Person:
Acosta Gallo, Belén

First Name

Belén

Last Name

Acosta Gallo

URI

https://hdl.handle.net/20.500.14352/74367

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Biológicas

Department

Biodiversidad, Ecología y Evolución

Area

Ecología

Identifiers

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Search Results

Now showing 1 - 9 of 9

The invasiveness of Hypochaeris glabra (Asteraceae): Responses in morphological and reproductive traits for exotic populations
(PLoS ONE, 2018) Martín Forés, Irene; Acosta Gallo, Belén; Castro Parga, Isabel; Miguel Garcinuño, José Manuel de; Pozo Lira, Alejandro del; Casado González, Miguel Ángel
Scientists have been interested in many topics driven by biological invasions, such as shifts in the area of distribution of plant species and rapid evolution. Invasiveness of exotic plant species depends on variations on morphological and reproductive traits potentially associated with reproductive fitness and dispersal ability, which are expected to undergo changes during the invasion process. Numerous Asteraceae are invasive and display dimorphic fruits, resulting in a bet-hedging dispersal strategy ±wind-dispersed fruits versus animal-dispersed fruits±. We explored phenotypic differentiation in seed morphology and reproductive traits of exotic (Chilean) and native (Spanish) populations of Hypochaeris glabra. We collected flower heads from five Spanish and five Chilean populations along rainfall gradients in both countries. We planted seeds from the ten populations in a common garden trial within the exotic range to explore their performance depending on the country of origin (native or exotic) and the environmental conditions at population origin (precipitation and nutrient availability). We scored plant biomass, reproductive traits and fruit dimorphism patterns. We observed a combination of bet-hedging strategy together with phenotypic differentiation.Native populations relied more on bet-hedging while exotic populations always displayed greater proportion of wind-dispersed fruits than native ones. This pattern may reflect a strategy that might entail a more efficient long distance dispersal of H. glabra seeds in the exotic range, which in turn can enhance the invasiveness of this species.
From Spain to Chile: environmental filters and success of herbaceous species in Mediterranean-climate regions
(Biological Invasions, 2015) Martín Forés, Irene; Sánchez Jardón, Laura; Acosta Gallo, Belén; Pozo Lira, Alejandro del; Castro Parga, Isabel; Miguel Garcinuño, José Manuel de; Ovalle, Carlos; Casado González, Miguel Ángel
In central Chile, many exotic species associated with cereal culture and livestock activities were introduced during Spanish colonization. Nowadays, Chilean semi-natural grasslands are a mixture of native species and exotics that mainly originated in the Mediterranean Basin. The establishment and persistence of exotics (i.e. naturalization) can be due to abiotic (climate and soil properties) and biotic (interaction between plants) factors. We assess the importance of these environmental factors as filters that have promoted/ limited the successful naturalization of Spanish species in Chile. Fifteen sites distributed throughout a wide range of Mediterranean climatic conditions, with similar geomorphology and land-use, were selected in both Chile and Spain. At each site we recorded a broad set of soil and climate variables as well as plant species richness during two consecutive years. In Chile, species were classified as natives or exotics whereas in Spain species were classified as colonizers (species that have been naturalized in Chile) or exclusives (only present in Spain).Species richness was higher in Spain (229 species) than in Chile (152), the latter with a high proportion (almost 50 %) of exotics. Different environmental factors affected species richness in each Mediterranean region. In Spain, species classified as colonizers were weakly related to a combination of soil and climate properties, while in Chile the number of exotic species was highly related with climate conditions (especially water availability). Lack of association between native and exotics pecies richness indicated that biotic filters (i.e. species competition) are less important than abiotic ones in transcontinental naturalization in Chile.
Variability of herbaceous productivity along Nothofagus pumilio forest-open grassland boundaries in northern Chilean Patagonia
(Agroforestry Systems, 2014) Sánchez Jardón, Laura; Acosta Gallo, Belén; Pozo Lira, Alejandro del; Casado González, Miguel A.; Ovalle Molina, Carlos; Miguel Garcinuño, José Manuel de
