Land‐use history determines stand structure and tree diversity in vanilla agroforests of northeastern Madagascar

Osen, Kristina; Soazafy, Marie Rolande; Martin, Dominic A.; Wurz, Annemarie; März, Adriane; Ranarijaona, Hery Lisy Tiana; Hölscher, Dirk

doi:10.1111/avsc.12563

Cited by 26 publications

(53 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both kinds of agroforest thus resembled the land-use types they were derived from. An increase in accumulated amphibian species richness is also demonstrated from fallow-derived vanilla agroforest over fallow land, which may emphasize the rehabilitation opportunity of fallow land through agroforestry (Osen et al 2021). These findings are in line with the prediction from a recent study of Martin et al (2020) which found that the land-use history of agroforestry systems matters for biodiversity.…”

Section: Discussionmentioning

confidence: 99%

“…We further show that while agroforestry systems play a limited role for rare amphibians, they may be more important for reptile species which prefer forest-derived vanilla agroforests over shifting cultivation and fallow-derived agroforests. Supporting the maintenance of existing forest-derived vanilla agroforests while avoiding the establishment of new forest-derived vanilla agroforests, which represent a forests degradation (Martin et al 2020;Osen et al 2021), should thus be set as a priority.…”

Section: Conservation Implicationsmentioning

confidence: 99%

“…Elsewhere, the loss of canopy cover had negative impacts on amphibian and reptile species richness (Scott et al 2006). Since canopy cover differed significantly between forest-derived vanilla agroforest (higher) and fallow-derived vanilla agroforest (lower) in the same study site (Osen et al 2021), this is calling for further investigation combining habitat characteristics with species traits (Oliveira et al 2017) to elucidate the drivers of change in both species groups.…”

Section: Land-use History Of Vanilla Agroforests Affects Reptiles But Not Amphibiansmentioning

confidence: 99%

See 2 more Smart Citations

Differential responses of amphibians and reptiles to land-use change in the biodiversity hotspot of north-eastern Madagascar

Fulgence

Martin

Randriamanantena

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Large expanses of tropical rainforest have been converted into agricultural landscapes cultivated by smallholder farmers. This is also the case in north-eastern Madagascar; a region that retains a significant proportions of forest cover despite shifting hill rice cultivation and vanilla agroforestry. The region is also a global hotspot for herpetofauna diversity, but how this diversity is affected by land-use change remains largely unknown. Using a space-for-time study design to uncover land-use effects, we compared species diversity and community composition in seven prevalent land uses: unburned (old-growth forest, forest fragment, and forest-derived vanilla agroforest) and burned (fallow-derived vanilla agroforest, woody fallow, herbaceous fallow) land-use types, and rice paddy. We conducted six comprehensives, time-standardized searches across at least ten replicates of each land-use type and applied genetic barcoding to confirm species identification. We documented an outstanding diversity of endemic herpetofauna (119 species): amphibian species richness at the plot level was highest in old-growth forest and significantly lower in all other land-use types. Plot-level reptile species richness was significantly higher in the unburned land-use types than burned land-use types. For both amphibians and reptiles, the less-disturbed land-use types showed more uneven communities and particularly in old-growth forest, the species composition differed significantly from all other land-use types. Amphibians showed a higher level of forest dependency compared to reptiles (38% versus 28% of species exclusively occurred in old-growth forest). Our analyses thus revealed that the two groups respond differently to land-use change: we found less pronounced losses of reptile species richness especially in unburned agricultural habitats, suggesting that reptiles are less susceptible to land-use change than amphibians. Overall, old-growth forest harboured a unique diversity, but some species also thrived in agroforestry systems, especially if these were forest-derived. This highlights the importance of conserving old-growth forests and non-burned land-use types within the agricultural landscape.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Conservation Implicationsmentioning

confidence: 99%

Section: Land-use History Of Vanilla Agroforests Affects Reptiles But Not Amphibiansmentioning

confidence: 99%

See 1 more Smart Citation

Differential responses of amphibians and reptiles to land-use change in the biodiversity hotspot of north-eastern Madagascar

Fulgence

Martin

Randriamanantena

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Here, the biodiversity value of vanilla agroforests may depend on land-use history, meaning whether the vanilla agroforest was established at the expense of forest (forest-derived), driving forest transformation, or whether it was planted on formerly fallow land (fallow-derived), rehabilitating formerly burned land (Martin et al 2020a). However, this important distinction is hardly made in land-use research (Martin et al 2020a), but research on plants (Osen et al 2021;Raveloaritiana et al 2021) and birds (Martin et al 2021) indicates differences in species richness and composition depending on land-use history, particularly for endemics.…”

