Potential pollen production, viability and germination were studied in the most important species... more Potential pollen production, viability and germination were studied in the most important species of Quercus in the mountains of Có rdoba to determine the contribution of each species to the total amount of airborne pollen. The results were compared over two consecutive years with different rainfall patterns. The viability of pollen grains was determined at anther opening, and during the pollination period, in order to determine potential pollination capacity. Results indicated that there were differences in the number of pollen grains produced by stamen in the four species. Equally, there were differences in the number of flowers among the species, being Q. suber the species with higher number of catkins groups and flowers per individual tree. Total pollen production per tree can be summarized in the following proportion: 1: 3: 3: 6 (Q. coccifera, Q. ilex ssp. ballota, Q. faginea and Q. suber). Potential pollen viability was estimated using the Fluorochromatic Reaction (FCR) and a germination assay. The results have shown that Quercus potential pollen viability is high and declines slowly with time. Q. coccifera was the species with the highest percentage of germination, with Q. suber being the lowest.
& Key message Composite logistic regression models simulating the potential effect of global clim... more & Key message Composite logistic regression models simulating the potential effect of global climate change on forests dynamics in the southern Iberian Peninsula identify Holm oak [Quercus ilex subsp. ballota (Desf.) Samp.] and Aleppo pine (Pinus halepensis Mill.) as the chief beneficiaries of the anticipated environmental shifts, whereas other oak species and conifers suffer a decline. & Context The ten most important tree species (five oaks and five conifers) in Southern Spain were selected for the study. The study area, corresponding to the region of Andalusia, is located in an interesting position between Central European and North African climates. The territory also exhibits the most extreme patterns of rainfall in the Iberian Peninsula. & Aims This study aims to model the potential distribution of the ten species in response to climate change, in several time periods, including the present and two future twenty-first century dates. & Methods The potential distributions within the different scenarios were simulated using logistic regression techniques based on a set of 19 climate variables from the WorldClim 1.4 project. The scenarios were drawn from the RCP 2.6 and 6.0 in the CCSM4 Global Circulation Model. The resolution of the output maps was 30 arc-seconds. & Results The simulation predicted increased distribution areas for Q. ilex and P. halepensis under the four future scenarios as compared to present. The eight remaining taxa suffered a severe retraction in potential distribution. & Conclusion Global climate change is likely to have a significant impact on forest dynamics in southern Spain. Only two species would benefit to the detriment of the others. Logistic Regression is identified as a robust method for carrying out management and conservation programmes.
Climate change models predict an increase in aridity in many parts of the world for the twenty-fi... more Climate change models predict an increase in aridity in many parts of the world for the twenty-first century, which is likely to be more intense in the Mediterranean basin than in other regions. This study addresses the potential distribution of three Mediterranean pine species (Pinus pinea L., P. halepensis Mill. and P. pinaster Aiton) in southern Spain in response to the forecast increased aridity. Pines constitute a useful source of various types of raw materials, which has led to their increasing introduction around the world. The study was based on ecological niche modelling using multinomial logistic regression, over an area spanning about 8.7 million ha in the south of Spain. In total, 11 explanatory variables were included, drawing on measurements made at high resolution (200 m). Four different periods were studied: the reference period (1961-2000), early twenty-first century (2011-2040), middle twenty-first century (2041-2070) and late twenty-first century (2071-2100). Future time slices were analysed in three different scenarios: B1, A1b and A2 in the CNCM3 general circulation model. The results predict a wider distribution for stone pine, which could expand its potential area in southern Spain. In contrast, Aleppo pine, and especially cluster pine, would reduce their present distribution, with cluster pine occupying higher altitude sites while low altitude populations diminished. The validation model enables accurate maps to be produced, representing powerful tools for afforestation/ reforestation programs in the future. Keywords Ecological niche modelling Á Global change Á Multinomial logistic regression Á Mediterranean pines Á Southern Spain Á Afforestation/reforestation programs Electronic supplementary material The online version of this article (
