Guillermo Funes

New handbook for standardised measurement of plant functional traits worldwide

Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait syndromes, has proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure ecologically meaningful plant traits. This line of research has been among the most fruitful avenues for understanding ecological and evolutionary patterns and processes. It also has the potential both to build a predictive set of local, regional and global relationships between plants and environment and to quantify a wide range of natural and human-driven processes, including changes in biodiversity, the impacts of species invasions, alterations in biogeochemical processes and vegetation–atmosphere interactions. The importance of these topics dictates the urgent need for more and better data, and increases the value of standardised protocols for quantifying trait variation of different species, in particular for traits with power to predict plant- and ecosystem-level processes, and for traits that can be measured relatively easily. Updated and expanded from the widely used previous version, this handbook retains the focus on clearly presented, widely applicable, step-by-step recipes, with a minimum of text on theory, and not only includes updated methods for the traits previously covered, but also introduces many new protocols for further traits. This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties. We hope this new handbook becomes a standard companion in local and global efforts to learn about the responses and impacts of different plant species with respect to environmental changes in the present, past and future.

Floristic composition, biomass, and aboveground net plant production in grazed and protected sites in a mountain grassland of central Argentina

Abstract Changes in plant community composition, diversity, aboveground biomass, and aboveground net primary production (ANPP) of different plant growth-forms were assessed in sites protected from livestock grazing for 2, 4, and 15 years, and in a heavily-grazed site. Species richness was maximum at the grazed site and decreased significantly after 4 years of protection. Diversity decreased significantly only after 15 years of protection. No alien or weedy species were found at grazed or protected sites. Grazing exclusion produced a shift from grazing-tolerant or grazing-avoiding species with a graminoid or prostrate growth-form to taller species with a tall tussock growth-form. Grazing produced a 33% decrease in standing biomass but little change in ANPP when compared to the site protected from grazing for 2 years, but important changes in both biomass and ANPP respect to the sites protected for 4 and 15 years. Consumption was near 35% of ANPP.

Seed size and shape are good predictors of seed persistence in soil in temperate mountain grasslands of Argentina

We tested whether seed mass and shape are good predictors of seed persistence in the soil of subhumid temperate montane grasslands of central Argentina. We plotted seed mass against variance of seed dimensions of 71 herbaceous species and obtained information on their persistence in the soil from a previous experiment on germinable seed banks. We identified a certain seed mass/shape combination beyond which no seed was persistent in the soil, with the exception of the annual Tagetes minuta . Our results confirmed the patterns previously reported for British species: small and compact seeds tend to persist in the soil for a longer time than big and elongated or flattened seeds. We suggest that the value of seed mass and shape as predictors of persistence in the soil can be extended beyond the British flora to herbaceous floras from other humid temperate regions.

Seed bank dynamics in tall-tussock grasslands along an altitudinal gradient

Abstract We studied the germinable soil seed bank of tall-tussock grasslands along an altitudinal gradient in the mountains of central Argentina. We selected 10 sampling plots at three altitudinal levels (1200 m, 1600 m and 2200 m). We assessed the composition of the established vegetation and took ten compound soil samples (0 - 5 cm depth) at each plot in autumn and spring. The soil samples were sieved, chilled, and incubated in a glasshouse to assess the composition of the seed bank. The similarity between the composition of the seed bank flora and that of the established vegetation was low throughout the gradient. Most species did not change their seed bank strategy along the gradient. Seed bank richness and density increased with altitude. Most species had a persistent seed bank at all altitudinal levels, and the proportion of such species increased with altitude. These results suggest that a cold climate directly and/or indirectly favours the formation of seed banks and seed persistence in the soil. Nomenclature: Zuloaga et al. (1994); Zuloaga & Morrone (1996, 1999).

Germination Characteristics of Four Argentinean Endemic Gymnocalycium (Cactaceae) Species With Different Flowering Phenologies

Abstract We analyzed germination percentages and germination rates at four temperature treatments (5/15, 10/20, 15/25 and 20/35 °C) and in light or darkness in four endemic species of the genus Gymnocalycium with different flowering phenologies from the Córdoba Mountains (Argentina). Gymnocalycium bruchii flowered and dispersed its seeds very early in the season in comparison to the other three species. No seeds germinated in darkness or at the coldest temperature regime. For all species except G. bruchii, germination was higher at the two warmest treatments. Gymnocalycium bruchii germination was maximum at the second warmest temperature (15/25 °C) and did not germinate at all at the highest temperature treatment (20/35 °C). Germination varied strongly among species, from about 80% in G. quehliaum to 20% in G. monvillei. Germination rate (t50) varied more strongly among temperature treatments (from 15 to 7 days in the coldest and warmest treatments respectively) than among species. The lack of germination of G. bruchii at 20–35 °C could be related to its early flowering phenology.

Efectos del pastoreo sobre el banco de semillas germinable y la vegetación establecida en pastizales de montaña del centro de Argentina

