The study of land use land cover change (LULC) provides a measure of how landscapes are transformed to meet the natural resource needs of humans. Unraveling how land use constrains biodiversity and ecosystem functions, to determine the consequences of global change for mountain ecosystems, is critical for landscape planning and management to supply vital ecosystem services to millions of upland and lowland inhabitants. This understanding is particularly important for assessing impacts on tropical mountain ecosystems, where altitudinal and climatic gradients can produce sensitivities in ecosystem responses and affect the long-term provision of services and the well-being of associated human populations.
Given this issue, this research aimed to further the understanding of the impacts of land use changes on mountain systems of Northern Ecuador. To achieve this goal, we tested an adapted version of the Driver-Pressure-State-Impact-Response (DPSIR) framework for tropical mountain systems. Within this framework, I conducted an ecosystem assessment in a representative mountainous landscape of northern Ecuador with the following specific objectives: 1) characterize spatio-temporal patterns of land use, 2) reveal driving forces for the land use transitions, 3) analyze the effects of land use change on local biodiversity, ecological functions, and ecosystem services, and 4) evaluate if land use change affects the capacity to supply ecosystem services.
The study region comprises the territory of the canton of Pedro Moncayo, located in the Andean province of Pichincha, and encompasses 332 km² distributed among five parishes. It is a landscape with climatic conditions, and land use legacies characteristic of the highlands of northern Ecuador. The territory has a wide altitudinal gradient ranging from 1900 to 4000 m.a.s.l. and it encompasses a mosaic of different natural ecosystems and distinct land uses which can be described following the altitudinal gradient. The higher altitudinal zone (above 3300 m) is dominated by native ecosystems, represented by páramo and highland montane forests. The middle altitudinal area (2800-3300 m) has been extensively used for agriculture and livestock over time, causing severe soil degradation, and the lower lands are characterized by shrub-dominated dry ecosystems.
First, land use change dynamics characterized by Markov chain transition probabilities along elevation and geographic gradients revealed clear patterns. A significant expansion of floriculture (13 times) and urban areas (25 times) was found, reaching together almost 10% of the territory from 1990 to 2014 on previous agricultural land located at lower elevations in the east of the studied territory. Our findings also revealed an unexpected high probability of persistence (between 0.75 and 0.9) of páramo, but also a 40% reduction of montane forests, with the lowest probability (