ABSTRACT Species which have suffered a contraction of their original distribution in a recent sta... more ABSTRACT Species which have suffered a contraction of their original distribution in a recent stage of the Earth’s history due to climate changes are termed climate relicts. In the Mediterranean basin, one of the most important hotspots of biodiversity in the world, many relict tree species remain in the mountain ranges. The Baetic range, situated in the southeast of the Iberian Peninsula, comprises three of these taxa (Pinus sylvestris L. var. nevadensis H. Christ, Pinus nigra Arnold subsp. salzmannii (Dunal) Franco and Abies pinsapo Boiss.), which grow in enclaves of suitable environmental conditions surrounded by an inhospitable regional climate. A high resolution predictive model for these species was carried out by making a grid of points with a resolution of 250 m, in which twelve explanatory variables were used: four topographical and eight climatic or bioclimatic. This grid also contains information about the presence/absence of the three species involved, which was used as the dependent variable. Then, a modeling process was carried out by means of binary logistic regression. According to the obtained model, climatic and bioclimatic independent variables (especially seasonal rainfall and mean temperatures) are more responsible for species distribution than topographic ones. The final potential distribution was found to be larger than the current one for all three species. This study is able to predict, with a high degree of accuracy, the potential distribution of the three species involved, and it is therefore proposed to implement reforestation programs at small-scale with high resolution (250 m). Other relict tree species from the Mediterranean basin or other places in the world could be modeled in the same way depending on measured variables.
• Biodiversity in this protected area was seriously affected. • The fire occurred under exception... more • Biodiversity in this protected area was seriously affected. • The fire occurred under exceptional synoptic and local meteorological conditions. • The fire reached El Arenosillo, and record-setting values of trace gases were measured. • The Doñana plume affected the western Mediterranean basin.
Taxus baccata is a relic declining species, especially at the southern margins of its natural dis... more Taxus baccata is a relic declining species, especially at the southern margins of its natural distribution, such as the Mediterranean and Irano-Turanian biogeographic regions. On the Island of Sardinia, it is still present in many mountain sites. This study identified 232 locations where yews grow. The species is indifferent to substrates, but prefers moist sites with northern aspects, and has elevation range is 695-1225 m a.s.l. To predict yew’s potential distribution in Sardinia, we collected data from the literature and field observations and applied the Maximum Entropy algorithm (MaxEnt). We used 202 field-based sites and 19 bioclimatic variables to model the potential distribution area under current climatic conditions. Annual precipitation, mean temperature of the warmest month and isothermality were the key drivers for the distribution of T. baccata in Sardinia. In terms of permutation importance, mean diurnal range and precipitation of the warmest quarter were the main environmental variables. The response curves showed that T. baccata prefers annual mean temperatures ranging from 8.65 to 12.55°C and annual mean precipitation from 770 to 1085 mm. Most potential suitable conditions were found in northern and central Sardinia. Using the Global Circulation Model, we also modelled future habitat suitability for T. baccata under two different scenarios, highlighting a substantial reduction of the habitat suitability for the species by the end of this century. This reduction is associated with climate change and poses an increasing concern about the future of the species and the priority habitat described in many parts of Sardinia.
This study examines 10 different taxa within the genus Abies identified in the circum-Mediterrane... more This study examines 10 different taxa within the genus Abies identified in the circum-Mediterranean area: A. alba, A. borisii-regis, A. cephalonica, A. cilicica, A. nebrodensis, A. nordmanniana subsp. equi-trojani, A. nordmanniana subsp. nordmanniana, A. numidica, A. pinsapo var. marocana and A. pinsapo var. pinsapo. We assess the potential distribution of these species in the Mediterranean Basin, most of Central-Northern Europe and Asia Minor through analysis of 8 bioclimatic variables. First, the potential distribution (suitability area) was calculated with Biomod2 package for R using 10 algorithms. Models were ensembled for the present period and then projected into two climate change scenarios (an intermediate and the most extreme) within two time slices (2041-2060 and 2081-2100) and two Global Circulation Models (GCMs). The analysis showed an increase in total suitable area under both forecasted scenarios. Abies spp. appeared to be resilient against climate change, showing a latitudinal and longitudinal migration trend in response to the loss of current habitats. A proposal of assisted migration (managed relocation) is suggested as an interesting alternative to guarantee the preservation of the most endangered species by promoting the establishment of new populations outside of their historical distribution area.
