The Response of Zigadenus fremontii to Variation in Fire Regime

California\u27s chaparral shrub communities are naturally exposed to dry-season fire. It could be reasoned that prescription burns set during the wet season by land managers would have more detrimental effects on plant regeneration than dry season fires because wet season burns are more likely to kill newly emergent seedlings and damage newly emerged leaves of mature plants. Six field sites with flowering Zigadenus fremontii, an herbaceous perennial geophyte common to chapparal and part of the post-fire bloom, were established at Henry W. Coe State Park in Nothern California. Three sites were part of the September 2007 Lick Wildfire and three were part of a February 2007 prescription burn. The sites were monitored for Z. fremontii regeneration over two years. Z. fremontii exposed to the prescription burn fared better than the wildfire plants, with inflorescence height being significantly higher in prescribed burn sites. Bulbs were transplanted into soil from the prescription burn, wildfire, and unburned area to determine differences in regeneration due to soil characteristics. There were no significant differences due to soil types, but only bulbs from the prescription burn sites had the ability to produce flowers in multiple years subsequent to fire. Differences in germination rates between seeds grown in soil from the wildfire, prescription burn, and unburned soil were investigated via a controlled germination experiment. There was a trend for increased germination in burned soils compared to unburned soils. The evidence from this study suggests that geophytes can benefit from fires set outside of the natural fire season of chaparral

Towards understanding resprouting at the global scale

Understanding and predicting plant response to disturbance is of paramount importance in our changing world. Resprouting ability is often considered a simple qualitative trait and used in many ecological studies. Our aim is to show some of the complexities of resprouting while highlighting cautions that need be taken in using resprouting ability to predict vegetation responses across disturbance types and biomes. There are marked differences in resprouting depending on the disturbance type, and fire is often the most severe disturbance because it includes both defoliation and lethal temperatures. In the Mediterranean biome, there are differences in functional strategies to cope with water deficit between resprouters (dehydration avoiders) and nonresprouters (dehydration tolerators); however, there is little research to unambiguously extrapolate these results to other biomes. Furthermore, predictions of vegetation responses to changes in disturbance regimes require consideration not only of resprouting, but also other relevant traits (e.g. seeding, bark thickness) and the different correlations among traits observed in different biomes; models lacking these details would behave poorly at the global scale. Overall, the lessons learned from a given disturbance regime and biome (e.g. crown-fire Mediterranean ecosystems) can guide research in other ecosystems but should not be extrapolated at the global scale.This work was performed under the framework of the TREVOL projects (CGL2012-39938-C02-01 to J.G.P.) from the Spanish Government. A.L.J., R.B.P., A.V. and S.P. were supported by the following grants: IOS-1252232 (NSF), IOS-0845125 (NSF), CGL-2011-30531-CO2-02 (SURVIVE Project, Spain), ID-1120458 (Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, Chile), respectively

Fire and resprouting in Mediterranean ecosystems: Insights from an external biogeographical region, the mexical shrubland

7 páginas, 3 tablas.We investigated modes of regeneration of dominant species of the mexical vegetation after fire. The mexical shrubland shows a remarkable structural, morphological, and floristic similarity to Mediterranean-type vegetation and is considered a relict of the Madro-Tertiary Geoflora under a non- mediterranean climate. This vegetation provides an ideal scenario to test the role of fire in Mediterranean ecosystems because historical fire occurrence is absent and the species assembly is constituted mostly by Madro-Tertiary elements and Neotropical species (some of them, endemic species from Mexico). The existence of congeneric species of the California chaparral allows us to determine the regeneration ability of these communities after fire in relation to resprouting and seeding strategies, which are widespread modes reported in the Mediterranean-type vegetation. By the experimental application of fire in the two biogeographical groups of species, we tested the hypothesis that low resprouting ability of California congeneric species (Madro-Tertiary species) after fire would indicate that fire has played an important selective force in the resprouting habit. A low resprouting ability in the Neotropical group of species would suggest that fire has molded the set of species dominating fire-prone environments. Our results indicated that resprouting is a widespread trait in the mexical species characterized by the presence of lignotubers and burls. Resprouting can be considered an ancient trait, probably linked to losses of aboveground biomass, that became a pre-adaptation in Mediterranean fire-prone communities. The Neotropical group of species showed less ability to regenerate after fire, and small plants were more likely to die after disturbance in this group than in the Madro-Tertiary group. The resprouting feature and the seeder strategy of other species after a fire in the mexical shrubland are similar to Mediterranean-type ecosystems, emphasizing their common origin and the relevance of phylogenetic and biogeographical studies to explain current patterns of vegetation.Peer reviewe

Fire responses of bushland plants after the January 1994 wildfires in northern Sydney

In early January 1994 wildfires burned areas of bushland in northern Sydney (lat 33° 45’ S, long 151° 05’ E) in coastal south-eastern Australia. This paper reports observations of the fire responses for 828 species of bushland plants – 576 native species and 252 exotic species in the Lane Cove River and Narrabeen Lagoon catchment areas. Information recorded includes whether a species was killed by fire or resprouted post-fire, when seedlings were first observed following fire, and the times of first flowering and first fruiting (or spore production) after the fires. The estimated peaks of post-fire flowering or fruiting for a few species are given. It was not practicable to record data in all categories for all of the 828 species due to the logistical challenges involved in recording data across a large area of bushland, over a number of years. The data presented add to the growing body of knowledge on plant fire responses and will assist the management and conservation of bushland in the study areas, as well as the broader Sydney region

