Assessing impacts to primary productivity at the park edge in Murchison Falls Conservation Area, Uganda

Abstract

Abstract. Human activities around parks can alter vegetation patterns within them, resulting in edge effects that degrade their ability to sustain ecological processes and support biodiversity. We quantified vegetation patterns and edge effects over a large geographic extent in Murchison Falls Conservation Area, Uganda, using freely available remotely sensed data. Over a 13-yr period, we quantified seasonal patterns in productivity using the Normalized Difference Vegetation Index (NDVI), comparing the park exterior, a boundary zone ≤10 km from the border inside the park, and the park interior. To identify the extent of edge effects, we further fit mixed models by vegetation type within 1-km bands within the boundary zone. Productivity was higher in the park interior than exterior in both wet and dry seasons, and in the wet season, it was also lower in the boundary zone than the interior. NDVI variability differed between seasons; it declined from exterior to interior in the wet season, but was highest in the boundary zone and similar between interior and exterior during the dry season. Within the boundary zone, edge effects varied by land cover type and extended 4-6 km into MFCA. Abrupt differences in vegetation patterns between the park and adjacent unprotected areas indicated a "hard edge" in this system. While hard edges are readily apparent, the subtle changes in productivity that extend into and degrade park systems are harder to detect. We demonstrated a low-cost and novel approach to detect such effects using readily available satellite imagery, which indicated human influence affecting 29-40% of the park. As human populations grow, parks will become further isolated, and measuring and managing edge effects may be crucial to achieving conservation objectives.

Male-Biased Partial Migration in a Giraffe Population

“…The park is bisected by the Victoria Nile River, with the southern portion dominated by dense forest and the northern portion characterized by savanna, Borassus palm woodland, and riverine woodland. The average annual rainfall for MFNP ranges from ∼1,100-1,500 mm and is bimodally distributed with the short rains occurring from mid-March to June and August to December, and with the long dry season occurring from late-December to mid-March (Fuda et al, 2016).The current natural distribution of giraffe is limited to the northern portion of the park. Northern MFNP is divided into a series of management sectors, which roughly correspond with drainages and habitat type.…”

Mercury Contamination and Spill-Over at Human-Wildlife-Environment Interface

“…Pollution attributed to expedition for energy in Uganda and world over is closely linked to several health burdens to animals, humans, and environment [24]. This evidence can be much more pronounced in the potentially toxic substances, which have been documented to cause cancers in animals and human populations [19,23,25].…”