Coastal Sand Dunes

1. Medio Físico
1.1. CAPITULO 1. Historia y situación actual de la Reserva de la Biósfera Ría Lagartos
Cristóbal E. Cáceres G. Cantón y Rafael Robles de Benito.........................................................................14
1.2. CAPITULO 2. El medio físico: Clima, geoformas, suelos y agua
Francisco Bautista, Jorge Leirana, Yameli Aguilar, Carmen Delgado y Oscar Frausto................................21
1.3. CAPITULO 3. Estado de conservación de la vegetación
Sachiko Chiriguchi Murayama y Luis Salinas-Peba......................................................................................41
1.4. CAPITULO 4. Hidrocarburos en sedimentos recientes
Pedro F. Góngora-Góngora, Víctor M. Cobos-Gasca y Roberto C. Barrientos-Medina...............................68
2. Medio Biótico
2.1. CAPITULO 5. Estructura de la vegetación de la selva baja caducifolia y de la selva baja
inundable
Patricia Guadarrama, Luis Salinas-Peba y Silvia Castillo-Argüero..............................................................87
2.2. CAPITULO 6. Fenología de floración y visitantes florales de especies herbáceas
Víctor Parra-Tabla, Luis Abdala-Roberts Patricia Téllez, Nataly Celaya, Luis Salinas-Peba y Conchita
Alonso..........................................................................................................................................................105
2.3. CAPITULO 7. Tres especies de arbustos como “constructoras” de hábitat en el matorral
costero
Jorge L. Leirana Alcocer, Luisa A. Ríos Candila, Francisco Bautista, Jorge A. Navarro Alberto y Manuel B.
Crespo.........................................................................................................................................................123
2.4. CAPITULO 8. Respuestas ecofisiológicas de plantas cactáceas: Fijación de CO2,
productividad y supervivencia
J. Carlos Cervera Herrera, Raiza J. Castillo Argáez e Irving R. Vargas Solís..............................................140
2.5. CAPITULO 9. Hongos micorrizógenos: organismos clave para la vegetación
José Ramos-Zapata, Patricia Guadarrama, Laura Hernández-Cuevas, Luís A. Salinas Escobar, Ángel
Patrón, Gema Galindo-Flores, Alejandro Kong-Luz, Guadalupe Santiago-Martínez y Rosabel Juárez
Barradas.....................................................................................................................................................160
3. Biodiversidad
3.1. CAPITULO 10. Diversidad de insectos parasitoides: avispas Ichneumonidae
Alejandra González-Moreno, Hugo Delfín-González y Santiago Bordera...................................................179
3.2. CAPITULO 11. Riqueza y abundancia de los murciélagos en las selvas secas
Celia Sélem-Salas y Juan Tun-Garrido........................................................................................................195
3.3. CAPITULO 12. Las poblaciones de cocodrilianos (Crocodylus acutus y C. moreletti)
Mitzi A. Olvera-Morales, Roberto C. Barrientos-Medina, José R. Cedeño-Vázquez, Jorge A.
Navarro- Alberto y Felipe G. Be-Estrella.....................................................................................................207
3.4. CAPITULO 13. Los peces continentales
Roberto C. Barrientos-Medina, Alejandra Aguillón-Negreros y Lizbeth Chumba-Segura..........................219
4. Interacciones Bióticas
4.1. CAPITULO 14. Visitantes florales y redes de interacción planta–polinizador
María José Campos Navarrete, Rommel Moo Aldana, José Ramos Zapata y Víctor Parra Tabla.............231
4.2. CAPITULO 15. Interacciones planta-colibrí en la duna costera
Pamela Medina y Víctor Parra-Tabla...........................................................................................................249
4.3. CAPITULO 16. Interacción planta-hongos benéficos en la restauración de la vegetación de
duna costera
José A. Ramos-Zapata, Ricardo Aldana Blanco y Patricia Guadarrama Chávez.......................................266
4.4. CAPITULO 17. Murciélagos frugívoros y polinectarívoros
Celia Selem-Salas, Juan Tun-Garrido J, Lorena Tzab-Hernández y Miguel Peña-Tun...............................281

