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Understanding of ecosystem structure and functioning requires detailed knowledge about plant–animal interactions, especially when keystone species are involved. The recent consideration of parrots as legitimate seed dispersers has widened the range of mechanisms influencing the life cycle of many plant species. We examined the interactions between the burrowing parrot Cyanoliseus patagonus and two dominant algarrobo trees (Prosopis alba and Prosopis nigra) in the Monte Desert, Argentina. We recorded the abundance and foraging behaviour of parrots; quantified the handling, consumption, wasting, and dispersal of ripe and unripe pods; and tested the viability of soft and hard ripe seeds wasted and transported by parrots. We found a high abundance of burrowing parrots. They predated on soft seeds from unripe pods while exclusively feeding upon pulp wrapping hard seeds from ripe pods. Frequent pod wasting beneath the plant or transport at a distance invariably implied the dispersal of multiple seeds in each event. Moreover, soft seeds retained viability after desiccation outside the mother plant, suggesting effective seed dispersal after partial pod predation due to a predator satiation effect. In about half of the foraging flocks, at least one parrot departed in flight with pods in its beak, with 10–34% of the flock components moving pods at distances averaging 238 m (P. alba) and 418 m (P. nigra). A snapshot sampling of faeces from livestock and wild mammals suggested a low frequency of seed dispersal by endozoochory and secondary dispersal by ants and dung beetles. The nomadic movements and long flights of burrowing parrots between breeding and foraging sites can lead to the dispersal of huge amounts of seeds across large areas that are sequentially exploited. Further research should evaluate the role of the burrowing parrot as a functionally unique species in the structure of the Monte Desert woods and the genetic structure of algarrobo species.
Guillermo Blanco; Pedro Romero-Vidal; Martina Carrete; Daniel Chamorro; Carolina Bravo; Fernando Hiraldo; José Tella. Burrowing Parrots Cyanoliseus patagonus as Long-Distance Seed Dispersers of Keystone Algarrobos, Genus Prosopis, in the Monte Desert. Diversity 2021, 13, 204 .
AMA StyleGuillermo Blanco, Pedro Romero-Vidal, Martina Carrete, Daniel Chamorro, Carolina Bravo, Fernando Hiraldo, José Tella. Burrowing Parrots Cyanoliseus patagonus as Long-Distance Seed Dispersers of Keystone Algarrobos, Genus Prosopis, in the Monte Desert. Diversity. 2021; 13 (5):204.
Chicago/Turabian StyleGuillermo Blanco; Pedro Romero-Vidal; Martina Carrete; Daniel Chamorro; Carolina Bravo; Fernando Hiraldo; José Tella. 2021. "Burrowing Parrots Cyanoliseus patagonus as Long-Distance Seed Dispersers of Keystone Algarrobos, Genus Prosopis, in the Monte Desert." Diversity 13, no. 5: 204.
Mediterranean shrublands are water-limited and fire-prone ecosystems. Post-fire seed regeneration occurs under a rainfall regime that is highly variable, with frequent drought periods. It has been shown that smoke can alter germination performance in numerous species, but little is known about its role during germination under water stress. Here, we studied the germination response to water stress and smoke of nine abundant Mediterranean shrubs. Seeds of six species with hard coats (three Cistaceae and three Fabaceae) and three with soft coats (Lamiaceae), exposed or not to smoke, were set to germinate under four levels of water availability (0; − 0.15; − 0.30; − 0.45 MPa). Seeds of hard-coat species were previously mechanically scarified. Onset of germination, final germination and viability were recorded. Water stress reduced final germination in five of the six hard-coat species and in one soft-coat species, delayed the onset of germination in all species and decreased viability in several hard-coat species. Smoke increased final germination (10%) in one soft-coat species, not affecting the rest. Additionally, smoke reduced the onset of germination in one hard- and one soft-coat species. However, there was no interaction between smoke and water stress. Hydrotime modeling of the germination responses confirmed the above findings. In conclusion, the species studied differed in germination sensitivity to water stress, with hard-coat species being more sensitive than soft-coat species. Exposing the seeds to smoke generally did not change this sensitivity.
Daniel Chamorro; José M. Moreno. Effects of water stress and smoke on germination of Mediterranean shrubs with hard or soft coat seeds. Plant Ecology 2019, 220, 511 -521.
AMA StyleDaniel Chamorro, José M. Moreno. Effects of water stress and smoke on germination of Mediterranean shrubs with hard or soft coat seeds. Plant Ecology. 2019; 220 (4-5):511-521.
Chicago/Turabian StyleDaniel Chamorro; José M. Moreno. 2019. "Effects of water stress and smoke on germination of Mediterranean shrubs with hard or soft coat seeds." Plant Ecology 220, no. 4-5: 511-521.