Tailoring restoration interventions to the grassland-savanna-forest complex in central Brazil

Made available in DSpace on 2019-09-18T00:41:29Z (GMT). No. of bitstreams: 1 Schmidtetal2019RestorationEcology.pdf: 228617 bytes, checksum: f2e62c1741a1f02b90f6b15189f85175 (MD5) Previous issue date: 2019bitstream/item/202063/1/Schmidt-et-al-2019-Restoration-Ecology.pd

Root traits explain different foraging strategies between resprouting life histories

11 páginas, 5 figuras, 2 tablas.Drought and fire are prevalent disturbances in Mediterranean ecosystems. Plant species able to regrow after severe disturbances (i. e. resprouter life history) have higher allocation to roots and higher water potential during the dry season than coexisting non-resprouting species. However, seedlings of non-resprouters have a higher survival rate after summer drought. We predict that, to counteract their shallow-rooting systems and to maximize seedling survival, non-resprouters have root traits that confer higher efficiency in soil resource acquisition than resprouters. We tested this prediction in seedlings of less than 1.5 months old. We select 13 coexisting woody species (including both resprouters and non-resprouters), grew them in a common garden and measured the following root traits: length, surface, average diameter, root tissue density (RTD), specific root length (SRL), surface:volume ratio (SVR), specific tip density (STD), tip distribution in depth, internal links ratio (ILR), and degree of branching. These root traits were compared between the two resprouting life histories using both standard cross-species and phylogenetic-informed analysis. Non-resprouters showed higher SRL and longer, thinner and more branched laterals, especially in the upper soil layers. The external links (i. e. the most absorptive root region) were also more abundant, longer, thinner and with higher SVR for non-resprouters. The results were supported by the phylogenetic-informed analysis for the root traits most strongly related to soil resource acquisition (SRL, SVR and branching pattern). The seedling root structure of non-resprouters species allows them to more efficiently explore the upper soil layer, whereas seedling roots of resprouters will permit both carbon storage and deep soil penetration.We thank all the volunteers for their help in the common garden and laboratory tasks, especially H. Simo˜es, J. Bandeira, C. Pérez-Cervelló, S. Ribeiro and B. Moreira. The Banc de Llavors Forestals of Generalitat Valenciana provided the installations for the common garden experiment. This work has been financed by the Spanish projects SINREG (REN2003-07198-C02-02/GLO), PERSIST (CGL2006-07126/BOS), and GRACCIE (CONSOLIDER– Ingenio 2010 program; CSD200-00067). CEAM is supported by the Generalitat Valencia and Bancaixa; CIDE is supported by the Generalitat Valencia and the University of Valencia.Peer reviewe

Resprouting in Tropical Rainforest of Highwavy Mountains, Western Ghats, Tamil Nadu, India

Six hectares of evergreen forest of Highwavy Mountains, Western Ghats, Theni District, Tamil Nadu, India, was censused for the damaged trees (≥ 30cm girth at breast height). Among 57 damaged trees 28.07% was uprooted and 71.93% was standing broken stems. Among standing broken stems only 39.02% was resprouted. The percentage of resprouting of our study site was slightly higher than other forests. The resprouting and the production of multishoots from the stumps were mainly seen in the pioneer species and resprouting was rare in the climax species. This was contrast to other forests. Key words: resprouting, stumps, tree damage, rainforest, Western Ghats

Canopy recovery after drought dieback in holm-oak Mediterranean forests of Catalonia (NE Spain)

Climate change is likely to produce more frequent and longer droughts in the Mediterranean region, like that of 1994, which produced important changes in the Quercus ilex forests, with up to 76% of the trees showing complete canopy dieback. At the landscape level, a mosaic of responses to the drought was observed, linked to the distribution of lithological substrates. Damage to the dominant tree species (Q. ilex) and the most common understorey shrub (Erica arborea) was more noticeable on the compact substrates (breccia) than on the fissured ones (schist). This result was consistent with observations documenting deeper root penetration in schist than in breccia materials, allowing the plants growing on fissured substrates to use water from deeper soil levels. Smaller plants were more vulnerable to drought than larger plants in the trees, but not in the shrubs. Overall, Q. ilex was more affected than E. arborea. The resilience of the system was evaluated from the canopy recovery 1 year after the episode. Stump and crown resprouting was fairly extensive, but the damage pattern in relation to substrate, plant size, and species remained similar. The effect of recurrent drought episodes was studied on vegetation patches of Q. ilex located on mountain slopes and surrounded by bare rock. We observed that plants that resprouted weakly after a previous drought in 1985 were more likely to die or to produce poor regeneration in 1995 than plants that had resprouted vigorously. Vegetation patches located on the lower part of the slope were also less damaged than patches situated uphill. The study provides evidence of relevant changes in forest canopy as a consequence of extreme climate events. The distribution of this effect across the landscape is mediated by lithological substrate, causing patchy patterns. The results also support the hypothesis that recurrent droughts can produce a progressive loss of resilience, by depleting the ability of surviving plants to regenerat