Composición florística y reservas de carbono en bosques ribereños en paisajes agropecuarios de la zona seca del Tolima, Colombia Abstract: Floristic composition and carbon stocks of riparian forests in agricultural landscapes in the dry zone of Tolima, Colombia. The tropical dry forest is a typical lowland ecosystem that is threatened by a strong seasonality and anthropogenic pressures, which can affect the forest composition and structure. The objective of this study was to estimate the impact of two agricultural matrices on the floristic composition and carbon storage in riparian forests. For this, five permanent plots (10 x 10 m each) were established and sampled in the forest interior and at the edge of two agricultural matrices (rice fields and pasture lands), in July 2013. All individuals with a diameter at breast height (dbh) ≥ 5 cm were recorded and measured, and the aboveground biomass was estimated with a general allometric model. Additionally, the importance value index (IVI), species richness and Alpha´s diversity indexes were estimated; an analysis of variance and means comparison tests of Fisher LSD were also carried out. A total of 32 families, 21 genera and 45 species (29 and 33 species in pasture lands and rice fields, respectively) of trees in 0.2 ha were recorded. The most abundant and most ecologically important species were Oxandra espintana and Calliandra sp. (520 and 241 individuals/ha and 72 and 48 % of IVI, respectively). These forests presented a mean dominance of 33.9 m 2 /ha with no effect (P < 0.05) of forest location or agricultural matrix. The matrix of the landscape did not affect (P > 0.05) the Alpha diversity indexes. The biggest trees and greatest carbon storage were found in forests with pasture matrices when compared to rice fields (14.6 vs 13.4 cm of dbh and 72.9 vs 45.6 t C/ha, respectively). This research provides an understanding of the tree richness and composition and carbon storage of riparian forests in two agricultural matrices, which could be a basis for the establishment of silvopastoral systems with native species. Rev. Biol. Trop. 65 (4): 1245-1260. Epub 2017 December 01.

It was estimated the climate change adaptation of the main coffee production systems in Líbano, Tolima, Colombia, using diversity indicators. Three production systems were selected: agroforestry systems (AFS) with Cordia alliodora, AFS with plantain and in monoculture, with four replications, locating five sampling units to collect and identify the ant genera as diversity and adaptation indicators. The richness index of Margalef detected between systems (1.3 vs 0.6 vs 0.6 for AFS with C. alliodora, monoculure and AFS with plantain, respectively). The genera Cephalotes, Dorymyrmex, Hypoponera, Pachycondyla, Octostruma and Proceratium, which require abundant biomass and litter, were registered just in AFS with C. alliodora, coinciding with the depth of this layer. The AFS with C. alliodora present advantages due they improve conditions for the conservation of several groups of ants, which are indicators of diversity and climate change adaptation.

Trees are essential in the city to capture CO2, and, at the same time, to contribute to the mitigation of climate change. Carbon storage and fixation in aboveground biomass was estimated in the urban woodland of Ibagué with a census from 2013-2016, and a new measurement of 15% on individuals in the 2019-2020 period. The number of trees of the main species required to mitigate emissions of greenhouse gases from households was estimated. Urban woodland captures about 3.81 Gg CO2/year, which represents only 2,3% of the city emissions. The mitigation of 169.2 Gg CO2/year of the city households would be achieved by having between 412,000 and 1.2 million trees of the most dominant species. Efforts based on green infrastructure to compensate urban emissions at municipal level must be coordinated with territory policies at large scales.

Protected areas are important zones for the conservation of strategic ecosystems that provide environmental services to human populations. The Santuario de Fauna y Flora Iguaque (SFFI) (Boyacá, Colombia) preserves an important area of páramos and andean high-land forests that offer water and other services. Soil organic carbon (SOC) was estimated at a depth of 0–30 cm in the four dominant land uses: (1) natural grasslands prevailingly without trees and shrubs (NSWT), (2) broad-leaved forests with continuous canopy, not on mire (BFCC), (3) open heathlands and moorlands (OMH), and (4) dense heathlands and moorlands (DMH). This classification is based on Corine Land Cover, adapted for Colombia. Land uses did not differ significantly (p > 0.05) in the SOC stock, with values of 139.0, 131.1; 101.1; and 83.0 Mg C/ha in OMH, BFCC, NSWT, and DMH, respectively. In total, SFFI retains 593 Gg C in that soil layer. Projections of effects caused by potential land use changes show that up to 461.0 Gg CO2 could be transferred to the atmosphere if this conservation area is not preserved. SFFI, due to its conservation strategies, allows storing significant amounts of atmospheric carbon and becomes an effective strategy of climate change mitigation.