The role of topography in long-term climate–fire–vegetation nexuses remains understudied, particularly in the boreal mixedwood lowlands of eastern Canada due to limited accessibility and scarcity of lake-sediment archives on hills. Yet, reconstructing paleoenvironmental conditions on hills is essential to understand long-term boreal landscape dynamics along the entire elevation gradient. We reconstructed fire activity and vegetation dynamics during the Holocene on hills in northwestern Quebec (Canada). To do so, we analyzed sedimentary charcoal particles and pollen grains from two lakes located above 460 m a.s.l. on the Abijévis Hills of Aiguebelle National Park. We then compared our fire and vegetation reconstructions with paleo-records from previous lake-sediment studies conducted on other hills and in the lowlands across the boreal mixedwood forest of the Abitibi Clay Belt region. The earliest pollen-based evidence of vegetation was recorded on hilltops around 9,900 cal. yr BP, when hills formed islands within proglacial Lake Ojibway. Fire activity began a few centuries later, before the drainage of Lake Ojibway, as revealed by increased charcoal accumulation rates. Low tree density and limited fuel availability during the early Holocene open woodland phase constrained fire activity to low levels. Fire occurrence increased after 6,500 cal. yr BP during the mid-Holocene in pine–dominated forests, and during the late Holocene in spruce–moss forests. In the lowlands, fire activity began ca. 8,000 cal. yr BP, after the drainage of Lake Ojibway. Fire frequency remained lower than on hills during the mid-Holocene, before it increased from 5,000 to 1,000 cal. yr BP. Throughout the Holocene, vegetation dynamics diverged between hills and lowlands, except for Pinus strobus, whose long‑term abundance patterns were correlated between both landscapes. Nevertheless, Pinus spp. was consistently more abundant on hills, whereas Cupressaceae and Alnus incana subsp. rugosa were more abundant in the lowlands. We have shown that topography had a predominant role in shaping Holocene fire regimes and vegetation composition in northwestern Quebec’s boreal mixedwood forests. Hills were generally more fire prone, especially between 8,400 and 4,200 cal. yr BP, likely reflecting drier fuel conditions and greater exposure associated with elevated topography. Cooler and drier conditions during the late Holocene reduced the difference in fire regimes between hills and lowlands, as the occurrence of high-severity fires increased in the lowlands. A French abstract is provided in the SI.
Termites, like other pattern-generating organisms, often create vegetation heterogeneity. The vegetation and nutrient profiles of termite mounds shape local distributions of biodiversity. Yet, little is known about how termite mounds’ effects scale to shape landscape-level biodiversity distributions. We investigated how termite mounds influence bird distributions at the species and community levels within and across three ecosystems in a human-modified African savanna landscape. In particular, we aimed to determine whether termite mounds’ effects on birds persist in agricultural areas and whether termite mounds influence the similarity of bird communities across ecosystems. We conducted point counts of birds in three ecosystems (Acacia-dominated savanna, saline grassland, and agriculture) in and around Gorongosa National Park, Mozambique. We classified birds’ use of mound or matrix (non-mound) vegetation to quantify the influence of termite mounds on bird diversity and abundance. Several bird species show significant associations with either mound or matrix vegetation. At the community level, mounds show higher bird species richness and abundance than does the matrix in all ecosystems, including agriculture. Across ecosystems, bird communities on mounds are more similar to each other than are the matrix bird communities. In agriculture, more savanna matrix-associated species are lost than savanna mound-associated species. Termite mounds influence the distribution of bird communities at the species and community levels, within natural and human-modified ecosystems, and their effects scale to influence similarity between ecosystems. The fine-scale vegetation heterogeneity created by termite mounds has multi-scale consequences for bird communities, including in human-modified parts of this African savanna landscape.
