Browsing by Author "Smith, Pete"

Now showing 1 - 2 of 2

Planting trees in livestock landscapes to protect soil and water also delivers carbon sequestration
(2023) Iñamagua Uyaguari, Juan Pablo; Smith, Pete; Fitton, Nuala
Ecuador has committed to climate change mitigation by reducing greenhouse gas emissions from anthropogenic activities, including livestock production. This sector can also contribute to mitigation by increasing carbon sequestration and storage capacity through increasing tree coverage. Although feasible, tree cover expansion would require agricultural land, creating a conflict with food production, thus appropriate areas need to be selected, and the impacts on livestock production quantified. Following water protection legislation and soil protection guidelines, we use a combination of measurements on 100 farms with land cover datasets to identify suitable areas for increasing tree coverage in livestock landscapes. Land cover classification was performed in 2 km areas around 100 livestock farms in the coastal and Amazon regions in Ecuador. Riparian zones were identified following legislation and steepland pastures identified from a slope map. Pasture in riparian areas or steeplands (slope > 15%) were considered suitable for increasing tree coverage by restoration or silvopastoral systems (SPS). The impact of forest/silvopastoral on biomass production was quantified. Overall, 855 km of rivers were studied, between 1–18% of riparian areas were classified as pastures, whilst from the 85992 ha included in the land cover classification, 41668 ha were identified as steepland, 1–28% of steepland was covered by pastures. We estimate that steepland pasture conversion into forest could offset 1.8–10% of Ecuador’s annual GHG emissions from the agricultural sector, but its impacts could represent a decrease > 50% of pasture biomass production at landscape level. Transformation of riparian and steepland pastures into SPS, could deliver important carbon sequestration, with a reduction in pasture biomass production of less than 20%.
Use of unoccupied aerial systems to characterize woody vegetation across silvopastoral systems in Ecuador
(2022) Torres, Jonatha; Sangoluisa, Pamela; Smith, Pete; Iñamagua Uyaguari, Juan Pablo; Green, David R.; Fitton, Nuala
The trees in pastures are recognized for the benefits they provide to livestock, farmers, and the environment; nevertheless, their study has been restricted to small areas, making it difficult to upscale this information to national levels. For tropical developing countries, it is particularly important to understand the contribution of these systems to national carbon budgets. However, the costs associated with performing field measurements might limit the acquisition of this information. The use of unoccupied aerial systems (UAS) for ecological surveys has proved useful for collecting information at larger scales and with significantly lower costs. This study proposes a methodology that integrates field and UAS surveys to study trees on pasture areas across different terrain conditions. Our overall objective was to test the suitability of UAS surveys to the estimation of aboveground biomass (AGB), relying mainly on open-source software. The tree heights and crown diameters were measured on 0.1-hectare circular plots installed on pasture areas on livestock farms in the Amazon and Coastal regions in Ecuador. An UAS survey was performed on 1-hectare plots containing the circular plots. Field measurements were compared against canopy-height model values and biomass estimates using the two sources of information. Our results demonstrate that UAS surveys can be useful for identifying tree spatial arrangements and provide good estimates of tree height (RMSE values ranged from 0.01 to 3.53 m), crown diameter (RMSE values ranged from 0.04 to 4.47 m), and tree density (density differences ranging from 21.5 to 64.3%), which have a direct impact on biomass estimates. The differences in biomass estimates between the UAS and the field-measured values ranged from 25 to 75%, depending on site characteristics, such as slope and tree coverage. The results suggest that UASs are reliable and feasible tools with which to study tree characteristics on pastures, covering larger areas than field methods only.