Incendios en ecosistemas del norte de Suramérica: avances en la ecología del fuego tropical en Colombia, Ecuador y Perú

2020

Preprint

Questions 14Fire suppression policies have been widely adopted in the páramo grasslands of the northern 15Andes to protect their biodiversity and ecosystem services. Páramos have been regularly 16 burned for many years, and it is not clear how páramo vegetation will respond to significant 17 changes in their fire regimes. This study investigates differences in plant growth form 18 composition, light levels and soil temperatures in páramo plots representing a range of 19 recovery times since the last fire. 20 Location 21Reserva Ecológica El Ángel and La Bretaña Nature Reserve, Carchi, Northern Ecuador. 22 Methods 23We assessed the frequency of ten páramo growth forms, vegetation height, soil temperature, 24 and light intensity in fifteen fire sites with historical records of fire (<1 -15 years since fire), and 25 one recently unburned site (at least 40 years since fire). A chronosquence of sites was used to 26 assess potential changes in plant community composition in post-fire succession of páramo. 27 Results 28The recovery of páramo vegetation after fire comprised three phases: initial recruitment with 29 high growth form diversity, followed by reduced diversity, light and soil temperatures in dense 30 tussock vegetation, and ultimately canopy height stratification with a return of diversity. All but 31 one plant growth forms were represented in each of the three phases, and the changes 32 reflected differences in relative abundance. 33 Conclusions 34Post-fire páramo succession is characterized by clear shifts in the relative abundance of plant 35 growth forms, ending with (co-)dominance of upright shrubs. The long-term consequences of 36 such shifts for biodiversity and ecosystem function, given the widespread adoption of fire 37 suppression policies in the páramo need careful, evidence-based consideration. 38

Section: Phase 3 281mentioning

confidence: 99%

Section: Introduction 41mentioning

confidence: 99%

Post-fire changes in plant growth form composition in Andean páramo grassland

2020

Preprint

“…From an ecological perspective, the existence of páramo without fire is a relatively recent and rare phenomena (White, 2013) and is only beginning to be studied. If fire suppression does lead to the transition from grass páramo to a shrub‐dominated páramo with potentially altered ecosystem function, the potential consequences are of conservation concern and should be evaluated (Matson & Bart, 2013; Armenteras et al, 2020). It is important to recognise that conservation‐motivated policies to exclude fire in páramo areas might result in different ecological outcomes from those desired by the policy makers.…”

Section: Discussionmentioning

confidence: 99%

“…Fires are the most significant human impact in the páramos (Laegaard, 1992; Ramsay & Oxley, 1996; Horn & Kappelle, 2009), and people have burned these grasslands for thousands of years (White, 2013). Putative fire suppression policies have been introduced to counter a reported increase in burning frequencies in some areas (Armenteras et al, 2020), a conservation strategy that stems from the common perception of fire as a threat to ecosystem integrity and services in the high Andes (Keating, 2007; Horn & Kappelle, 2009; Matson & Bart, 2013). Understanding biodiversity and community‐level responses to such strategic decisions in the páramo requires an in depth knowledge of both fire regimes and how páramo vegetation recovers through time after fire (Ramsay, 2001; Matson & Bart, 2013).…”

Section: Introductionmentioning

confidence: 99%

Post‐fire changes in plant growth form composition and diversity in Andean páramo grassland

Applied Vegetation Science

2020

Questions Fire suppression policies have been widely adopted in the páramo grasslands of the northern Andes to protect their biodiversity and ecosystem services. Páramos have been regularly burned for many years, and it is not clear how páramo vegetation will respond to significant changes in their fire regimes. This study investigates differences in plant growth form composition, light levels and soil temperatures in páramo plots representing a range of recovery times since the last fire. Location Reserva Ecológica El Ángel and La Bretaña Nature Reserve, Carchi, Northern Ecuador. Methods We assessed the frequency of ten páramo growth forms, vegetation height, soil temperature, and light intensity in fifteen fire sites with historical records of fire (<1–15 years since fire), and one recently unburned site (at least 40 years since fire). A chronosequence of sites was used to assess potential changes in plant community composition in post‐fire succession of páramo. Results The recovery of páramo vegetation after fire comprised three phases: initial recruitment with high growth form diversity, followed by reduced diversity, light and soil temperatures in dense tussock vegetation, and ultimately canopy height stratification with a return of diversity. All but one of the plant growth forms were represented in each of the three phases, and the changes reflected differences in relative abundance. Conclusions Post‐fire páramo succession is characterised by clear shifts in the relative abundance of plant growth forms, ending with (co‐)dominance of upright shrubs. The long‐term consequences of such shifts for biodiversity and ecosystem function, given the widespread adoption of fire suppression policies in the páramo, need careful, evidence‐based consideration.

“…Land use in the páramos has shifted in the last two decades, with an intensification of 53 agricultural and recreational use, putting significant pressure on these ecologically 54 important, high diversity systems (Armenteras et al 2020;Ramsay 2014). As a response, 55 some páramo regions have adopted a fire suppression management strategy to conserve 56 páramo ecosystem integrity and function.…”

Section: Introduction 39mentioning

confidence: 99%

The impact of fire intensity on plant growth forms in high-altitude Andean grassland

2020

Preprint

16Fires in the páramo grasslands of the tropical northern Andes vary in intensity at the 17 landscape scale. Fire suppression strategies, intended to conserve biodiversity and páramo 18 ecosystem integrity and function, could lead to the accumulation of high fuel loads and 19 ultimately fires of higher intensity. Yet the impact of fire intensity on páramos is not well 20 studied or understood. 5½ years after a fire, we measured plant growth form composition, 21 light transmission to the ground and soil temperature in plots representing very high, high, 22 medium, and low fire intensities, plus a "control" that had been unburned for at least 40 23 years. We also assessed Espeletia rosette diameters, heights, population density, and 24 mortality. The low intensity plot, with a closed canopy of vegetation and lower growth 25 form diversity, contrasted with the very high intensity plot, with patchy vegetation cover 26 and higher growth form diversity. The high intensity plot had shorter Espeletia plants with 27 smaller rosettes. Light transmission to the ground increased with fire intensity, as did soil 28 temperatures. We demonstrate that the same fire can produce different 29 microenvironmental conditions, plant communities, and population structures in different 30 parts of the same fire event. In future, fire suppression could provoke more intense fires 31 with consequences for ecosystem function and service provision. Since intensity is 32 determined by a complex interaction of factors, we advocate a field programme of 33 experimental fires for a better understanding of páramo fire ecology and to guide effective 34 páramo conservation strategies. 35