Diress Tsegaye Alemu
Research Scientist
Attachments
CVBiography
I hold a PhD degree in Management of Natural Resource Management (2010) at the Norwegian University of Life Sciences (NMBU), Norway. I have over 20 years of international research and teaching experience in ecology and management of natural resources. previously, I worked a researcher at the University of Oslo and NMBU from July 2010- February 2023. My research focuses on patterns and processes in agricultural and natural landscapes, climate change, land use/cover analysis,, biodiversity conservation, and wildlife management. Highly skilled with long-term experiences in organizing, and analyzing ecological data and presenting results to a high standard. Published more than 50 papers and technical reports, of which 42 are peer-reviewed scientific journal articles. I have strong modelling/statistical data analysis background with very good skills in R'/Rstudio programming, ArcGIS, and QGIS softwares. I also possess project leadership with interdisciplinary multicultural teams.
Authors
Desalegn Chala Diress Tsegaye Alemu Habtamu Alem Belachew Asalf Tadesse Melesse Eshetu_Moges Nega Tassie Abate Ayalew Wondie Aklilu Tilahun Tadesse Abebayehu Aticho Alemu Gonsamo Lanhui Wang Erick Lundgren Jeffrey Kerby Jens Christian SvenningAbstract
Abstract Water hyacinth is among the world’s most damaging aquatic invasive plants, forming dense mats that disrupt ecosystem functioning, fisheries, navigation, and livelihoods across tropical and subtropical freshwater systems. Its rapid spread is driven by clonal propagation, short life cycles, and prolific seed production, particularly under nutrient-enriched conditions. Although mechanical, chemical, and biological control methods are widely applied, their long-term effectiveness remains uncertain when underlying eutrophication persists. Here, we present a large-scale, one-time water hyacinth removal campaign in Lake Tana, Ethiopia’s largest lake and a UNESCO Biosphere Reserve, as a representative nutrient-rich tropical freshwater system. Using high-resolution satellite imagery, we quantified coverage one month before removal, one month after removal, and one year later. We integrated SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis with a socio-ecological system map to assess mitigation mechanisms and identify sustainable management pathways capable of providing long-term solutions to halt water hyacinth proliferation in freshwater bodies. The campaign removed over 75% (~1271 ha) of water hyacinth, yet within one year the plant resurged to levels ~18% higher than pre-removal. This rebound highlights the ecological resilience of water hyacinth and the limitations of short term, noncontinuous control strategies. Our analysis identifies unmanaged catchment nutrient inputs as the primary driver of proliferation. Lake Tana serves as a model system demonstrating that water hyacinth functions less as a traditional invader and more as a bioindicator of eutrophication. We propose a transferable conceptual and methodological framework combining continuous removal, catchment-based nutrient management, and circular bioeconomy approaches, offering globally relevant lessons for sustainable management of nutrient-enriched tropical freshwater systems.
Abstract
Fuglebestandene i det norske jordbrukslandskapet går tilbake. Nye tall fra 3Q-programmet viser en nedgang på rundt 25 prosent siden 2000. Utviklingen tyder på at endringer i arealbruk og driftsformer påvirker leveområdene til mange arter, og viser behovet for målrettede tiltak for et mer variert jordbrukslandskap.
Authors
Habtamu Alem Diress Tsegaye Alemu Ibrahim Issifu Daniel D.N. Nortey Linda Bana Denis W. Aheto Belachew Gizachew ZelekeAbstract
Mangrove condition reflects interactions among ecological pressures, livelihood dependence, institutional arrangements, and biophysical constraints on regeneration. This study compares seven purposively selected rapid-appraisal sites in Ghana's Greater Amanzule Wetlands in the Western Region and the Lower Volta Delta. Evidence combines May 2025 site appraisals, 14 semi-structured interviews, three group discussions, spatial and secondary ecological information, and historical livelihood context from GLSS7 (2016–2017). Institutional functioning was assessed descriptively through rule recognition and participation, monitoring and responses to violations, and collective action, without assigning unsupported site-level scores. Visible disturbance was lower in the Western sites, with a median score of 2 (range 2–3), than in the Lower Volta sites, where the median was 4. Stakeholder accounts also indicated more consistently recognised rules and participation in the Western system, while implementation was described as less consistent in the Lower Volta. Monitoring responsibilities, frequency, and responses to violations were insufficiently documented in both systems, preventing comparison of monitoring effectiveness. Because governance evidence was primarily regional and sites were purposively selected, these findings represent a descriptive association between two coastal systems, not seven independent institutional observations or a causal institutional effect. Hydrology, hydroperiod, sediment supply, salinity, geomorphology, and the scale of pressure also condition disturbance and regeneration opportunities. Effective responses should therefore combine participatory rule implementation, collective action, transparent monitoring arrangements, livelihood measures, and restoration strategies matched to local biophysical conditions and the geographical scale of dominant stressors.