This paper examines the multi-decadal evolution of a foredune and backshore river complex on a wave-dominated, drift-aligned coast at Wickaninnish Bay on southwestern Vancouver Island, British Columbia, Canada. Local shoreline positions are generally prograding seaward as fast as + 1.46 m a− 1 in response to rapid regional tectonic uplift and positive onshore sediment budgets. The northern end of the foredune system has extended rapidly alongshore in response to net northward littoral drift. Despite these net accretional responses, the beach–dune system experiences relatively frequent (return interval ~ 1.53 years) erosive events when total water levels exceed a local erosional threshold elevation of 5.5 m above regional chart datum. Geomorphic recovery of the beach–dune system from erosive events is usually rapid (i.e., within a year) by way of high onshore sand transport and aeolian delivery to the upper beach. This response is complicated locally, however, by the influence of a backshore river that alters spatial–temporal patterns of both intertidal and supratidal erosion and deposition.

Historic landscape changes and rates of shoreline positional change are derived from several years of aerial photography (1973, 1996, 2007, 2009, 2012) using the USGS Digital Shoreline Analysis System (DSAS). Significant volumetric changes are also estimated from aerial LiDAR-derived DEMs in 2005, 2009 and 2012, and related morphodynamics are interpreted using a statistically constrained geomorphic change detection method. Results suggest that supratidal bar development, overwash deposition and aeolian deposition on a low-lying supratidal platform, combined with alongshore extension of the foredune complex, is forcing Sandhill Creek to migrate northward in the direction of beach drift. In response, the river actively erodes (− 1.24 m a− 1) a bluff system landward of the channel, which generates substantial sediment volumes (− 0.137 m3 m− 2 a− 1) that feed a large intertidal braided channel and delta system. These local responses provide context for a conceptual model of the evolution of a wave-dominated, drift-aligned beach–foredune system that interacts with a backshore river. This model may provide useful information to local park managers as erosion and sedimentation hazards threaten visitor safety and park infrastructure.

Located at the crossroads between Africa and Eurasia, Arabia occupies a pivotal position for human migration and dispersal during the Late Pleistocene. Deducing the timing of humid and arid phases is critical to understanding when the Rub' al-Khali desert acted as a barrier to human movement and settlement. Recent geological mapping in the northern part of the Rub' al-Khali has enabled the Qua- ternary history of the region to be put into a regional stratigraphical framework. In addition to the active dunes, two significant palaeodune sequences have been identified. Dating of key sections has enabled a chronology of dune accretion and stabilisation to be determined. In addition, previously published optically stimulated luminescence (OSL) dates have been put in their proper stratigraphical context, from which a record of Late Pleistocene dune activity can be constructed. The results indicate the record of dune activity in the northern Rub' al-Khali is preservation limited and is synchronous with humid events driven by the incursion of the Indian Ocean monsoon.

Costa da Caparica, located south of Lisbon, has been since the 1960s the favourite beach of the population of the Portuguese capital. The bridge over the Tagus river (1966), connecting the two margins, has facilitated the access to that wide beach of sand and dunes. Due to its natural features and proximity to Lisbon, Caparica become a highly populated area, where different social and economic activities compete for the use of the available space, increasing pressure upon the local ecosystems. The situation is even more problematic, because that littoral has been deeply affected by coastal erosion from the 1950s onwards. Authorities have been dealing with the issue using groynes and artificial beach nourishments. Since 2015, the Municipality of Almada is investing in the rehabilitation of the dunes of the beach of S. João, placing fences to retain the sand and planting vegetation. This programme is particularly interesting from a coastal management history point of view, because these dunes have been the object of many interventions with different purposes, but what was done and why is not very well known. The aim of this article is therefore to present the results of a historical research about human intervention in Costa da Caparica and, particularly at S. João beach, starting in the 19th century, with the first dunes' survey, the afforestation experiences and the construction of a drainage system. This paper offers a long-term perspective on the socio-evolution of these hybrid environments. Results and discussion show how dunes were trimmed by the works carried out and the reasons that laid beneath these. Revealing the ideas and values, the social, economic and political pressures, that across the years and within the same time period, shaped management strategies and landscapes.

