Páramos are exceptionally species-rich tropical alpine ecosystems that provide several important ecosystem services, including carbon storage and water provision. The responses of páramo plant species to climatic change are largely unknown, but classifying species by functional type and ecological strategy can help reduce complexity for modeling and conservation efforts. We measured 22 traits in 42 plant species with various growth forms in the Colombian Andes. We classified plant ecological strategies using CSR (C: competitor, S: stress tolerator, and R: ruderal) analysis and identified plant functional types (PFTs) using hierarchical clustering of principal components.Additionally, we calculated the functional originality of each species to identify species with unique trait combinations. We identified a high degree of convergence among traits and strategies, with most species characterized by the S and SC strategies. Considering the full set of traits, only three PFTs were identified: one composed of forbs and shrubs with tender leaves (PFT1), another composed only of species with rosettes form (PFT2), and a third composed of shrubs with tough leaves (PFT3).Values of functional originality were generally low, suggesting high redundancy in plant traits. PFT2 species, mostly rosettes, exhibited the highest functional originality of all the groups. Our results imply the existence of a limited set of ecophysiological strategies in the páramos, likely driven by the extremely stressful conditions in these systems. This functional redundancy may indicate heightened vulnerability to environmental changes; however, the presence of multiple species with shared functional traits could provide some resilience to disturbance.

Páramos, tropical alpine ecosystems, host one of the world’s most diverse alpine floras, account for the largest water reservoirs in the Andes, and some of the largest soil carbon pools worldwide. It is of global importance to understand the future of this extremely carbon-rich ecosystem in a warmer world and its role on global climate feedbacks. This study presents the result of the first in situ warming experiment in two Colombian páramos using Open-Top Chambers. We evaluated the response to warming of several ecosystem carbon balance-related processes, including decomposition, soil respiration, photosynthesis, plant productivity, and vegetation structure after 3 years of warming. We found that OTCs are an efficient warming method in the páramo, increasing mean air temperature by 1.7°C and mean daytime temperature by 3.4°C. The maximum air temperature differences between OTC and control was 23.1°C. Soil temperature increased only by 0.1°C. After 3 years of warming using 20 OTC (10 per páramo) in a randomized block design, we found no evidence that warming increased CO2 emissions from soil respiration, nor did it increase decomposition rate, photosynthesis or productivity in the two páramos studied. However, total C and N in the soil and vegetation structure are slowly changing as result of warming and changes are site dependent. In Sumapaz, shrubs, and graminoids cover increased in response to warming while in Matarredonda we observed an increase in lichen cover. Whether this change in vegetation might influence the carbon sequestration potential of the páramo needs to be further evaluated. Our results suggest that páramos ecosystems can resist an increase in temperature with no significant alteration of ecosystem carbon balance related processes in the short term. However, the long-term effect of warming could depend on the vegetation changes and how these changes alter the microbial soil composition and soil processes. The differential response among páramos suggest that the response to warming could be highly dependent on the initial conditions and therefore we urgently need more warming experiments in páramos to understand how specific site characteristics will affect their response to warming and their role in global climate feedbacks.

To effectively implement the Paris Agreement, capacity in carbon accounting must be strengthened in the developing world, and partnerships with local academic institutions can do the accounting for governments and fill the capacity gap. This paper highlights the Brazilian case, focusing on ways in which climate change science information and transparency are being incorporated in national C accounting initiatives, particularly the national inventory of greenhouse gas (GHG) emissions and removals. We report how the third inventory for the sector of land use, land-use change and forestry (LULUCF) was implemented to address scientific challenges involved in the monitoring of carbon stocks and land-use changes of diverse and complex biomes while addressing international and national policy demands (report and decision support) and transparency to various stakeholders. GHG emissions and removals associated with 2002-2010 carbon changes in aboveground, belowground biomass, necromass and soil carbon by land use and land cover changes were estimated for all Brazilian biomes, and for the Amazon estimates were also presented for the periods of 2002-2005 and 2005-2010. The inventory improved regional estimates for carbon stock and national emission factors with the support and engagement of the scientific community. Incorporation of local context is essential to reduce uncertainties and properly monitor efforts to contribute to GHG emission/reduction targets. To promote transparency and make information more accessible, the national inventory results were made available by the National Emissions Registry System (SIRENE). This system was built to support climate change policies as an important legal apparatus and by increasing access to emissions and land-use change data.

Paramos are a unique type of tropical alpine ecosystem. To understand how biodiversity, ecosystem services and community resilience in the paramo will be affected by ongoing environmental change we need to start identifying groups of species with shared characteristics (i.e. functional types or PFTs). This task is particularly challenging as paramos host the highest plant diversity of alpine ecosystems. We measured 22 traits on 42 species belonging to different growth forms in the Colombian Andes. Hierarchical Clustering on Principal Components performed in a Factor analysis of mixed data was used to identify species with similar functional traits and the number of PFTs present. We identified three PFTs; one composed of forbs and shrubs with tender leaves, one composed of only rosettes, and a third group composed by shrubs with tough leaves. If PFTs represent a group of plants that play similar roles in the ecosystem, and have similar responses to perturbation, our results imply that paramos might have limited physiological response and may be highly vulnerable to environmental changes. On the other hand, the presence of multiple species sharing functional traits could provide some resilience, if one species disappears, others may fill the same role and maintain the functionality of the paramo.

Warming shifts the thermal optimum of net photosynthesis (ToptA) to higher temperatures. However, our knowledge of this shift is mainly derived from seedlings grown in greenhouses under ambient atmospheric carbon dioxide (CO2) conditions. It is unclear whether shifts in ToptA of field-grown trees will keep pace with the temperatures predicted for the 21st century under elevated atmospheric CO2 concentrations. Here, using a whole-ecosystem warming controlled experiment under either ambient or elevated CO2 levels, we show that ToptA of mature boreal conifers increased with warming. However, shifts in ToptA did not keep pace with warming as ToptA only increased by 0.26–0.35 °C per 1 °C of warming. Net photosynthetic rates estimated at the mean growth temperature increased with warming in elevated CO2 spruce, while remaining constant in ambient CO2 spruce and in both ambient CO2 and elevated CO2 tamarack with warming. Although shifts in ToptA of these two species are insufficient to keep pace with warming, these boreal conifers can thermally acclimate photosynthesis to maintain carbon uptake in future air temperatures.