Woody plant species diversity as a predictor of ecosystem services in a social–ecological system of southwestern Ethiopia

Abstract

Context Human-dominated landscapes in the tropics need to be managed for biodiversity and the maintenance of ecosystem services (ES). Nevertheless, integrating both biodiversity conservation and ES management remains a challenge. Objectives This study aimed to quantify woody plant species diversity and associated ES in farmland and forests, and investigate the relationship between species and ES diversity. Methods The study was conducted in southwestern Ethiopia. We surveyed woody plants in 181 20 m by 20 m plots in farmland, forest with, and forest without coffee management. We also interviewed 180 randomly selected households about woody plant benefits. We then (a) quantified species and ES diversity; and (b) investigated the relationship between species and ES diversity. Results We recorded 128 woody plant species in total. Most ES were available in all land uses, although they differed in their mean availability. ES composition was significantly different among land uses. ES diversity was positively related with species diversity in all land uses. Conclusions Our findings suggest that all examined land-use types were multifunctional in terms of key ES provided by woody plants and that maintaining high species diversity also benefits ES diversity. Given these findings, we suggest to: (1) strengthen landscape multifunctionality by drawing on the positive relationship between biodiversity and ES diversity; (2) devise conservation policies that encompass entire landscape mosaics and enhance co-benefits of conservation and ES provision across land uses; and (3) conduct further social–ecological studies that use mixed data to elicit socially relevant relationships between biodiversity and ES diversity.

Scientists' warning to humanity on tree extinctions

“…,Labrière et al (2015) surveyed a range of different land use types in a mosaic of vegetation, including areas with swidden agriculture, rubber tapping and logging and found that tree species diversity and ecosystem service production were highest in natural forests. In southwestern Ethiopia,Shumi et al (2021) found that the diversity of ecosystem services was positively related to the diversity of tree species present, a finding that was replicated byHimes et al (2020) in the Pacific Northwest, USA.Similarly,Balvanera et al (2014) summarised evidence indicating a positive relationship between the ecosystem service of timber production and tree species richness. Research undertaken byAlbrich et al (2018) in the Austrian Alps demonstrated a further aspect of this relationship: Tree species diversity had a positive effect on the stability of ecosystem service provision over time.…”

A social-ecological assessment of food security and biodiversity conservation in Ethiopia

“…To analyse woody plant diversity, species were grouped into forest specialists, pioneers, and generalists. Data were analysed using constrained correspondence analysis, non-metric multidimensional scaling and generalized linear mixed effects models (Shumi et al 2018(Shumi et al , 2019b(Shumi et al , 2020. Additionally, birds were surveyed in forest (n = 66 sites) and farmland (n = 83 sites), using point counts, and were grouped by ecological traits (Rodrigues et al 2018).…”

“…This specific focus on woody plants was chosen because trees and shrubs are directly used by most local people; other elements of biodiversity may also be useful but not in the same immediate and direct ways (for example, wild mammals are not usually hunted here, unlike in many other parts of Africa). Finally, we combined our data on tree diversity and uses, and used regression modelling to visualise the relationship between woody species diversity and ecosystem services diversity (Shumi et al 2020).…”

“…Trees provided vital services, with 95 tree species used for 11 general purposes (Table 1) (Shumi et al 2019a). Notably, the diversity of ecosystem services in a given plot of land was positively associated with the diversity of woody species in that plot, suggesting a synergy between biodiversity conservation and landscape multifunctionality (Shumi et al 2020). Ecosystem disservices were experienced mainly through wildlife that damaged crops and livestock, and this indirectly also affected people's health, social relationships, education and incomes (Dorresteijn et al 2017).…”

Spatial predictions for the distribution of woody plant species under different land-use scenarios in southwestern Ethiopia

“…They support many other species including globally significant populations of birds and mammals and thereby contribute significantly to local biodiversity (e.g., Gove et al 2008;Hylander and Nemomissa 2008). They also contribute to multiple ecosystem services, such as house construction, farm implements, poles and timber, fuel wood, animal fodder, soil fertilization and honey production, that support the livelihoods of local people (e.g., Ango et al 2014;Shumi et al 2021).…”