Teri sands from the southeast coast of Tamil Nadu were examined by magnetic methods, including magnetic susceptibility measurements, acquisition of isothermal remanent magnetization, and geochemistry. Four sections were excavated up to 5-7m with three inland deposits (KCV, SKM and TPV) and one near coastal (THOP). Magnetic parameters show the important contribution of hematite structures to the studied sands, namely in SKM and KCV samples. In TPV and THOP samples, magnetic parameters indicate the presence of multidomain magnetite or mixed mineral contents of magnetite and antiferromagnetic minerals. SKM samples present the highest quantity of hematite and smallest quantity of magnetite, as is shown by the highest values of HIRM% and smallest of S-300 and SIRM. The positive correlation between c with clay in TPV, THOP and KCV sections indicates that the clay matrix carries magnetic susceptibility. In SKM, magnetic susceptibility is due to the silt fraction. Presence of magnetite in THOP and TPV sections is probably of oceanic origin carried by strong offshore winds. In SKM the wet environments due to cultivation (associated with a arid climate) may contribute to the prevalence of the necessary conditions for the dominant presence of hematite.

Much of the Dutch coast has been subject to structural erosion. From 1990 onward, sand nourishments have been used under a government policy of dynamic preservation. Annual monitoring and field inspections show that the structural erosion has decreased or even turned into coastal progradation after 1990. The monitoring data concern only morphodynamics and thus supply limited information on system-related geological processes driving the observed changes. Recently acquired ground-penetrating radar (GPR) data help establish the origin of sedimentary elements within the beach-foredune area, determine their decadal-scale preservation potential under the present nourishment policy, and demonstrate temporal and spatial accretion/erosion variability along nourished coasts. GPR images from an onnourished retrograding barrier section show historical storm surge deposits within the eroding foredune and accumulations of natural eolian sediment farther landward. GPR images from a heavily nourished, prograding site show that the accreted foredune and beach consist of nourishment embankments (20%), wind-blown units derived from nourished sand (70%), and progradational beach deposits (10%). The net volume of accretion at this site is approximately 200 m3 /m. Remarkably, almost all sand nourished before 2000 has been washed away, except for embankments constructed in 1990. Analysis of meteorological data suggests that 1999 storm surges are responsible for this erosion. The relative longevity of post-2000 nourishments can be attributed to a combination of shoreface nourishment and favorable meteorological conditions. During a storm surge in 2007, water-lain embankments proved to be more resistant against wave erosion than nourished sand redistributed by wind, indicating the importance of grain size, roundness and packing in the durability of nourishments.

The building of dunes and sand drifts along the European coastline are generally related to climatic variability and sea-level fluctuation. The last phase of dunes formation in southwestern Europe coincides with the Little Ice Age (LIA) period characterized by pronounced climate variability. Historical sources retrieved from archives also report sand-drift events along the Portuguese coast. The sand invaded many agricultural fields, and settlements, forcing the inhabitants to move elsewhere. The article explores the temporal relationships between sand drift occurrences and climate, as a principal trigger for coastal dune migration. We used historical sources about sand-drift events as documentary proxies to infer the past climate variability on the Portuguese coast. Three spatial scales of climate variability were considered: i) the global climatic variability induced by the cold abrupt events over the last Millennium (LIA); ii) the regional (mesoscale) climate variability (NAO index), and iii) the local climate variability (extreme meteorological events). The paleoclimatic interpretation indicates that drifts in Portugal are related to both NAO modes, providing new insights into coastal dunes dynamics, as a response to natural drivers. However, the analysis of human activity on the coast also allowed us to better understand the relation of the local populations with their environments, highlighting those anthropogenic actions caused an additional disturbance on coastal dune dynamics.

Successful germination protocols for the following six dune species are presented: Centaurea sphaerocephala subsp. sphaerocephala, Jacobaea maritima subsp. maritima, Matthiola sinuata, Medicago marina, Pancratium maritimum, and Silene canescens. Seeds were collected in sand dunes along the Tyrrhenian coasts in south Tuscany and north Latium (central Italy). The germination ability was tested at the Tuscia Germplasm Bank (BGT) at six constant temperatures (from 5 to 30°C), under both light (with a 12/12h pho-toperiod) and total dark. Our results show a high germination ability and germination rate for the tested species.