Predictions of an increase in mean temperatures and a widespread reduction in annual rainfall ove... more Predictions of an increase in mean temperatures and a widespread reduction in annual rainfall over the next few decades are consistent. Such drastic changes can have a serious, irreversible impact on the current distribution of trees and their ecosystems. Oaks are the most frequent trees in the better preserved areas of the Mediterranean basin; therefore, it is essential to understand potential shifts in their distribution for proper management and protection. The area studied in this work spans approximately 8.7 million hectares. The results obtained at 200 m resolution were subjected to logistic regression over four periods: current period (1961-2000), early twenty-first century (2011-2040), middle twenty-first century (2041-2070) and late twenty-first century (2071-2100). These periods were examined by using the CNCM3 model in an A1b scenario at 200 m resolution for the study area. Four of the five target species exhibited a narrower potential distribution in the twenty-first century. Cork oak and gall oak underwent a drastic potential reduction; on the other hand, Pyrenean oak and Algerian oak might find shelter at higher elevations. By exception, holm oak exhibited the opposite trend and was favoured by projected global warming. This projection is rather adverse for biodiversity and oak-dependent ecosystems. This study allowed an accurate prediction of the potential distribution of five different oak species and is therefore a promising, potentially effective tool for developing high-resolution reforestation programmes. Keywords Mediterranean oak trees Á Spatial modelling Á Global change Á Southern Spain Á Reforestation programmes Communicated by Joseph Paul Messina.
Page 1. Israel Journal of Plant Sciences Vol 49 2001 pp. 41^7 Catkin frost damage in Mediterranea... more Page 1. Israel Journal of Plant Sciences Vol 49 2001 pp. 41^7 Catkin frost damage in Mediterranean cork-oak {Quercus súber L.) Herminia García-Mozo,* Pablo J. Hidalgo, Carmen Galán, Maria Teresa Gómez-Casero, and ...
Sulfidic mine wastes have the potential to generate acid mine drainage (AMD) and release acid lea... more Sulfidic mine wastes have the potential to generate acid mine drainage (AMD) and release acid leachates containing high levels of iron, sulfate and potentially toxic elements (PTEs). Soils receiving AMD discharges are generally devoid of vegetation. Only a few metal-tolerant plant species can survive under such adverse soil conditions. This work investigates two plant species, Nicotiana glauca and Euphorbia segetalis, that have successfully colonized an AMD-impacted wetland area in south-western Spain. The uptake of PTEs from the soil by roots and their transfer and accumulation in the above-ground biomass were quantified. Results showed that these pioneer plants grew in patches of neutral soil within the wasteland despite the high concentrations of PTEs in the rhizosphere soil (up to: 613 mg kg−1 As, 18.7 mg kg−1 Cd, 6370 mg kg−1 Cu, 2210 mg kg−1 Pb and 5250 mg kg−1 Zn). The target organs of As, Cu and Pb accumulation were: root > leaf > stem in N. glauca, and root > stem ...