In order to develop a general model of aboveground net primary production (ANPP) of herbaceous communities in grazing systems that combine forested and open grasslands in temperate areas, biomass production and a set of biotic and abiotic variables were measured at four adjacent forest and grassland sites in Chile’s northern Patagonia for two consecutive growing seasons. At each site, one transect of 80 m long (40 m in open grassland and 40 m in forest) × 10 m wide was established. ANPP was significantly higher in open grasslands but no gradual change in biomass production was observed from inside the forest towards the open grassland. In open grasslands ANPP was spatially uniform but highly variable between years of contrasting weather conditions, whereas in forests it was more spatially heterogeneous and less variable over time. ANPP was highly correlated with cattle consumption. Structural equation models developed for the whole system confirm that ANPP was driven mainly by photosynthetically active radiation (PAR) and available nitrogen. However, we found important differences between forests and the adjacent open grasslands. In forests ANPP was enhanced by positive feedbacks between the amount of transmitted PAR through the canopy and soil nutrient input via cattle dung deposition. In open grasslands nitrogen availability appeared to be the main limiting factor but also influenced by weather conditions (dryer or wetter years). The coexistence of forests and grasslands patches, with different susceptibility of ANPP to meteorological and soil nutrient availability, highlights the importance of implementing an integrated silvopastoral system with lenga (Nothofagus pumilio [Poepp. & Endl.] Krasser) in northern Patagonia.
Bosque y matorral esclerófilo mediterráneo
(Ambienta, 2012) Díaz Pineda, Francisco; Acosta Gallo, Belén
Understanding Mediterranean Pasture Dynamics: General Tree Cover vs. Specific Effects of Individual Trees
(Rangeland Ecology and Management, 2013) Miguel Garcinuño, José Manuel de; Acosta Gallo, Belén; Gómez-Sal, Antonio
The study investigated the effect of general and homogeneous tree cover on grassland composition on an extensive Mediterranean rangeland with sparse oak trees in central Spain. We analyzed this effect together with other significant factors identified in this type of rangeland: topography and plowing. Data were collected in the 1984 growing season and they form part of a historical database on the characteristics of vegetation and livestock behavior; these data refer to grasslands below and away from the tree crowns of 91 individual trees, located in different topographical positions and in areas that were last plowed at different times. We used multivariate analyses to identify the main compositional trends of variation in pasture communities. The results indicate that the herbaceous community below tree crowns was more similar to that of the lowland areas than to the nearby areas away from the tree. This result supports the idea of tree cover in semiarid rangelands as a factor attenuating the effects on pastures of environmental conditions typical of high and intermediate topographical positions—generally presenting low soil moisture and fertility. Coupled with this, we also found effects of some individual trees related with the way livestock uses them as shelter and resting places. Our results indicate that the role played by dispersed trees in the management of this type of rangeland should be analyzed at two complementary spatial scales: the overall effect of tree cover as a factor acting at landscape scale and the specific effect of some individual trees acting at a more detailed scale.
Asymmetric fows and drivers of herbaceous plant invasion success among Mediterranean-climate regions
(Scientific Reports, 2018) Casado Hernández, Miguel Ángel; Martín Forés, Irene; Castro Parga, Isabel; Miguel Garcinuño, José Manuel; Acosta Gallo, Belén
Understanding the mechanisms that support the arrival, establishment and spread of species over an introduced range is crucial in invasion ecology. We analysed the unintentionally introduced herbaceous species that are naturalised in the fve Mediterranean-climate regions. There is an asymmetry in the species fows among regions, being the Iberian Peninsula the main donor to the other regions. At interregional scale, the species’ capacity to spread among regions is related to the ecological versatility of the species in the donor area (Iberian Peninsula). At intraregional scale, the species’ capacity to successfully occupy a complete region frst depends on the time elapsed from its introduction and afterwards on the degree of occurrence in the region of origin, which is commonly related to its chance of coming into contact with humans. Information on exotic species in their origin region provides insights into invasion process and decision-making to reduce the risks of future invasions.
Interactive effects of source and recipient habitats on plant invasions: distribution of exotic species in Chile
(Diversity and Distributions, 2015) Casado Hernández, Miguel Ángel; Acosta Gallo, Belén; Sánchez Jardón, Laura; Martín Forés, Irene; Castro Parga, Isabel; Ovalle, Carlos; Pozo Lira, Alejandro; Miguel Garcinuño, José Manuel de