Se estudio el efecto del pastoreo sobre el banco de semillas y la vegetacion establecida en pastizales naturales de montana, en Pampa de Achala, Cordoba, Argentina. Se analizo el banco de semillas germinable a dos profundidades (0-5 y 5-10 cm), en cinco replicas de sitios pastoreados a carga moderada-intensa y otros cinco de sitios excluidos al pastoreo por 10 anos. Se registro la frecuencia de las especies presentes en la vegetacion establecida y la abundancia de las especies en el banco de semillas. El pastoreo no produjo cambios significativos en el numero de especies de la comunidad establecida, pero si produjo un incremento en la diversidad de especies debido a una disminucion de la frecuencia de algunos pastos perennes como Deyeuxia hieronymi y Festuca tucumanica. Se registraron solo tres especies exoticas en los pastizales estudiados. El pastoreo no produjo cambios significativos en la riqueza ni en la diversidad de especies del banco de semillas. La densidad total de semillas en el banco tampoco cambio significativamente por efecto del pastoreo. Sin embargo, la densidad de semillas de una especie de graminea anual, Muhlenbergia peruviana, aumento, mientras que la densidad de semillas de una especie de pasto perenne de gran tamano, Deyeuxia hieronymi, disminuyo significativamente con el pastoreo. Las semillas contenidas en la hojarasca de los sitios excluidos al pastoreo comprendio el 20 % del total de especies y el 43 % de la abundancia total de semillas del banco. El analisis de ordenamiento de las parcelas en funcion de la composicion floristica de la vegetacion y el banco de semillas germinable, evidencio una mayor segregacion de las parcelas en funcion del pastoreo y, en menor medida, debido a diferencias entre vegetacion y banco de semillas. Tanto en los sitios pastoreados como en los sitios excluidos al ganado predominaron las especies con banco de semillas transitorio, seguidas de especies con banco de semillas persistente a corto y a largo plazo. El pastoreo, o su ausencia, no modifica la abundancia en el banco de semillas de la mayoria de las especies, sin embargo, las dos especies que si cambian de manera importante su presencia en el banco, responden a dos estrategias opuestas, segun lo observado por otros autores, una domina la productividad primaria del ecosistema en ausencia del pastoreo, la otra, ocuparia un papel importante en la cicatrizacion de huecos a la escala de microparche en sitios muy perturbados

Impact of Ligustrum lucidum on the soil seed bank in invaded subtropical seasonally dry woodlands (Córdoba, Argentina)

The impact of invasive species on below ground flora may differ from that on the above ground vegetation. Recent reviews of invaded and native communities emphasize the need for more comprehensive information on the impacts of plant invasion on soil seed banks. Ligustrum lucidum is one of the most important invasive woody species in several ecosystems of Argentina; however, its impact on soil seed bank communities has not been studied. Here we analyzed differences in species richness, total seed density and species composition (total, native and exotic species) in the soil seed bank of native and invaded woodlands, in two different seasons. We also analyzed differences in similarity between standing vegetation and soil seed banks of both woodland types. The study was carried out in the Chaco Serrano woodlands of Córdoba, central Argentina. Our main results indicate differences in L. lucidum woodland composition and a reduction in both richness and total density of species in the soil seed bank compared to the native woodlands, independently of the sampling season. Moreover, a higher abundance of certain exotic species in the soil seed bank was observed in L. lucidum woodlands, particularly in spring. Finally, low similarity between soil seed bank and the established vegetation was observed in both woodland types. From a management perspective, it seems that passive restoration from soil seed banks of L. lucidum might be coupled with active addition of some native woody species and control of other exotic species.

Similarities in recruitment but differences in persistence in two related native and invasive trees: relevance of regenerative and vegetative attributes.

Ecological theory predicts that the success of exotic plants in new environments depends on a combination of both regenerative and vegetative attributes. Identifying those attributes may benefit from approaches that specifically compare related exotic and native species, thereby overcoming strong habitat dependence and phylogenetic bias. Gleditsia triacanthos L. (Fabaceae) is described as an aggressive woody invader in a broad range of ecosystems of Argentina, where it coexists with other leguminous trees. In the present study, we assessed whether the success of G. triacanthos in the lower areas of Chaco woodlands of central Argentina is determined (1) by differences from the dominant native, Prosopis alba, in its combination of several attributes that enhance the invader’s competitive ability, (2) by differences from P. alba in few key attributes that facilitate its spread, or (3) by strong functional similarities in response to environmental filtering by the invaded system. Our comparison of 19 functional traits of both species showed that regenerative and vegetative trends may vary independently, and that two contrasting strategies seem to underlie the success of G. triacanthos in this region. On the one hand, the invader might benefit by sharing regenerative attributes with the native relative that dominates the community, which is evidently a successful way of recruiting in the system. On the other hand, as recruitment is ensured, the species differs in several vegetative attributes, which may enhance its competitive ability in terms of growth rates and nutrient uptake.

Seed mass, seed production, germination and seedling traits in two phenological types of Bidens pilosa (Asteraceae)

Bidens pilosa L. is a summer annual that shows a particular phenological pattern in the C´ ordoba mountains, Argentina. Some individuals start flowering 1 month after germination (early type), but most of the population starts flowering 4 months after germination (normal type). The aims of this study were to (1) analyse whether differences in flowering phenology affect seed mass and seed production, and (2) assess whether possible differences in seed traits of the two parental phenological types would affect germinability, germination rate, seedling growth and flowering phenology of offspring under laboratory conditions. The study showed that the numbers of seeds per capitulum and per plant were greater in the normal type than in the early type plants. This can be related to plant height, since in the field, normal-type plants are larger than early type plants. However, early type plants produced heavier seeds than normal-type plants. Germination rate was faster in the early type seeds, but total germination was higher in the normal ones. Seedling growth, in terms of height and the date of first flowering, did not differ between the phenological types of parental seed sources. Our results showed that differences in flowering phenology were associated with seed mass and seed production differences. Seed mass appears to be related to germination characteristics but not to seedling growth nor to flowering phenology of offspring.

Floristic relations and regenerative traits in Apurimacia dolichocarpa (Fabaceae), an endemic species of central Argentina Relaciones florísticas y características regenerativas en Apurimacia dolichocarpa (Fabaceae), especie endémica del centro de Argentina

Fil: Funes, Guillermo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto Multidisciplinario de Biologia Vegetal. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Instituto Multidisciplinario de Biologia Vegetal; Argentina