Biological invasions are deemed to be the second most important global driver of biodiversity loss showing strong interactions with the aftermaths of land use change and landscape fragmentation. The role of landscape composition and configuration in biological invasions is widely considered while its interplay with landscape connectivity is less understood. However, ecological connectivity can be equally crucial for both native and alien species, constituting the backbone of ecological network initiatives. We aim to assess how landscape composition, configuration and connectivity (in the ecological network) influence α- and β-diversity (floristic uniqueness) of both alien and native plant species, and to determine whether these effects differ according to habitat type. The study was conducted in a 298 km2 ecological network in the lowlands of Friuli Venezia Giulia, northeastern Italy, encompassing a mosaic of agricultural, natural, and semi-natural habitats. A hierarchical sampling design was applied to 87 terrestrial habitat nodes, where plant species composition and abundance were recorded in 219 plots. Landscape composition, configuration and connectivity were quantified to examine their influence on native and alien plant α- and β-diversity across different habitat types. We found contrasting effects of landscape connectivity, composition and configuration for native and alien species. Peripheral, less connected sites favored native species richness (α-diversity) and contributed to maintaining native floristic uniqueness (high β-diversity). In contrast, alien species richness was mainly associated with landscape composition and configuration, particularly the proportion of natural land use and edge-related effects in wooded habitats, while plots with higher alien richness showed lower compositional uniqueness within the alien species pool. Landscape composition and configuration also influenced invasion dynamics, as nodes surrounded by a high proportion of natural land uses with simple shapes helped contain plant invasions while preserving native richness and uniqueness. These patterns were often habitat-dependent, with stronger effects observed in wooded areas, where alien α-diversity increased with fragmentation, whereas native species richness declined. Our findings suggest that managing landscape connectivity and reducing fragmentation can enhance resistance to invasions and support native species richness. Peripheral nodes may act as native refugia, supporting high native richness and floristic uniqueness, while more accessible central nodes may function as alien hubs associated with greater alien compositional uniqueness and potential propagule exchange. Shifting from intensive to extensive land uses through green infrastructures provides a win–win strategy, promoting native species and limit alien establishment.
Urban and nearby non-urban landscapes differ in vegetation and surface climate. How these differences vary with hydroclimate over multiple decades remains poorly resolved. We compared urban and reference greenness and land surface temperature across U.S. climates. We also evaluated differences in trajectories, spatial variability, and precipitation dependence. We analyzed harmonized Landsat observations for 52 U.S. city–reference pairs over 1995–2024. Comparisons used fixed footprints, environmental covariates, and supplementary sensitivity analyses. Across 52 pairs, the median city was less green (ΔNDVI = − 0.17) and warmer (ΔLST = + 5.09 °C) than its reference. These differences reversed along the climatic gradient, with arid cities often greener and cooler and mesic cities generally less green and warmer than their references. In paired annual composites, cities warmed approximately 22
Although mangrove nature-based solutions are important for climate mitigation, coastal resilience, and livelihood support, implementation remains constrained by the lack of relevant evidence linking ecosystem conditions to benefits for people. We developed a collaborative framework to co-design mangrove nature-based solutions in Placencia, Belize, to identify community-prioritized areas for mangrove restoration and protection and quantify the ecosystem service benefits associated with these priorities. We combined participatory mapping with high-resolution habitat mapping to define priority restoration and protection areas. We used modeling to quantify changes in blue carbon, spiny lobster fisheries, tourism and recreation, and sociocultural values. Communities identified 83 hectares (ha) for restoration, which could sequester 18,500 MgC over 10 years (≈US644,000), increase lobster catch by 640 lbs yr⁻1 (≈US5,000), and generate US32,000 yr⁻1 in tourism expenditure. Protecting 174 ha of healthy mangroves could safeguard 69,500 MgC over 10 years (≈US2 million), 1,400 lbs yr⁻1 (≈US11,000) of lobster production, and US5,400 yr⁻1 in tourism expenditure. The Placencia Lagoon Management Plan could maintain 752 ha of mangrove, 1.2 million MgC over 10 years (≈US32 million), 10,000 lbs yr⁻1 (≈US80,000) of lobster catch, and US23,000 yr⁻1 in tourism expenditure. Beauty and recreation were key sociocultural values in each scenario. Our results demonstrate that integrating community knowledge with fine-scale spatial analysis can deliver measurable ecological and socioeconomic benefits that improve the design of investment-ready nature-based solutions while aligning with local and national priorities.