In seasonal climates, germination timing is mainly controlled by temperature, especially in species with physiological seed dormancy. The germination response to temperature may, however, vary among populations across the distribution range of species. Understanding how populations along climate gradients vary in their sensitivity to temperature is important for determining their vulnerability to climate variability and change. Here, we investigated the germination response of two Erica species with physiological seed dormancy (E. australis and E. umbellata) to changes in temperature throughout the seasons (simulated autumn through to spring) and to the local climate in six localities across a latitudinal gradient in western Iberia. Effects were studied with and without exposing the seeds to a heat shock. The local climate of seed provenance emerged as a key factor in modifying the germination sensitivity to germination temperature and their variation through the seasons. Although each species showed idiosyncratic germination responses to temperature treatments and across the gradient, germination of both species was sensitive to warmer temperatures and to a heat shock. Both showed similar seasonal germination patterns: as we moved from south to north, populations tended to have a larger germination peak in spring, which was greater at colder temperatures. We conclude that rising temperatures associated with climate change will affect these species, particularly at their northern ranges, where many seeds will remain dormant during warmer winters. Arguably, models aiming at assessing climate change impacts in these species need to include such variability across latitude.
Daniel Chamorro; Belén Luna; José M. Moreno. Local climate controls among-population variation in germination patterns in two Erica species across western Iberia. Seed Science Research 2018, 28, 112 -122.
AMA StyleDaniel Chamorro, Belén Luna, José M. Moreno. Local climate controls among-population variation in germination patterns in two Erica species across western Iberia. Seed Science Research. 2018; 28 (2):112-122.
Chicago/Turabian StyleDaniel Chamorro; Belén Luna; José M. Moreno. 2018. "Local climate controls among-population variation in germination patterns in two Erica species across western Iberia." Seed Science Research 28, no. 2: 112-122.
PREMISE OF THE STUDY: Species differ in their temperature germination niche. Populations of a species may similarly differ across the distribution range of the species. Anticipating the impacts of climate variability and change requires understanding the differential sensitivity to germination temperature among and within species. Here we studied the germination responses of four hard-seeded Cistaceae seeders to a range of current and future temperatures. METHODS: Seeds were collected at sites across the Iberian Peninsula and exposed or not exposed to a heat shock to break dormancy, then set to germinate under four temperature regimes. Temperatures were varied daily and seasonally, simulating the temperature range across the gradient, plus an increased temperature simulating future climate. Time to germination onset and cumulative germination at the end of each season were analyzed for the effects of temperature treatments, seasons, and local climate (temperature of the germination period, Tgp) at each site. KEY RESULTS: Tgp was a significant covariate of germination in all species but Cistus populifolius. Temperature treatments significantly affected Cistus ladanifer, C. salviifolius, and Halimium ocymoides. Germination occurred in simulated autumn conditions, with little germination occurring at later seasons, except in unheated seeds of H. ocymoides. Exposure to a heat shock changed the sensitivity to temperature treatments and the relationships with Tgp. CONCLUSIONS: Germination responses to temperature differ not only among species but also within species across their latitudinal range. The responses were idiosyncratic and related to the local climate of the population. This germination variability complicates generalizing the impacts of climate variability and climate change.
Daniel Chamorro; Belén Luna; José M. Moreno. Germination responses to current and future temperatures of four seeder shrubs across a latitudinal gradient in western Iberia. American Journal of Botany 2017, 104, 83 -91.
AMA StyleDaniel Chamorro, Belén Luna, José M. Moreno. Germination responses to current and future temperatures of four seeder shrubs across a latitudinal gradient in western Iberia. American Journal of Botany. 2017; 104 (1):83-91.
Chicago/Turabian StyleDaniel Chamorro; Belén Luna; José M. Moreno. 2017. "Germination responses to current and future temperatures of four seeder shrubs across a latitudinal gradient in western Iberia." American Journal of Botany 104, no. 1: 83-91.
Water availability regulates timing of germination, especially in those environments where it is a limiting factor. However, the water requirements for germination of most wild Mediterranean species are unknown. In this work we analysed the germination response to water stress of eight Cistaceae species with hard-coated seeds, which are typical for the Mediterranean shrublands. Seeds were exposed to a heat shock in order to overcome physical dormancy and then incubated under five water potentials (0, −0.2, −0.4, −0.6 and −0.8 MPa). Ungerminated seeds following these treatments were transferred to water in order to evaluate the recovery of germination. Additionally, at the end of the experiment, viability of still ungerminated seeds was examined. We analysed final germination percentage, time to reach 50% of the final germination (t50), recovery of germination and seed viability in relation to water stress treatments. Furthermore, hydrotime analysis was performed; sensitivity to water stress, as characterized by Ψb(50), was checked in relation to seed size of species. Overall, water stress delayed and decreased germination but species showed different germination sensitivities, which were not related to seed size. Recovery of germination was high after disappearance of water stress but seed viability decreased in some species. Consequently, post-fire germination of Cistaceae must be strongly regulated by water availability and their seeds can recover germination capacity when sufficient water is available after long periods of incomplete hydration. However, some seeds die during the wait.