The dehesa is a traditional agrosilvopastoral ecosystem characterized by a savanna-like structure... more The dehesa is a traditional agrosilvopastoral ecosystem characterized by a savanna-like structure. It has been in decline since the middle of the last century, in particular in agricultural environments where it has been relegated to isolated forests. This paper presents a study into the reduction over the past 50 years. One of the main causes of this decline has been identified as xylophagous insects, specifically the wood borer Cerambyx welensii Kuster (Coleoptera: Cerambycidae). Based on estimations in both the population size, using Jolly Seber models, and the level of tree injury, using a single-index model, the study investigates the role the insect has played in the decline of the dehesa. Surface area loss was found to be greater than 50%, while canopy cover has diminished linearly over the period studied, with the risk of disappearance of the woodland increasing in the same magnitude as borer population density. The highest wood borer population densities observed correspond...
A 3-year male phenological field study was performed on the represented species of the genus Cupr... more A 3-year male phenological field study was performed on the represented species of the genus Cupressus in the city of Cordoba (Spain): Cupressus arizonica, C. macrocarpa and C. sempervirens. A new and complete description of the phenological stages of the male flower of Cupressus was obtained. Five phenolog-ical phases were described using internal and external bud/flower traits. In general, different pollination periods were recorded for the 3 years. C. arizonica flowered from 20 to 23 days before the others. C. macrocarpa and C. sempervirens flowered almost simultaneously, although the former appeared to flower slightly earlier. The total number of trees per square kilometre was estimated taking into account the total number of trees of each species in the city and surrounding area (5 km radius from the city centre). Data corresponding to total pollen production per tree were taken from a previous study in which the partial contribution of each species to atmospheric pollen was es...
On the presence of Narcissus scaberulus Henriq. (Amaryllidaceae) in western Andalusia (Spain). Na... more On the presence of Narcissus scaberulus Henriq. (Amaryllidaceae) in western Andalusia (Spain). Narcissus scaberulus Henriq. is recorded for the first time in western Andalusia, specifically from the province of Huelva.
The International Journal of Developmental Biology, 2001
Rosmarinus officinalis plants are self-compatible but automatic self-pollination is prevented by ... more Rosmarinus officinalis plants are self-compatible but automatic self-pollination is prevented by strong protandry. Flowers of R. officinalis set abundant seed when cross-pollinated by hand. Nevertheless, the seed set by self-pollination is clearly lower and similar in amount to those obtained in open-pollination. Insect-mediated geitonogamy is possible, and appears to be responsible for the lower seed set in open-pollination. Seed set by male-sterile plants indicates that gynodioecy could be considered as a strategy to increase reproductive output in R. officinalis. Two different steps can be distinguished in the halting of seed selfing: early abortion of the embryo/endosperm just after fertilisation, leading to small and empty seeds; and late abortion of the embryo, leading to empty but apparently normal seeds.
Habitat loss and fragmentation are considered some the main threats to biodiversity. Original for... more Habitat loss and fragmentation are considered some the main threats to biodiversity. Original forests have suffered an accentuated fragmentation and agricultural homogenization, leaving only some areas of natural vegetation, relegated to strongly anthropized disconnected patches (island forests, IFs) in a hostile matrix. These patches of original vegetation could be the key for the design and management of ecological corridors to promote species migration, an essential strategy for meeting the consequences of Global Change. This study proposes a comparative analysis of the fragmentation and connectivity of IFs of Quercus in two typically Mediterranean areas of predominantly agricultural use: the Guadalquivir valley (Spain) and the Apulia region (Italy). A retrospective comparison is also carried out in the Guadalquivir valley. The aim is to develop an objective new methodology to locate the patches of most interest using quantitative and qualitative data. Reference cartography of cu...
New floristic records of species for Doñana and Huelva (SW Spain) Palabras clave. Flora, Doñana, ... more New floristic records of species for Doñana and Huelva (SW Spain) Palabras clave. Flora, Doñana, Calystegia soldanella, Herniaria cinerea, Trigonella monspeliaca, Viola lactea, Wolffia arrhiza, especies amenazadas.Key words. Flora, Doñana, Calystegia soldanella, Herniaria cinerea, Trigonella monspeliaca, Viola lactea, Wolffia arrhiza, threatened species.
