No abstract

The development of second‐growth forest after abandonment of agricultural fields in tropical montane cloud forest (TMCF) areas is common in southern Mexico, but little is known about how such changes affect soil properties. We evaluated the changes in soil properties at the 0‐ to 20‐ and 20‐ to 40‐cm depths during this conversion in three chronosequences, each composed of a cornfield, and adjacent forests of ≈15, ≈45, ≈75, and ≥ 100 yr after abandonment at El Rincón, Oaxaca, Mexico. All studied soils were acidic, rich in organic C and total nitrogen (TN), and had low levels of plant‐available P, exchangeable Ca, Mg, Na, and K, and high levels of exchangeable Al. Most of the soil properties analyzed changed significantly with the age after abandonment, but in most cases the patterns of response varied with the chronosequence, usually ≈15 to 45 yr after abandonment. In all chronosequences, soil pH and N/P ratio decreased, and the thickness of the O horizon increased, during the first 100 yr of forest development. The highest rates of soil C sequestration and the highest drop in exchangeable K, Mg, and Ca concentrations took place the first 15 yr of forest development. Most of soil changes can be associated with nutrient retention by vegetation and litter, the concentration of exchangeable Al in soil, and the role of soil pH in mineralization rates, ion solubility, and rock weathering. The different patterns of response found among chronosequences illustrate the importance of having replicates before making general statements about changes in soil properties after disturbance.

ABSTRACT. Forest Landscape Restoration (FLR) involves the ecological restoration of degraded forest landscapes, with the aim of benefiting both biodiversity and human well-being. We first identify four fundamental principles of FLR, based on previous definitions. We then critically evaluate the application of these principles in practice, based on the experience gained during an international, collaborative research project conducted in six dry forest landscapes of Latin America. Research highlighted the potential for FLR; tree species of high socioeconomic value were identified in all study areas, and strong dependence of local communities on forest resources was widely encountered, particularly for fuelwood. We demonstrated that FLR can be achieved through both passive and active restoration approaches, and can be cost-effective if the increased provision of ecosystem services is taken into account. These results therefore highlight the potential for FLR, and the positive contribution that it could make to sustainable development. However, we also encountered a number of challenges to FLR implementation, including the difficulty of achieving strong engagement in FLR activities among local stakeholders, lack of capacity for community-led initiatives, and the lack of an appropriate institutional and regulatory environment to support restoration activities. Successful implementation of FLR will require new collaborative alliances among stakeholders, empowerment and capacity building of local communities to enable them to fully engage with restoration activities, and an enabling public policy context to enable local people to be active participants in the decision making process.

A pressing question that arises during the planning of an ecological restoration process is: where to restore first? Answering this question is a complex task; it requires a multidimensional approach to consider economic constrains and the preferences of stakeholders. Being the problem of spatial nature, it may be explored effectively through Multicriteria Decision Analysis (MCDA) performed in a Geographical Information System (GIS) environment. The proposed approach is based on the definition and weighting of multiple criteria for evaluating land suitability. An MCDA-based methodology was used to identify priority areas for Forest Landscape Restoration in the Upper Mixtec region, Oaxaca (Mexico), one of the most degraded areas of Latin America. Socioeconomic and environmental criteria were selected and evaluated. The opinions of four different stakeholder groups were considered: general public, academic, Non-governmental organizations (NGOs) and governmental officers. The preferences of these groups were spatially modeled to identify their priorities. The final result was a map that identifies the most preferable sites for restoration, where resources and efforts should be concentrated. MCDA proved to be a very useful tool in collective planning, when alternative sites have to be identified and prioritized to guide the restoration work. OPEN ACCESSSustainability 2014, 6 936

I assessed the relationship between the level of inbreeding, F, and fitness, and the effects of nonmaternal and maternal components of inbreeding on fitness in Phacelia dubia. I conducted two generations of controlled crosses and tested the performance of the F 2 progeny in field and artificial conditions covering the whole life cycle. Inbreeding significantly decreased the individual contribution of seeds to the next generation in the field, but this decrease apparently is not enough to explain the maintenance of gynodioecy. The inbred progeny contributes significantly to the population genetic structure of P. dubia. Fitness estimates and fitness components tended to decrease, usually monotonically, with F. However, nonmonotonic relationships were found in male fitness components and, in some families, in fitness estimates, seed production per fruit, and establishment. Most of the inbreeding depression takes place at the level of seed establishment in the field, but, in artificial conditions the effects of inbreeding were similar at fecundity and establishment. I studied maternal and nonmaternal components of inbreeding by testing the effects of the relatedness of maternal grandparents and parents on the performance of the progeny. Both components affected fitness. Inbreeding depression was conditioned by the level of inbreeding of the maternal plant, but this interaction varied at different fitness components. Also, the magnitude and even the direction of the relationship between fitness and F changed as a result of the combined effects of maternal and nonmaternal components of inbreeding. Such interactions can render convex or concave fitness functions, giving in the latter case the appearance of a false purging. Maternal effects of inbreeding can result from several processes: maternal investment perhaps with serial adjustments during seed development, purging of recessive deleterious genes, and nucleocytoplasmic interactions. These results illustrate the importance of maternal effects of inbreeding, and the complex effects of inbreeding on fitness. A full understanding of the fitness consequences of inbreeding and, therefore, their potential implications in the evolution of breeding systems, should take into account male and female components as well as trans generational effects in the context of the particular environment in which fitness is evaluated.