Juan B. Gallego-Fernández

Plant functional types in coastal foredunes in relation to environmental stress and disturbance

The foredune vegetation in the Gulf of Cadiz (SW Spain, S Portugal) was studied by means of morphological characters and functional traits of plants. The 55 vascular species recorded in the area were classified into three func- tional types: Type I consists mainly of winter annuals of moderate size with soft leaves, showing no presumed adapta- tions to the dune environment. Plants of Type II are mostly perennials with a below-ground spreading root network and leaves with presumed adaptations to coastal environmental stress. Type III includes plants mostly capable of being dis- persed by sea-water and of withstanding sand burial. In relatively unstable soil, Type II and Type III plants were found to be more abundant, their relative proportion depend- ing on the dominance of accretion/erosion processes. Increas- ing cover of Type I plants was associated with relatively more stable soils. The ratios in occurrences of the three types can be used as an indicator of foredune dynamics.

Assessment of coastal dune vulnerability to natural and anthropogenic disturbances along the Gulf of Mexico

Human population density is globally three times higher along the coasts than inland, and thus environmental impacts of human activities are greater in magnitude on coastal ecosystems such as beaches and dunes. Vulnerability assessment (the loss of capacity to return to the original dynamic state after system displacement) is thus necessary to evaluate the conservation status and determine the most relevant disturbance events. Twenty-six sites along 902 km of Gulf of Mexico coastline, varying in conservation status and sedimentary dynamics, were sampled. At each site a vulnerability index (VI) was calculated based on variables that described geomorphological condition, marine influence, aeolian influence, vegetation condition and human effects. Vulnerability was very variable along the coast and only 19% of the sampled locations (mostly in the central Gulf of Mexico) displayed low vulnerability. Cluster analyses of the values assigned to the checklists for each location grouped the studied sites into three, according to their VI values. Low vulnerability locations had abundant sediment supply and low human impact. Locations with medium to high VI were mostly affected by their natural geomorphological and marine features and had medium to intense human activities. Management strategies should consider the observed variability in vulnerability, the natural dynamics of these systems and the role of human activities and interests, in order to achieve adequate policies and establish well-informed priorities for integrated coastal zone management.

Small wetlands lost : a biological conservation hazard in Mediterranean landscapes

Summary In Spain, it is estimated that 60% of wetlands have disappeared in the last 50 years. The present study aimed to describe the relationships between loss of wetlands and land-use change in Azuaga County, Central-western Iberian Peninsula where during the period 1896‐1996, 94% of the original wetlands disappeared. Forest, scrub, holm oak dehesas and olive groves have become fragmented or disappeared completely, having been substituted by eucalyptus plantations in areas of low productivity and by dry cultivation of herbaceous crops, mainly cereals, in more productive areas. These substitutions have resulted in a homogeneous, coarse-grained landscape with low diversity and high dominance. The type of land-use has depended on the evolution of demographic processes, with high human immigration rates toward the end of the nineteenth century and beginning of the twentieth century, and high emigration rates during the 1960s and 1970s. The mechanization of agriculture and transition from closed to market economy in the second half of the twentieth century also played an essential role in the landscape changes described.

Environmental Filtering and Plant Functional Types on Mexican Foredunes along the Gulf of Mexico

Abstract: Ecological theory suggests that environmental filtering (the survival or elimination of species in the community in response to environmental constraints) is a key process in the species assemblages of communities. Environmental filters, such as sand movement and soil salinity in coastal dunes and beaches, may result in shared ecological tolerances and functional types, independently of phylogenetic and evolutionary history. In 19 beach—foredune sites located along the coast of the Gulf of Mexico we studied plant functional composition and diversity of vascular plants. Functional groups were determined with a classification analysis. Relative importance values and diversity indices of species and functional groups were compared with ANOVA tests. We distinguished 5 groups: a group of species tolerant to soil salinity and burial, most abundant on accreting beaches; a group of species tolerant only to burial, which were abundant on all coasts; and 3 groups that lacked specific responses to burial and soil salinity and were most abundant on stable and erosive coasts. Accreting foredunes showed the lowest species richness and functional diversity, because only a few species were tolerant to burial and soil salinity. In the foredune environment, sediment dynamics and geomorphological processes act as environmental filters that largely determine the floristic and functional composition of the community.