Potential pollen production, viability and germination were studied in the most important species... more Potential pollen production, viability and germination were studied in the most important species of Quercus in the mountains of Có rdoba to determine the contribution of each species to the total amount of airborne pollen. The results were compared over two consecutive years with different rainfall patterns. The viability of pollen grains was determined at anther opening, and during the pollination period, in order to determine potential pollination capacity. Results indicated that there were differences in the number of pollen grains produced by stamen in the four species. Equally, there were differences in the number of flowers among the species, being Q. suber the species with higher number of catkins groups and flowers per individual tree. Total pollen production per tree can be summarized in the following proportion: 1: 3: 3: 6 (Q. coccifera, Q. ilex ssp. ballota, Q. faginea and Q. suber). Potential pollen viability was estimated using the Fluorochromatic Reaction (FCR) and a germination assay. The results have shown that Quercus potential pollen viability is high and declines slowly with time. Q. coccifera was the species with the highest percentage of germination, with Q. suber being the lowest.
& Key message Composite logistic regression models simulating the potential effect of global clim... more & Key message Composite logistic regression models simulating the potential effect of global climate change on forests dynamics in the southern Iberian Peninsula identify Holm oak [Quercus ilex subsp. ballota (Desf.) Samp.] and Aleppo pine (Pinus halepensis Mill.) as the chief beneficiaries of the anticipated environmental shifts, whereas other oak species and conifers suffer a decline. & Context The ten most important tree species (five oaks and five conifers) in Southern Spain were selected for the study. The study area, corresponding to the region of Andalusia, is located in an interesting position between Central European and North African climates. The territory also exhibits the most extreme patterns of rainfall in the Iberian Peninsula. & Aims This study aims to model the potential distribution of the ten species in response to climate change, in several time periods, including the present and two future twenty-first century dates. & Methods The potential distributions within the different scenarios were simulated using logistic regression techniques based on a set of 19 climate variables from the WorldClim 1.4 project. The scenarios were drawn from the RCP 2.6 and 6.0 in the CCSM4 Global Circulation Model. The resolution of the output maps was 30 arc-seconds. & Results The simulation predicted increased distribution areas for Q. ilex and P. halepensis under the four future scenarios as compared to present. The eight remaining taxa suffered a severe retraction in potential distribution. & Conclusion Global climate change is likely to have a significant impact on forest dynamics in southern Spain. Only two species would benefit to the detriment of the others. Logistic Regression is identified as a robust method for carrying out management and conservation programmes.
Climate change models predict an increase in aridity in many parts of the world for the twenty-fi... more Climate change models predict an increase in aridity in many parts of the world for the twenty-first century, which is likely to be more intense in the Mediterranean basin than in other regions. This study addresses the potential distribution of three Mediterranean pine species (Pinus pinea L., P. halepensis Mill. and P. pinaster Aiton) in southern Spain in response to the forecast increased aridity. Pines constitute a useful source of various types of raw materials, which has led to their increasing introduction around the world. The study was based on ecological niche modelling using multinomial logistic regression, over an area spanning about 8.7 million ha in the south of Spain. In total, 11 explanatory variables were included, drawing on measurements made at high resolution (200 m). Four different periods were studied: the reference period (1961-2000), early twenty-first century (2011-2040), middle twenty-first century (2041-2070) and late twenty-first century (2071-2100). Future time slices were analysed in three different scenarios: B1, A1b and A2 in the CNCM3 general circulation model. The results predict a wider distribution for stone pine, which could expand its potential area in southern Spain. In contrast, Aleppo pine, and especially cluster pine, would reduce their present distribution, with cluster pine occupying higher altitude sites while low altitude populations diminished. The validation model enables accurate maps to be produced, representing powerful tools for afforestation/ reforestation programs in the future. Keywords Ecological niche modelling Á Global change Á Multinomial logistic regression Á Mediterranean pines Á Southern Spain Á Afforestation/reforestation programs Electronic supplementary material The online version of this article (