Section: Introductionmentioning

confidence: 99%

“…Overall, the landscape of north-eastern Madagascar is characterized by a mosaic of forest fragments, rice cultivation (irrigated and rainfed), vanilla agroforests, and fallow lands (Zaehringer et al 2015). Vanilla agroforests are characterized by a combination of shade trees and Vanilla planifolia plants, leading to a structurally diverse habitat with medium to high canopy closure (Osen et al 2021). Woody and herbaceous fallows and rice paddy have significantly lower or no canopy closure and structurally and taxonomically simplified vegetation (Osen et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Tropical land use drives endemic versus exotic ant communities in a global biodiversity hotspot

et al. 2021

Self Cite

View full text Add to dashboard Cite

Understanding how land-use change affects biodiversity is a fundamental step to develop effective conservation strategies in human-modified tropical landscapes. Here, we analyzed how land-use change through tropical small-scale agriculture affects endemic, exotic, and non-endemic native ant communities, focusing on vanilla landscapes in north-eastern Madagascar, a global biodiversity hotspot. First, we compared ant species richness and species composition across seven land-use types: old-growth forest, forest fragment, forest-derived vanilla agroforest, fallow-derived vanilla agroforest, woody fallow, herbaceous fallow, and rice paddy. Second, we assessed how environmental factors drive ant species richness in the agricultural matrix to identify management options that promote endemic and non-endemic native while controlling exotic ant species. We found that old-growth forest, forest fragment, and forest-derived vanilla agroforest supported the highest endemic ant species richness. Exotic ant species richness, by contrast, was lowest in old-growth forest but highest in herbaceous fallows, woody fallows, and rice paddy. Rice paddy had the lowest non-endemic native ant species richness. Ant species composition differed among land-use types, highlighting the uniqueness of old-growth forest in harboring endemic ant species which are more sensitive to disturbance. In the agricultural matrix, higher canopy closure and landscape forest cover were associated with an increase of endemic ant species richness but a decrease of exotic ant species richness. We conclude that preserving remnant forest fragments and promoting vanilla agroforests with a greater canopy closure in the agricultural matrix are important management strategies to complement the role of old-growth forests for endemic ant conservation in north-eastern Madagascar.

show abstract

Widespread introduced species dominate the urban tree assemblage on the endemic‐rich tropical island of São Tomé

Strauß,

de Lima,

Baker

et al. 2024

Ecology and Evolution

View full text Add to dashboard Cite

The Afrotropics are experiencing some of the fastest urbanisation rates on the planet but the impact of city growth on their rich and unique biodiversity remains understudied, especially compared to natural baselines. Little is also known about how introduced species influence β‐diversity in these contexts, and how patterns coincide with native ranges of species. Here we investigated how tree assemblages of the endemic‐rich Afrotropical island of São Tomé differed between urban, rural and natural zones. These were primarily characterised by urban greenspaces, shade plantations, and old‐growth forests, respectively. Based on 81 transects, we assessed biodiversity metrics of endemic, native and introduced species. Tree abundance and species richness were highest in the natural zone, where the composition was most different from the urban zone. The tree community of the rural zone was the most uneven and had the least variation among transects, representing the lowest β‐diversity. The urban zone was dominated by introduced species (57.7%), while the natural zone hosted almost exclusively native species (93.3%), including many endemics (26.1%). The biogeographic realms that species originated from were particularly diverse in the urban zone, with few species from the Afrotropics. In contrast to native and endemic trees, introduced trees were clearly associated with urban and rural expansion, as they were much more abundant and species‐rich in these zones than in the natural zone, facilitating biotic homogenisation. These findings highlight how urban and rural environments are affecting the native tree flora of São Tomé, and the need for conservation measures geared towards globally threatened and endemic tree species. Importantly, these require the protection of natural forests, despite the rising land demands for settlements and agriculture. Ultimately, such action to conserve endemic trees will contribute to global efforts to prevent further biodiversity declines.

show abstract

Land‐use history determines stand structure and tree diversity in vanilla agroforests of northeastern Madagascar

Abstract: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Cited by 26 publications

References 99 publications

Differential responses of amphibians and reptiles to land-use change in the biodiversity hotspot of north-eastern Madagascar

Differential responses of amphibians and reptiles to land-use change in the biodiversity hotspot of north-eastern Madagascar

Tropical land use drives endemic versus exotic ant communities in a global biodiversity hotspot

Widespread introduced species dominate the urban tree assemblage on the endemic‐rich tropical island of São Tomé

Contact Info

Product

Resources

About