Airflow dynamics over beach-foredune systems can be complex. Although a great deal is known about the effects of topographic forcing and vegetation cover on wind-field modification, the role of large woody debris (LWD) as a roughness element and modifier of boundary layer flow is relatively understudied. Individual pieces of LWD are non-porous elements that impose bluff body effects and induce secondary flow circulation that varies with size, density, and arrangement. Large assemblages of LWD are common on beaches near forested watersheds and collectively have a degree of porosity that increases aerodynamic roughness in ways that are not fully understood. A field study on a mesotidal sandy beach with a scarped foredune (Calvert Island, British Columbia, Canada) shows that LWD influences flow patterns and turbulence levels. Overall mean and fluctuating energy decline as flow transitions across LWD, while mean energy is converted to turbulent energy. Such flow alterations have implications for sand transport pathways and resulting sedimentation patterns, primarily by inducing deposition within the LWD matrix.

Costa da Caparica, located south of Lisbon, has been since the 1960s the favourite beach of the population of the Portuguese capital. The bridge over the Tagus river (1966), connecting the two margins, has facilitated the access to that wide beach of sand and dunes. Due to its natural features and proximity to Lisbon, Caparica become a highly populated area, where different social and economic activities compete for the use of the available space, increasing pressure upon the local ecosystems. The situation is even more problematic, because that littoral has been deeply affected by coastal erosion from the 1950s onwards. Authorities have been dealing with the issue using groynes and artificial beach nourishments. Since 2015, the Municipality of Almada is investing in the rehabilitation of the dunes of the beach of S. João, placing fences to retain the sand and planting vegetation. This programme is particularly interesting from a coastal management history point of view, because the...

Coastal dune ecosystems are characterized by a strong relationship between abiotic and biotic factors. The aim of the study is to identify the abiotic factors that mostly affect distribution and composition of plant dune communities along the coast-to-inland gradient, focusing the attention on sediment grain-size parameters, mineralogy, and dune morphology. The research was carried out on two coastal dune systems belonging to protected areas in the Mediterranean Basin, specifically in Northern and Southern Tuscany (Italy). Grain-size analysis, X-ray powder diffraction, topographic surveys, and floristic data recording were carried out along 11 transects perpendicular to the shoreline; the portion of the beach investigated is comprised within the foreshore and the backdune area. The analyses revealed some differences between the two coastal dune systems in terms of sediment parameters, mineralogy, and dune topography. The differences are mainly ascribed to the
physical characteristics of the sites where the surveys were carried out. These data were matched with those provided by the vegetation sampling and then statistically processed by means of methods such as the Canonical Correlation Analysis (CCA), which showed that the mean grain-size is the most important abiotic factor that influences the composition of these coastal plant communities. These results might be considered to improve and optimize management and
conservation programs for these ecosystems, since nowadays artificial dune reconstruction is a practice frequently used as a form of coastal protection.

Mediterranean coastal dunes are dynamic and eterogeneous ecosystems characterised by a strong interaction between abiotic and biotic factors. The present study aimed to adopt a multidisciplinary approach - integrating data on dune  orphology, sediment texture and soil parameters as well as shoreline trend - in order to define which are the abiotic actors that most affect the distribution and composition of Mediterranean plant dune communities. The study was carried out in two protected areas, located in central Italy, subjected to different shoreline trends in recent years. 75 lots were identified along eleven randomly positioned cross-shore transects, starting from the beach continuing up to the plant communities of the backdunes. In each plot floristic and environmental data - such as distance to the coastline, plot altitude, inclination, shoreline trend, mean grain-size, sorting, pH, conductivity and organic matter concentration - were collected. The analyses revealed significant changes of vegetational cover, dune morphology and geopedological features along the coast-to-inland gradient. Relationships between vegetation composition and environmental factors were investigated through Canonical Correspondence Analysis (CCA). Four factors - distance to the coastline, mean grain-size, shoreline trend and organic matter e were found to be closely correlated with the floristic composition of plant communities. Finally, soil properties were highlighted as the most determinant factors of community zonation in these Mediterranean coastal dune ecosystems. These results could be taken into account by local managers in conservation actions such as protecting the eroding foredunes as well as in artificial dune reconstructions.