ABSTRACT Species which have suffered a contraction of their original distribution in a recent sta... more ABSTRACT Species which have suffered a contraction of their original distribution in a recent stage of the Earth’s history due to climate changes are termed climate relicts. In the Mediterranean basin, one of the most important hotspots of biodiversity in the world, many relict tree species remain in the mountain ranges. The Baetic range, situated in the southeast of the Iberian Peninsula, comprises three of these taxa (Pinus sylvestris L. var. nevadensis H. Christ, Pinus nigra Arnold subsp. salzmannii (Dunal) Franco and Abies pinsapo Boiss.), which grow in enclaves of suitable environmental conditions surrounded by an inhospitable regional climate. A high resolution predictive model for these species was carried out by making a grid of points with a resolution of 250 m, in which twelve explanatory variables were used: four topographical and eight climatic or bioclimatic. This grid also contains information about the presence/absence of the three species involved, which was used as the dependent variable. Then, a modeling process was carried out by means of binary logistic regression. According to the obtained model, climatic and bioclimatic independent variables (especially seasonal rainfall and mean temperatures) are more responsible for species distribution than topographic ones. The final potential distribution was found to be larger than the current one for all three species. This study is able to predict, with a high degree of accuracy, the potential distribution of the three species involved, and it is therefore proposed to implement reforestation programs at small-scale with high resolution (250 m). Other relict tree species from the Mediterranean basin or other places in the world could be modeled in the same way depending on measured variables.
• Biodiversity in this protected area was seriously affected. • The fire occurred under exception... more • Biodiversity in this protected area was seriously affected. • The fire occurred under exceptional synoptic and local meteorological conditions. • The fire reached El Arenosillo, and record-setting values of trace gases were measured. • The Doñana plume affected the western Mediterranean basin.
Taxus baccata is a relic declining species, especially at the southern margins of its natural dis... more Taxus baccata is a relic declining species, especially at the southern margins of its natural distribution, such as the Mediterranean and Irano-Turanian biogeographic regions. On the Island of Sardinia, it is still present in many mountain sites. This study identified 232 locations where yews grow. The species is indifferent to substrates, but prefers moist sites with northern aspects, and has elevation range is 695-1225 m a.s.l. To predict yew’s potential distribution in Sardinia, we collected data from the literature and field observations and applied the Maximum Entropy algorithm (MaxEnt). We used 202 field-based sites and 19 bioclimatic variables to model the potential distribution area under current climatic conditions. Annual precipitation, mean temperature of the warmest month and isothermality were the key drivers for the distribution of T. baccata in Sardinia. In terms of permutation importance, mean diurnal range and precipitation of the warmest quarter were the main environmental variables. The response curves showed that T. baccata prefers annual mean temperatures ranging from 8.65 to 12.55°C and annual mean precipitation from 770 to 1085 mm. Most potential suitable conditions were found in northern and central Sardinia. Using the Global Circulation Model, we also modelled future habitat suitability for T. baccata under two different scenarios, highlighting a substantial reduction of the habitat suitability for the species by the end of this century. This reduction is associated with climate change and poses an increasing concern about the future of the species and the priority habitat described in many parts of Sardinia.
This study examines 10 different taxa within the genus Abies identified in the circum-Mediterrane... more This study examines 10 different taxa within the genus Abies identified in the circum-Mediterranean area: A. alba, A. borisii-regis, A. cephalonica, A. cilicica, A. nebrodensis, A. nordmanniana subsp. equi-trojani, A. nordmanniana subsp. nordmanniana, A. numidica, A. pinsapo var. marocana and A. pinsapo var. pinsapo. We assess the potential distribution of these species in the Mediterranean Basin, most of Central-Northern Europe and Asia Minor through analysis of 8 bioclimatic variables. First, the potential distribution (suitability area) was calculated with Biomod2 package for R using 10 algorithms. Models were ensembled for the present period and then projected into two climate change scenarios (an intermediate and the most extreme) within two time slices (2041-2060 and 2081-2100) and two Global Circulation Models (GCMs). The analysis showed an increase in total suitable area under both forecasted scenarios. Abies spp. appeared to be resilient against climate change, showing a latitudinal and longitudinal migration trend in response to the loss of current habitats. A proposal of assisted migration (managed relocation) is suggested as an interesting alternative to guarantee the preservation of the most endangered species by promoting the establishment of new populations outside of their historical distribution area.