Belén Luna; Daniel Chamorro. Germination sensitivity to water stress of eight Cistaceae species from the Western Mediterranean. Seed Science Research 2016, 26, 101 -110.
AMA StyleBelén Luna, Daniel Chamorro. Germination sensitivity to water stress of eight Cistaceae species from the Western Mediterranean. Seed Science Research. 2016; 26 (2):101-110.
Chicago/Turabian StyleBelén Luna; Daniel Chamorro. 2016. "Germination sensitivity to water stress of eight Cistaceae species from the Western Mediterranean." Seed Science Research 26, no. 2: 101-110.
Mediterranean shrublands are generally water-limited and fire-driven ecosystems. Seed-based post-fire regeneration may be affected by varying rainfall patterns, depending on species’ sensitivity to germinate under water stress. In our study, we considered the germination response to water stress in four species from multiple sites across the Mediterranean Basin. Seeds of species with hard-coated (Cistus monspeliensis, C. salviifolius [Cistaceae], Calicotome villosa [Fabaceae]) or soft-coated (Erica arborea [Ericaceae]) seeds, which were exposed or otherwise to a heat shock and smoke (fire cues), were made to germinate under water stress. Final germination percentage, germination speed and viability of seeds were recorded. Germination was modelled using hydrotime analysis and correlated to the water-balance characteristics of seed provenance. Water stress was found to decrease final germination in the three hard-seeded species, as well as reduce germination speed. Moreover, an interaction between fire cues and water stress was found, whereby fire cues increased the sensitivity to water stress. Seed viability after germination under water stress also declined in two hard-seeded species. Conversely, E. arborea showed little sensitivity to water stress, independent of fire cues. Germination responses varied amongst populations of all species, and hydrotime parameters were not correlated to site water-balance, except in E. arborea, when not exposed to fire cues. In conclusion, the species studied differed in germination sensitivity to water stress; furthermore, fire cues increased this sensitivity in the three hard-seeded species, but not in E. arborea. Moreover, populations within species consistently differed amongst themselves, but these differences could only be related to the provenance locality in E. arborea in seeds not exposed to fire cues. This article is protected by copyright. All rights reserved.
Daniel Chamorro; Belén Luna; Jean‐Marc Ourcival; Ali Kavgaci; Costantino Sirca; Florent Mouillot; Margarita Arianoutsou; José M. Moreno. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin. Plant Biology 2016, 19, 23 -31.
AMA StyleDaniel Chamorro, Belén Luna, Jean‐Marc Ourcival, Ali Kavgaci, Costantino Sirca, Florent Mouillot, Margarita Arianoutsou, José M. Moreno. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin. Plant Biology. 2016; 19 (1):23-31.
Chicago/Turabian StyleDaniel Chamorro; Belén Luna; Jean‐Marc Ourcival; Ali Kavgaci; Costantino Sirca; Florent Mouillot; Margarita Arianoutsou; José M. Moreno. 2016. "Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin." Plant Biology 19, no. 1: 23-31.
Reproductive output and seed traits can be altered by water availability during seed formation and maturation, which could affect the population recovery after fire of seeders (i.e., species regenerating from seeds). This is important for species in fire-prone, dry areas that are projected to encounter reduced total precipitation and longer annual drought with climate change. Here we determine the sensitivity of several reproductive processes to drought in Cistus ladanifer, a plant widely distributed in the shrublands of the western part of the Mediterranean Basin. Three levels of annual drought were simulated in a shrubland by means of a rainout shelter and an irrigation system in 6 × 6 m plots. Fruits and seeds from drought-exposed mother plants were collected, and reproductive output, seed size and anatomy studied. Seeds non-exposed/exposed to fire cues (heat plus smoke) were germinated at five levels of water stress (Ψs = 0.0 to −0.50 MPa). Hydrotime modeling was applied to germination under water stress. Plant growth was sensitive to drought, but reproductive output, seed size, dormancy and viability were not. Drought significantly affected seed anatomy, increasing the palisade layer at the micropyle. Drought in the maternal plants, in interaction with seed exposure to fire cues, significantly reduced final germination. Water stress during germination decreased final germination, independent of maternal plant drought, and interacted with fire cues to decrease germination when exposed. Hydrotime modeling confirmed that fire cues made seeds highly sensitive to water stress (Ψb (50) = −0.25 MPa). Post-germination viability was reduced in seeds from drought-treated maternal plants that were exposed to fire cues and germinated under water stress. Reproductive output showed low plasticity in response to drought. However, the effects of drought in the mother plant affected seed anatomy and germination in interaction with fire cues. The conclusion is that exposing C. ladanifer maternal plants to drought arguably increases seed sensitivity to water limitations during germination after fire.