Andalusia, Spain: An Assessment of Coastal Scenery

Abstract The 1101 km length of the Andalusian coast (Spain) was assessed for coastal scenery at 45 specific locations. Selected areas covered resort (3), urban (19), village (8), rural (10) and remote (5) bathing areas. Scenery was analyzed for physical and human parameters via 26 selected parameters. These parameters were obtained by interviews of >500 people on European beaches. Each parameter was assessed via a one-to-five-point attribute scale, which essentially ranged from presence/absence or poor quality (1), to excellent/outstanding (5). Results were subsequently weighted by interviewing >600 bathing area users (not all 26 parameters have equal weight) and subjected to fuzzy logic mathematics in order to reduce recorder subjectivity. High weighted averages for attributes 4 and 5 (excellent/outstanding) reflected high scenic quality, vice versa for attributes 1 and 2. Sites were classified into five classes ranging from Class 1 sites having top grade scenery to Class 5, poor scenery. Seven sites each were found in Classes 1 and 2; 10 sites each in Classes 3 and 5; 11 sites in Class 4. The finest coastal scenery was found in remote areas whilst urban areas scored mainly as Class 3 or 4. Three out of the ten rural sites had Class 3 and 4 values assigned them whereas the rest scored as Class 1 and 2; village sites invariably had scores within Class 3 and 4. Of the three resort sites investigated, one scored as a Class 1 site, the others as Class 3.

Coastal Dunes: Human Impact and Need for Restoration

A large proportion of the world population lives at or near the coast, which results in high impact and degradation of coastal ecosystems, such as the beach and coastal dunes. These ecosystems are particularly threatened by the impact of human activities because of the increasing demand of sun and sand tourism throughout the world. Because of this increase, conservation activities and restoration efforts will become more and more relevant. In spite of the urgent need for restoration, there are very few books focused on coastal dune restoration that cover a wide variety of coastal dune systems from different latitudes, including tropical and temperate dunes. In this book we have put together a set of restoration activities performed in different parts of the world. The goal was to gather information on state-of-the-art studies on the restoration of coastal sand dunes, covering a wide variety of landforms and approaches that can be of assistance in future coastal dune restoration projects. Different coastal land forms are included in this set of studies, such as foredunes, slacks/swales/deflation basins and plains, blowouts, parabolics, and transgressive dunefields. We follow a broad definition of “restoration,” which includes any effort to restore the original functionality of the previously existing ecosystem, but also efforts at rehabilitation, reclamation, and even designing ecosystems in drastically altered sites (such as after mining activities). The diverse array of contributions will hopefully stimulate further research that will lead to a better understanding of the actions required for improving restoration strategies.

The Contribution of Endozoochory to the Colonization and Vegetation Composition of Recently Formed Sand Coastal Dunes

The objective of this study was to determine whether endozoochory contributes to the dispersal and colonization of plant species in recently formed coastal dunes. At least 5.7% of species present in the study area are being dispersed by wild rabbits (Oryctolagus cuniculus L.). Most dispersed species are perennial herbs with small seeds size. The continuous input of seeds through rabbit feces into newly created areas would ensure the constant arrival of seeds and would facilitate colonization. Therefore, endozoochorous dispersal may play a relevant role for the structure and composition of dune plant communities.

The Coasts and Their Costs

Sandy beaches and coastal dunes throughout the world are threatened by human encroachment, and as they are lost, so are the ecosystem services provided by them. Because the economic value of ecosystem services has seldom been assessed, the ecological and socioeconomic consequences of the degradation or destruction of beaches and coastal dunes remain largely unknown. We performed an intensive literature review and found only 18 studies in which ecosystem services from the beach and coastal dunes had been analyzed and their economic value calculated. Recreation, cultural, and aesthetic ecosystem services were those most widely studied and with the highest values. Protection has also been studied, but, surprisingly, the economic value of this ecosystem service assigned by society was smaller. Restoration of coastal dunes is becoming an increasingly necessary and increasingly expensive activity. The activities involved in restoration actions are quite diverse, although there are three goals: restoring natural dynamics, recreational/aesthetic, and protective. Removal of unwanted vegetation seems to be amongst the most expensive restoration activities. The paradox in current development trends on beaches and coastal dunes is that the coasts are over-exploited, but, by doing this, the ecosystem services that we value the most and that drive exploitation trends (recreation, aesthetic, and protection) are degraded or lost. This dead-end situation is the result of ecosystem services not being considered in the decision-making process, and a few ecosystem services being over-exploited while others are ignored. Evidence shows that, before investing in coastal dune restoration, natural ecosystems should be preserved in their own integrity, with the additional benefits that they provide to society. Economically, socially, and ecologically, conservation is a better choice than degradation followed by restoration.

