African Journal of Ecology最新文献

Plant-pollinator interactions are among the most studied mutualistic interactions in terrestrial ecosystems. However, little is known about them from the agricultural landscapes within tropical forests of Africa, including the East Usambara Mountains in Tanzania. This study provides the first description of sunbird-plant pollination networks from the East Usambara Mountains. We compared the sunbird floral visitation network and pollen transport network in the agroforestry of Amani Plateau near Amani Nature Forest Reserve. For the floral visitation network, we included a network with nectar robbers and one without. Our results show that the floral visitation and pollen transport networks are structurally similar, and sunbirds visit flowering plants with a wide range of pollination syndromes. Both networks are nested, connected, and modular, so they are relatively robust and less prone to secondary extinctions. Nectar robbers affected the modularity of the network structure and confirmed the reliability of the pollen transport network in defining the most robust plant-pollinator networks. We found that sunbirds with longer beaks transport more pollen, and sunbirds can transport pollen from robbed plants. The findings of this study underscore the vital role of agricultural landscapes in conserving avian pollinators. Therefore, sustainable agricultural practices should be prioritised to mitigate agriculture's negative impact on avian pollinators.

The aim of this study was to describe and compare the dietary composition of lion (Panthera leo), cheetah (Acinonyx jubatus) and spotted hyaena (Crocuta crocuta) populations in Liwonde National Park, Malawi. Using scat analyses and direct observations, our results indicate a high degree of dietary overlap (O_ab > 0.70), indicative of intraguild competition, and all carnivores exhibited a dietary preference for kudu (Tragelaphus strepsiceros). At present, coexistence is potentially facilitated by low carnivore densities and spatiotemporal responses. We recommend that carnivore diets and niche partitioning strategies continue to be investigated as carnivore populations increase.

Tithonia rotundifolia (Miller) S. F. Blake is an invasive weed in southwestern Nigeria that displaces native flora and creates a monoculture stand. Its impact on plant species richness has led to investigations into its invasive strategies, including its allelopathic potential. The study investigated the effects of T. rotundifolia leachates and litters on the germination and growth of Corchorus olitorius L. and Amaranthus hybridus L. and the influence on the soil physicochemical properties. The germination of the vegetables in aqueous leachates of T. rotundifolia tissues, at concentrations (%) of 20, 40, 60, 80 and 100, was compared with the control (in distilled water). Different dosages (0, 10, 20, 30, 40 and 50 g) of T. rotundifolia litter were incorporated into a 3 kg of soil and used to monitor the growth of the test plants in a completely randomised design. Differences in treatment were subjected to Analysis of Variance (ANOVA) followed by Duncan's Multiple Range Test to determine significant effects. The dried leaf leachates completely inhibited germination at 60%–100%. They inhibited seedling growth more than stem, root and flower leachates (leaves > flower > root > stem). Leaf litter, at low concentrations, enhanced the growth of the vegetables; highest growth parameters obtained for A. hybridus and C. olitorius were height (65.25 ± 11.29 and 40.77 ± 2.72 cm), girth (8.64 ± 0.47 and 3.09 ± 0.13 cm) and number of leaves (24.10 ± 6.24 and 21.90 ± 5.93) at 30 g and control, respectively. The organic carbon and nitrogen composition of A. hybridus biomass were also highest at 30 g (99.54 ± 0.64 and 3.95 ± 0.02) mg kg⁻¹. T. rotundifolia litter has no significant effect on the K⁺ and Na⁺ content of the soil. The OC and TN content in A. hybridus grown soil were significantly higher (p < 0.05) above the 20 g litter dosage than the control, while OC in the control soil (3.36 ± 0.05 g kg⁻¹) was significantly higher (p < 0.05) than C. olitorius soil treated with 40 (2.60 ± 0.04 g kg⁻¹) and 50 g (2.52 ± 0.03 g kg⁻¹) litter. These results suggest that T. rotundifolia has allelopathic effects at high concentrations but may improve soil fertility and plant growth at low dosages. Although at low magnitude of the biomass it serves as soil amendment, but regular removal from the field is essential to prevent biomass accumulation that will hinder seed germination and crop growth.

The Upemba Lechwe (Kobus anselli) persists in the Kamalondo Depression in the southern Democratic Republic of the Congo. We report sightings of 10 individuals across their historical stronghold and present the first published photograph of a live specimen. This study provides the first documented records since the species was described in 2005, and the first survey attempt in over 50 years. With an estimated population likely numbering fewer than 100 in an area with little protection, this species faces imminent extinction due to poaching. Urgent conservation measures are essential to prevent its disappearance.

The Grey Francolin (Francolinus pondicerianus) was introduced to Reunion Island in the XVIIIth century for hunting purposes. This species is little known locally, as it has rarely been studied as other game birds on the island. The aim of this study was to define the current state of Grey Francolin populations on Reunion Island. We showed Grey Francolin's distribution area covers today 3500 ha and is made up of two isolated and geographically opposed zones on the island. One is located in the north of the island and is mostly made up of sugarcanes fields. The second, in the South, is a secondary dry forest. We estimated a density of 9.3 ± 2.0 singing males per km² and thus an abundance of 324 ± 41 singing males on Reunion Island. Density was higher in the southern secondary dry forest zone (10.5 ± 2.8 singing males per km²) than in the northern sugarcane fields (6.6 ± 2.0 singing males per km²). From the 1950s', the Grey Francolin's distribution has shrunk and become more fragmented. The main factors implicated are changes in farming practices (mechanisation, pesticides), excessive urbanisation and, to finish, excessive hunting and poaching (in the past).

Land degradation in semi-arid regions poses a major threat to Sustainable Development Goal 15 (SDG 15) by undermining ecosystem services and biodiversity. Although restoration strategies like exclosures are gaining attention, there remains a critical gap in quantifying their long-term ecological and carbon sequestration benefits, particularly in severely degraded landscapes such as Ethiopia's Tigray region. This study addresses that gap by comparing 15-year-old exclosures with adjacent open pasture using a mixed-methods approach. We assessed 62 plots (31 per land use type) for species diversity (Shannon-Wiener and Simpson indices), biomass (via allometric equations), soil properties (at 0–15 cm and 15–30 cm depths), and carbon stocks, employing Principal Component Analysis (PCA) and Pearson correlation. Results showed that exclosures significantly outperformed pasture, supporting 174 plant species versus 69, higher soil organic carbon (18.71 g/100 g vs. 15.91 g/100 g at 0–15 cm, p < 0.001), and greater above-ground biomass (40.72 t/ha vs. 14.24 t/ha, p < 0.001). These findings underscore the potential of exclosures as a scalable and cost-effective strategy for restoring degraded semi-arid ecosystems, offering robust empirical evidence to inform national policy integration, advance SDG 15, and support climate change mitigation across similar regions globally.