Predictions of an increase in mean temperatures and a widespread reduction in annual rainfall ove... more Predictions of an increase in mean temperatures and a widespread reduction in annual rainfall over the next few decades are consistent. Such drastic changes can have a serious, irreversible impact on the current distribution of trees and their ecosystems. Oaks are the most frequent trees in the better preserved areas of the Mediterranean basin; therefore, it is essential to understand potential shifts in their distribution for proper management and protection. The area studied in this work spans approximately 8.7 million hectares. The results obtained at 200 m resolution were subjected to logistic regression over four periods: current period (1961-2000), early twenty-first century (2011-2040), middle twenty-first century (2041-2070) and late twenty-first century (2071-2100). These periods were examined by using the CNCM3 model in an A1b scenario at 200 m resolution for the study area. Four of the five target species exhibited a narrower potential distribution in the twenty-first century. Cork oak and gall oak underwent a drastic potential reduction; on the other hand, Pyrenean oak and Algerian oak might find shelter at higher elevations. By exception, holm oak exhibited the opposite trend and was favoured by projected global warming. This projection is rather adverse for biodiversity and oak-dependent ecosystems. This study allowed an accurate prediction of the potential distribution of five different oak species and is therefore a promising, potentially effective tool for developing high-resolution reforestation programmes. Keywords Mediterranean oak trees Á Spatial modelling Á Global change Á Southern Spain Á Reforestation programmes Communicated by Joseph Paul Messina.
Page 1. Israel Journal of Plant Sciences Vol 49 2001 pp. 41^7 Catkin frost damage in Mediterranea... more Page 1. Israel Journal of Plant Sciences Vol 49 2001 pp. 41^7 Catkin frost damage in Mediterranean cork-oak {Quercus súber L.) Herminia García-Mozo,* Pablo J. Hidalgo, Carmen Galán, Maria Teresa Gómez-Casero, and ...
Sulfidic mine wastes have the potential to generate acid mine drainage (AMD) and release acid lea... more Sulfidic mine wastes have the potential to generate acid mine drainage (AMD) and release acid leachates containing high levels of iron, sulfate and potentially toxic elements (PTEs). Soils receiving AMD discharges are generally devoid of vegetation. Only a few metal-tolerant plant species can survive under such adverse soil conditions. This work investigates two plant species, Nicotiana glauca and Euphorbia segetalis, that have successfully colonized an AMD-impacted wetland area in south-western Spain. The uptake of PTEs from the soil by roots and their transfer and accumulation in the above-ground biomass were quantified. Results showed that these pioneer plants grew in patches of neutral soil within the wasteland despite the high concentrations of PTEs in the rhizosphere soil (up to: 613 mg kg−1 As, 18.7 mg kg−1 Cd, 6370 mg kg−1 Cu, 2210 mg kg−1 Pb and 5250 mg kg−1 Zn). The target organs of As, Cu and Pb accumulation were: root > leaf > stem in N. glauca, and root > stem ...