D. Chamorro; A. Parra; J.M. Moreno. Reproductive output, seed anatomy and germination under water stress in the seeder Cistus ladanifer subjected to experimental drought. Environmental and Experimental Botany 2016, 123, 59 -67.
AMA StyleD. Chamorro, A. Parra, J.M. Moreno. Reproductive output, seed anatomy and germination under water stress in the seeder Cistus ladanifer subjected to experimental drought. Environmental and Experimental Botany. 2016; 123 ():59-67.
Chicago/Turabian StyleD. Chamorro; A. Parra; J.M. Moreno. 2016. "Reproductive output, seed anatomy and germination under water stress in the seeder Cistus ladanifer subjected to experimental drought." Environmental and Experimental Botany 123, no. : 59-67.
Despite the fact that parrots (Psitacifformes) are generalist apex frugivores, they have largely been considered plant antagonists and thus neglected as seed dispersers of their food plants. Internal dispersal was investigated by searching for seeds in faeces opportunistically collected at communal roosts, foraging sites and nests of eleven parrot species in different habitats and biomes in the Neotropics. Multiple intact seeds of seven plant species of five families were found in a variable proportion of faeces from four parrot species. The mean number of seeds of each plant species per dropping ranged between one and about sixty, with a maximum of almost five hundred seeds from the cactiPilosocereus pachycladusin a single dropping of Lear’s Macaw (Anodorhynchus leari). All seeds retrieved were small (
Guillermo Blanco; Carolina Bravo; Erica C. Pacifico; Daniel Chamorro; Karina L. Speziale; Sergio Lambertucci; Fernando Hiraldo; José L. Tella. Internal seed dispersal by parrots: an overview of a neglected mutualism. PeerJ 2016, 4, e1688 .
AMA StyleGuillermo Blanco, Carolina Bravo, Erica C. Pacifico, Daniel Chamorro, Karina L. Speziale, Sergio Lambertucci, Fernando Hiraldo, José L. Tella. Internal seed dispersal by parrots: an overview of a neglected mutualism. PeerJ. 2016; 4 ():e1688.
Chicago/Turabian StyleGuillermo Blanco; Carolina Bravo; Erica C. Pacifico; Daniel Chamorro; Karina L. Speziale; Sergio Lambertucci; Fernando Hiraldo; José L. Tella. 2016. "Internal seed dispersal by parrots: an overview of a neglected mutualism." PeerJ 4, no. : e1688.
In dry-summer seasonal climates, the beginning of the rainy season can prompt germination under different temperatures, depending on altitude. Understanding germination responses to temperature with altitude is important in fire-prone environments for species regenerating after fire from seeds (seeders), particularly under changing climate. Here we investigated the role of temperature in four Mediterranean seeder shrubs from Central Spain. Seeds from 17 sites (285–1,253 m altitude), of two hard-seeded nanophanerophytes (Cistus ladanifer and C. salviifolius) and two soft-seeded chamaephytes (Lavandula pedunculata and Thymus mastichina) were investigated. Intact and heat shock treated seeds were set to germinate under four temperature regimes, including a treatment simulating future warming. GLM with binomial or gamma functions were used to test treatment effects using altitude as a covariate. Altitude was a significant covariate only in L. pedunculata. Temperature did not affect final germination in either Cistus, but it significantly affected T. mastichina, and interacted with altitude in L. pedunculata, whereby the higher the altitude the less it germinated with decreasing temperature. Germination speed (T50) was lower at colder temperatures in all but C. salviifolius that was insensitive to our treatments. Heat shock significantly increased final germination in both Cistus and T. mastichina, but did not interact with temperature or altitude. We conclude that germination response to temperature, including varying sensitivity with altitude, differed among these species; thus, changes in the timing of the onset of the rainy season will diversely affect populations at various altitudes. We discuss our results in a context of changing climate and fire.
Daniel Chamorro; Belén Luna; José M. Moreno. Germination response to various temperature regimes of four Mediterranean seeder shrubs across a range of altitudes. Vegetatio Acta Geobotanica 2013, 214, 1431 -1441.
AMA StyleDaniel Chamorro, Belén Luna, José M. Moreno. Germination response to various temperature regimes of four Mediterranean seeder shrubs across a range of altitudes. Vegetatio Acta Geobotanica. 2013; 214 (12):1431-1441.
Chicago/Turabian StyleDaniel Chamorro; Belén Luna; José M. Moreno. 2013. "Germination response to various temperature regimes of four Mediterranean seeder shrubs across a range of altitudes." Vegetatio Acta Geobotanica 214, no. 12: 1431-1441.