Organization for Economic Co-Operation and Development (OECD).

Phytoremediation is an emerging technology for the remediation of mine tailings, a global problem for which conventional remediation technologies are costly. There are two approaches to phytoremediation of mine tailings, phytoextraction and phytostabilization. Phytoextraction involves translocation of heavy metals from mine tailings to the plant shoot biomass followed by plant harvest, while phytostabilization focuses on establishing a vegetative cap that does not shoot accumulate metals but rather immobilizes metals within the tailings. Phytoextraction is currently limited by low rates of metal removal which is a combination of low biomass production and insufficiently high metal uptake into plant tissue. Phytostabilization is currently limited by a lack of knowledge of the minimum amendments required (e.g., compost, irrigation) to support long-term plant establishment. This review addresses both strategies within the context of two specific climate types: temperate and arid. In temperate environments, mine tailings are a source of metal leachates and acid mine drainage that contaminate nearby waterways. Mine tailings in arid regions are subject to eolian dispersion and water erosion. Examples of phytoremediation within each of these environments are discussed. Current research suggests that phytoextraction, due to high implementation costs and long time frames, will be limited to sites that have high land values and for which metal removal is required. Phytostabilization, due to lower costs and easier implementation, will be a more commonly used approach. Complete restoration of mining sites is an unlikely outcome for either approach.

Phytoremediation of mine tailings in temperate and arid environments

Report of the scientific committee.

Ecological processes and plant adaptations on coastal dunes

Tesis de ,aestria presentadas en la facultad de ciencia y tecnologia, Universidad Pedagogica Nacional.

Tesis de maestria

A classification is presented of community types found in the coastal sand dune systems along the Gulf coast and the Caribbean Sea of Mexico Twenty-eight dune systems were sampled along transects using the Braun-Blanquet approach A total of 4444 releves were subjected to agglomerative classification and table arrangement (program TABORD) Synoptic species values were calculated for the 396 clusters obtained They were arranged in two new data sets, one comprising the material from Tamaulipas and Veracruz and the other Yucatan and Quintana Roo These data sets were again subjected to classification and ordination (detrended correspondence analysis) programs Final community types are based on the basic clusters, 59 types for the Gulf area and 31 for the Caribbean Their geographical and ecological distribution is interpreted

Classification and ordination of coastal sand dune vegetation along the Gulf and Caribbean Sea of Mexico

Populations of arbuscular mycorrhizal fungi were estimated from spores associated with seven plant species in coastal dunes at El Socorro, near Ensenada, Baja California, during six months in 1992. The seasonal patterns of percent root colonization were also described in the same species during the wet season (January–March) and the dry season (April–July). Comparisons were made between the pioneer species (Abronia maritima) in the mobile dunes and six species (Abronia umbellata, Atriplex julacea, Camissonia californica, Haplopappus venetus, Helianthus niveus and Lotus spp.) in the fixed dunes. Mycorrhizal colonization in Abronia maritima was slight (<1%) and we observed few spores (<1/g soil). All of the species in the fixed dune formed mycorrhizae with up to 80% colonization in early summer, and no more than 4 spores/g soil by late summer. The highest percentages of total colonization and abundance of spores did not coincide temporally for any of the seven species, but the percentages were higher in summer than in spring. Arbuscules were more abundant when the soil was moist, and vesicles more abundant when it was dry.

Seasonality of mycorrhizae in coastal sand dunes of Baja California

An integrated index to evaluate recreational sand beaches (IBVI) was designed using descriptive beach indicators (BI), beach user’s perception (KI) and indicators of beach economic value (MI). This index was applied in five urban sandy beaches with similar physiographic features, but economically and socio-culturally different (Ensenada, Rosarito and Mazatlan in Mexico; Copacabana in Brazil; and Oceanside in Southern California in USA). According to the IBVI evaluation, Oceanside was the best beach, all values rating high, followed by Copacabana with high BI and KI but low MI. Mazatlan was rated medium, although user’s perception was high. Poorly developed beaches, such as Ensenada, were rated medium for BI, KI and low for MI. The IBVI value at Rosarito was rated mediume-low because both the BI and KI values were low. IBVI incorporates three visions for beach awards in one and can be useful to compare tourist sand beaches around the world.

Design of an Integrated Evaluation Index for Recreational Beaches

Four beaches that share physiographic characteristics (sandy, wide, and long) but differ in socioeconomic and cultural terms (three are located in northwestern Mexico and one in California, USA) were evaluated by beach users. Surveys (565) composed of 36 questions were handed out to beach users on weekends and holidays in 2005. The 25 questions that revealed the most information were selected by factor analysis and classified by cluster analysis. Beach users’ preferences were assigned a value by comparing the present survey results with the characteristics of an “ideal” recreational urban beach. Cluster analysis separated three groups of questions: (a) services and infrastructure, (b) recreational activities, and (c) beach conditions. Cluster linkage distance (r = 0.82, r = 0.78, r = 0.67) was used as a weight and multiplied by the value of beach descriptive factors. Mazatlan and Oceanside obtained the highest values because there are enough infrastructure and services; on the contrary, Ensenada and Rosarito were rated medium and low because infrastructure and services are lacking. The presently proposed method can contribute to improving current beach evaluations because the final score represents the beach users’ evaluation of the quality of the beach. The weight considered in the present study marks the beach users’ preferences among the studied beaches. Adding this weight to beach evaluation will contribute to more specific beach planning in which users’ perception is considered.

Ileana Espejel

Papers

Classification and ordination of coastal sand dune vegetation along the Gulf and Caribbean Sea of Mexico

Seasonality of mycorrhizae in coastal sand dunes of Baja California

Design of an Integrated Evaluation Index for Recreational Beaches

Users' perception as a tool to improve urban beach planning and management.

Contextual factors influencing sustainable fisheries in Mexico