and to a substantial increase in dead fuel fractions with low percentages of moisture content. The result is that the older the shrubland is, the greater will be the decrease in the total moisture content of the vegetation. In these moderate weather conditions, the fire intensity of the mature community was as high as the maximum intensity recommended for prescribed fires. This fact seems to indicate that, even under moderate conditions, prescribed burning as an alternative management tool in the mature shrubland must always take into account fuel control; on the other hand, this technique could be applied more easily when the shrubland is at an intermediate growth stage (4-5 years of age). Therefore, more frequent low-intensity prescribed fires are indicated to abate the risk of catastrophic fire.

Structure of (-)-1-phenylethylammonium hydrogen (+)-tartrate.

C8H12N+.C4H5O6-, Mr = 271.27, monoclinic, P21, a = 6.352 (2), b = 14.195 (5), c = 7.507 (2) A, beta = 107.08 (2) degrees, V = 647.0 (8) A3, Z = 2, Dx = 1.39 g cm-3, lambda (Mo K alpha) = 0.71069 A, mu (Mo K alpha) = 1.05 cm-1, F(000) = 288, T = 294 K, R = 0.037 for 941 observed reflections [F greater than 2 sigma (F)]. This (+)-tartrate structure is very similar to its meso-tartrate analogue. O(6) occupies an unusual antiperiplanar position relative to the carboxyl group. A strong hydrogen-bond network stabilizes the crystal packing.

Mortality risks of mentally retarded and mentally ill patients after a feeding gastrostomy.

Feeding gastrostomy procedures were performed on 9 mentally ill and 30 mentally retarded, institutionalized patients. The postoperative mortality was 0 percent (0/9) for the mentally ill and 13 percent (4/30) for the mentally retarded patients. Mortality within 1 year after the operation was 11 percent (1/9) for the mentally ill and 33 percent (10/30) for the retarded patients. This study revealed three important factors that affect mortality risks: the identification and elimination of a gastroesophageal reflux before surgery, the monitoring and improvement of the nutritional status both before and after surgery, and the evaluation and treatment of respiratory problems both before and after surgery. If care in these areas is improved, then the mortality risks for retarded patients will decrease.

Surgical management of acute diverticulitis in women.

The incidence of diverticular disease of the colon has increased during the course of this century. The management of diverticulitis has changed in many centers from a conservative medical approach to a more aggressive surgical one. The surgical technique has also evolved; primary resection and anastomosis is currently preferred after a standard bowel preparation. The authors reviewed the medical histories of 387 women who had undergone abdominal operation for acute diverticulitis at the Mayo Clinic during a recent 8-year period. Of the 387 patients, 71 (18.3%) had presented with a pelvic mass and 84 (21.7%) had the operation performed by a gynecologic surgeon. The preoperative evaluation, type of operation, morbidity, and mortality in the entire group and in the group managed by a gynecologic surgeon were studied and compared.