The dehesa is a traditional agrosilvopastoral ecosystem characterized by a savanna-like structure... more The dehesa is a traditional agrosilvopastoral ecosystem characterized by a savanna-like structure. It has been in decline since the middle of the last century, in particular in agricultural environments where it has been relegated to isolated forests. This paper presents a study into the reduction over the past 50 years. One of the main causes of this decline has been identified as xylophagous insects, specifically the wood borer Cerambyx welensii Kuster (Coleoptera: Cerambycidae). Based on estimations in both the population size, using Jolly Seber models, and the level of tree injury, using a single-index model, the study investigates the role the insect has played in the decline of the dehesa. Surface area loss was found to be greater than 50%, while canopy cover has diminished linearly over the period studied, with the risk of disappearance of the woodland increasing in the same magnitude as borer population density. The highest wood borer population densities observed correspond...
A 3-year male phenological field study was performed on the represented species of the genus Cupr... more A 3-year male phenological field study was performed on the represented species of the genus Cupressus in the city of Cordoba (Spain): Cupressus arizonica, C. macrocarpa and C. sempervirens. A new and complete description of the phenological stages of the male flower of Cupressus was obtained. Five phenolog-ical phases were described using internal and external bud/flower traits. In general, different pollination periods were recorded for the 3 years. C. arizonica flowered from 20 to 23 days before the others. C. macrocarpa and C. sempervirens flowered almost simultaneously, although the former appeared to flower slightly earlier. The total number of trees per square kilometre was estimated taking into account the total number of trees of each species in the city and surrounding area (5 km radius from the city centre). Data corresponding to total pollen production per tree were taken from a previous study in which the partial contribution of each species to atmospheric pollen was es...
On the presence of Narcissus scaberulus Henriq. (Amaryllidaceae) in western Andalusia (Spain). Na... more On the presence of Narcissus scaberulus Henriq. (Amaryllidaceae) in western Andalusia (Spain). Narcissus scaberulus Henriq. is recorded for the first time in western Andalusia, specifically from the province of Huelva.
The International Journal of Developmental Biology, 2001
Rosmarinus officinalis plants are self-compatible but automatic self-pollination is prevented by ... more Rosmarinus officinalis plants are self-compatible but automatic self-pollination is prevented by strong protandry. Flowers of R. officinalis set abundant seed when cross-pollinated by hand. Nevertheless, the seed set by self-pollination is clearly lower and similar in amount to those obtained in open-pollination. Insect-mediated geitonogamy is possible, and appears to be responsible for the lower seed set in open-pollination. Seed set by male-sterile plants indicates that gynodioecy could be considered as a strategy to increase reproductive output in R. officinalis. Two different steps can be distinguished in the halting of seed selfing: early abortion of the embryo/endosperm just after fertilisation, leading to small and empty seeds; and late abortion of the embryo, leading to empty but apparently normal seeds.
Habitat loss and fragmentation are considered some the main threats to biodiversity. Original for... more Habitat loss and fragmentation are considered some the main threats to biodiversity. Original forests have suffered an accentuated fragmentation and agricultural homogenization, leaving only some areas of natural vegetation, relegated to strongly anthropized disconnected patches (island forests, IFs) in a hostile matrix. These patches of original vegetation could be the key for the design and management of ecological corridors to promote species migration, an essential strategy for meeting the consequences of Global Change. This study proposes a comparative analysis of the fragmentation and connectivity of IFs of Quercus in two typically Mediterranean areas of predominantly agricultural use: the Guadalquivir valley (Spain) and the Apulia region (Italy). A retrospective comparison is also carried out in the Guadalquivir valley. The aim is to develop an objective new methodology to locate the patches of most interest using quantitative and qualitative data. Reference cartography of cu...
New floristic records of species for Doñana and Huelva (SW Spain) Palabras clave. Flora, Doñana, ... more New floristic records of species for Doñana and Huelva (SW Spain) Palabras clave. Flora, Doñana, Calystegia soldanella, Herniaria cinerea, Trigonella monspeliaca, Viola lactea, Wolffia arrhiza, especies amenazadas.Key words. Flora, Doñana, Calystegia soldanella, Herniaria cinerea, Trigonella monspeliaca, Viola lactea, Wolffia arrhiza, threatened species.
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