Aim: Most studies on invasibility consider the characteristics of the habitats colonized. However, the success of the establishment of exotic species can be conditioned by the characteristics of the donor communities. In this study, we analyse the extent to which the distribution of exotic herbaceous species in Chile is conditioned either by the climatic characteristics of the recipient area or by the environmental features of the source areas on the Iberian Peninsula. Location: Chile and the Iberian Peninsula (Portugal and Spain). Methods: for Chile, we characterized the exotic species according to their current Chilean distribution and their region of origin. For the Iberian Peninsula, we compiled the ﬂoristic composition of 11,702 releves. We classiﬁed each releve according to key habitat characteristics (bioclimate, soil nutrient status and type of community associated with human activities) and calculated the percentage of species in common with Chile in different climatic regions therein. Results: Over half of Chile’s exotic species exhibited a geographic distribution related to the climate of the recipient area. The main donor communities were those associated with ruderal and arable land habitats, although their importance depended upon the climate in the recipient area. Correspondence was observed between the climatic characteristics of the communities in the source area and those of the recipient areas. Main conclusions: the results highlight the inﬂuence of the characteristics of habitats in the source area on the successful establishment of exotic species in Chile. The relationships between source and recipient area are scale dependent, climate constituting the main driver at broad scale. Within each climatic region, the communities associated with habitats presenting greater anthropic inﬂuence act as the main donors. Both features indicate the existence of ﬁlters that select species pre-adapted to the climatic and habitat conditions in the recipient area.
Ecotypic differentiation and phenotypic plasticity combine to enhance the invasiveness of the most widespread daisy in Chile, Leontodon saxatilis
(Scientific Reports, 2017) Martín Forés, Irene; Avilés, Marta; Acosta Gallo, Belén; Breed, Martin F.; Pozo Lira, Alejandro del; Miguel Garcinuño, José Manuel de; Sánchez Jardón, Laura; Castro Parga, Isabel; Ovalle, Carlos; Casado González, Miguel Ángel
Dispersal and reproductive traits of successful plant invaders are expected to undergo strong selection during biological invasions. Numerous Asteraceae are invasive and display dimorphic fruits within a single flower head, resulting in differential dispersal pathways - wind-dispersed fruits vs. nondispersing fruits. We explored ecotypic differentiation and phenotypic plasticity of seed output and fruit dimorphisms in exotic Chilean and native Spanish populations of Leontodon saxatilis subsp. rothii. We collected flower heads from populations in Spain and Chile along a rainfall gradient. Seeds from all populations were planted in reciprocal transplant trials in Spain and Chile to explore their performance in the native and invasive range. We scored plant biomass, reproductive investment and fruit dimorphism. We observed strong plasticity, where plants grown in the invasive range had much greater biomass, flower head size and seed output, with a higher proportion of wind-dispersed fruits, than those grown in the native range. We also observed a significant ecotype effect, where the exotic populations displayed higher proportions of wind-dispersed fruits than native populations. Together, these patterns reflect a combination of phenotypic plasticity and ecotypic differentiation, indicating that Leontodon saxatilis has probably increased propagule pressure and dispersal distances in its invasive range to enhance its invasiveness.
Allometric patterns of below-ground biomass in Mediterranean grasslands
(Plant Biosystems, 2011) Acosta Gallo, Belén; Casado González, Miguel Ángel; Montalvo, J.; Díaz Pineda, Francisco
Below-ground biomass might play an important role in the persistence of grasslands. The summertime water stress of Mediterranean grasslands very much accounts for annual plants in their communities. These plants die off in summer, and the soil seed bank ensures the grasslands' recovery every autumn. Temperature decreases with altitude, together with the proportion of annual and perennial herbs. This paper explores the vertical profile of this biomass in grasslands on the Iberian Península along an altitudinal gradient and two geomorphological positions in each site. Both factors were considered to determine the development of below-ground biomass. We also took Ínto consideration the experimental exclusion of livestock, considering that the presence or absence of herbivores may infiuence the aerial and underground structure of the grasslands. Using an allometric approach, we examined the relative distribution ofbelow-ground biomass with depth and its temporal variation ("construction"). We found that there is a general allometric pattern in the vertical profile ofvariation of below-ground biomass in which density is inversely proportional to the depth of the stratum raised ro· the power of 1.8 (at high elevations) and 2.5 (low elevations). The construction process of these grasslands exhibits slight variations within a common pattern. Growth of the plant canopy can be temporally limited by the action of herbivores, a more complex underground structure thereby developing, with more strata and a more even biomass distribution. An adaptive reaction to the notable Mediterranean seasonal change appears to occur but, surprisingly, may depend upon altitude rather than upon the infiuence of herbivory.