Coastal Dune Restoration: Trends and Perspectives

Sandy coasts are distributed worldwide and they are all heterogeneous ecosystems in terms of morphology, vegetation and dynamics. Psammophytes are common in these environments. Besides these widespread attributes, sandy beaches and coastal dunes also share the intense impact of humans. Because of their privileged location at the coast, they are preferred sites for urban and maritime development, destinations for tourists, and locations for many other human activities. Thus, over the years (but especially during the last few decades) many of the previously natural dunescapes have been lost to urban, tourist, and industrial developments. Furthermore, a recurring problem of many coastal dune systems is over-stabilization, which is mostly the result of human actions. The urgent need to preserve the natural and valuable coastal dune remnants and, as much as possible, restore those that have been degraded, is evident. There are many different and contrasting actions that have been followed during restoration activities. Restoration actions have involved “soft” methods, such as sand fences, and “hard” methods, such as geotubes and herbicides. Also, restoration may lead not only to the stabilization of dunes, but also to the re-mobilization of sand. On an overcrowded planet where the coasts are ecosystems to which humans gravitate, conservation and restoration actions become exponentially important.

Multicriteria Analysis to Implement Actions Leading to Coastal Dune Restoration

This chapter explores the variables that can influence the success of beach and dune restoration, utilizing Analytic Hierarchy Process (AHP) and the contributions of a multidisciplinary panel of recognized experts that includes ecologists, geomorphologists, anthropologists, and specialists in the restoration of coastal dunes. The criteria selected to represent the beach–dune system were chosen taking into consideration their influence on the success or failure of ecological restoration. Three levels were considered: criteria, subcriteria, and indicators. The first consists of four criteria (degree of degradation, factors that cause stress to the system, facilitators and elements that assist prioritization). The second level has ten subcriteria: morphological degradation and system fragmentation; degradation of vegetation; internal stress factors; external stress factors; abiotic factors that facilitate restoration; biotic factors that facilitate restoration; presence of species in any category of risk; proximity to protected areas; increased occurrence of floods; ecosystem services at risk). The third level consists of 38 indicators (e.g., evidence of damage by trampling of vegetation, visitor pressure, infrastructure affecting sediment dynamics, proximity of sources of propagules that can be used in restoration, among others). The relative importance of the elements of each level was calculated by the panel of experts. In a range from 0 to 1, the highest weighting (0.37) was assigned to the criterion “facilitators”. This term refers to the existence of biotic and abiotic elements necessary for restoration to take place. This criterion also includes 12 indicators (availability of pioneer plants; presence of tolerant native plant species; availability of space, orientation of the coast with respect to the waves; aeolian transport; sediment size; presence of nearby sediment sources; presence of infrastructure that alters wind dynamics, among others). The lowest weighting (0.15) was assigned to the criterion “elements that assist prioritization”. This criterion refers to those elements that are priorities for mankind that attract public attention as well as financial investment for the restoration of a given site and includes indicators such as proximity to protected areas, proximity to cultural sites and tourist areas, as well as measured ecosystem services such as the presence of human interests that are at risk of disappearing because of hurricanes or under rising sea, an abundance of hotels, and the occurrence of floods. Multi-criteria analysis is useful for making complex decisions, such as the choice of beaches and dunes for restoration. This is because it allows the problem to be addressed in an orderly manner, chooses the most representative criteria as well as assigning weighting. Furthermore, the use of this analysis allowed us to take a range of opinions into account through the contributions of a panel of experts. Inclusion of such a panel saves time while giving credibility to the decisions taken.