Evelien Terwel – The only way is up: Drivers of non-native species’ dispersal patterns along trails acrossthe Scandic mountains

Universiteit Utrecht

The Scandic mountains in northern Sweden are home to a wide range of unique plants and animals living in diverse ecosystems. These ecosystems are increasingly disturbed by human activity, such as hikers on mountain trails. Hikers disturb the ground and can unknowingly transport plant seeds on their shoes and clothes, enabling them to disperse to higher elevations.

Climate warming further enhances this process. Lowland and invasive plant species are often limited by cold mountain temperatures, yet climate warming can allow species to expand their range. This study examines the effects of environmental variables, including temperature and rainfall, as well as human activity, on three non-native species: Achillea millefolium, Trifolium repens, and Trifolium pratense.

In the Abisko region of northern Sweden, we monitored the occurrence of these species along hiking trails using the standardized protocol of the Mountain Invasion Research Network (MIREN). Over a ten-year period, all three species were found to move upward along the trails. Achillea millefolium showed the highest number of occurrences and dispersed to higher elevations than the two Trifolium species.

We found that temperature was the most important predictor of species dispersal and establishment. However, dispersal patterns appear to be influenced by multiple interacting factors. Many climatically suitable areas remain uncolonized, likely due to low human activity. As climate warming continues, new areas may become suitable, but colonization may remain slow where human presence is limited.

Joep van den Heuvel – Using multivariate CT-DS to assess the relation between fruit availability and the spatiotemporal distribution of frugivores

Universiteit Utrecht

Tropische bossen verschaffen ons allerlei ecosysteemdiensten, zoals koolstofopslag, waterzuivering, en een vruchtbare bodem. Frugivoren, dieren die voornamelijk fruit eten, spelen een belangrijke rol in het in stand houden van deze ecosysteemdiensten door de bos-samenstelling te beïnvloeden via zaadverspreiding. Dit onderzoek richt zich op de relatie tussen de fruitbeschikbaarheid en de spatiële verspreiding van frugivoren in een tropisch regenwoud in Frans-Guyana. Hierbij was onderscheid gemaakt worden tussen verschillende typen bos. Het onderzoek maakte gebruik van camera trap distance sampling (CT-DS), een nieuwe methode om de afstand van een dier tot de camera te schatten. Hiermee konden detectiemodellen worden gemaakt waarmee de kans op het spotten van een dier op bepaalde afstanden kon worden bepaald. In deze modellen zijn naast de beschikbaarheid van fruit omgevingsfactoren als covariaten meegenomen worden om hun invloed op de verspreiding van frugivoren te beoordelen. Het uitvinden en begrijpen van de drijfveren achter de verspreiding van frugivoren kan helpen bij het ontwikkelen van strategieën voor habitatbehoud, het aanwijzen van beschermde gebieden en het bevorderen van duurzaam beheer van tropische bossen wereldwijd.

Jip Berkelder – Transplantation as a method for (meta)population restoration: An evaluation after a 12-year monitoring period of experimental re-introduction of Anacamptis morio in Zeeland

Wageningen University and Research

This study marks the conclusion of a long-running project that monitored experimental transplantations of the green-winged orchid (Anacamptis morio) to two new locations in Zeeland. Over a 12-year period, individual plants of this food-deceptive species were recorded within permanent quadrants. This resulted in a substantial dataset that allowed us to evaluate the overall “success” of the transplantation. Annual vegetation surveys were conducted alongside the monitoring. In addition, this year, we collected leaf material in the field to perform genetic analyses on both the donor population and the transplanted populations, supplemented with three reference populations from Texel, Hompelvoet, and Zuid-Limburg. The findings suggest promising prospects for the long-term persistence of the transplanted populations. The species’ limited sensitivity to inbreeding, positive population development and good reproductive success in recipient sites, indicate good population performance. Genetic results revealed only very minor bottlenecks post-transplantation. Together, these outcomes highlight that targeted re-introductions, when ecologically informed and followed by proper monitoring can prove to be an effective tool for (meta)population restoration.

Eka Cahyaningrum – Vanilla Undercover: Shade-tree Effect on Vanilla Yield in Madagascar

Wageningen University and Research

Vanilla is one of the agroforestry commodities that are relatively tolerant of tree canopy. Unlike some other agroforestry commodities, such as coffee and cocoa, which require an open canopy, vanilla can grow under increasingly dense canopy. Research by Martin et al. (2021) states that canopy cover shade tree growth is relatively neutral to yield, thereby potentially supporting forest regeneration. However, there are still gaps in our knowledge, particularly regarding changes over time and the influence of shade tree management. This study was conducted to address these gaps and better understand how vanilla agroforestry contributes to forest restoration. The study aims to evaluate the relationship between vanilla yield, canopy cover, canopy height, planting density, and land-use history in Madagascar’s vanilla agroforestry. It will use a time-series approach and use the study by Martin et al. (2021) as the baseline. Data collection will be conducted from September to December 2025 in 10 villages in the SAVA Region in northeastern Madagascar. Parameters measured include canopy cover size, shade tree height and nativeness, agroforest size and age, planting density, and vanilla yield. Statistical analysis and comparison with relevant literature will be conducted to support subsequent reports or thesis writing.

Yukie Yokoyama – Ecological Recovery through Frugivores in Madagascar

Wageningen University and Research

Madagascar is one of the world’s top biodiversity hotspots, yet its ecosystems face growing pressure from anthropogenic activities to meet livelihood needs (Elmqvist et al., 2007; Ralimanana et al., 2002). With one-third of households’ dependent on forests for their livelihoods, forest restoration is essential for sustainable development (IIED & Foniala, 2008). Forests play a critical role in sustaining biodiversity, regulating climate, and providing essential Nature’s Contributions to People (NCPs). To enhance both long-term social and ecological forest restoration effectiveness, solution oriented research is needed to design restoration interventions that equitably deliver multiple locally demanded NCPs (Löfqvist et al., 2023).

This study aims to assess how forest restoration influences forest recovery and ecological function by looking at frugivore density and richness across different forest types and forest characteristics. 

This will be assessed through the following research questions:

1. How do different forest typologies (humid, dry and transitional) influence frugivore density and richness across restored forest sites?
2. How does forest structure influence frugivore density and richness within restored forest sites?

My research will be conducted over 60 days in two regions of Madagascar and will be deploying artificial fruits, together with camera traps, as aproxy of frugivore density and taxa richness.

Bianka Fábryová – The role of forest landscape in shaping seed communities in naturally regenerating secondary tropical forests

Wageningen University and Research

Natural forest regeneration represents a promising solution for ecological restoration of tropical forests. In this study, we analyzed the impact of surrounding forest landscape on the seed rain of woody plants in naturally regenerating secondary tropical forests. We collected seeds using seed traps in early successional plots across wet and dry tropical forests in southern Mexico. To characterize the surrounding forest landscape, we used Landsat satellite time series and the AVOCADO algorithm to map forest cover characteristics. Our results suggest that older successional forests in the surrounding landscape are essential for enhancing seed richness. Furthermore, well-connected forests may be more important in wet tropical forests dominated by biotically dispersed seeds, whereas more open landscapes may play a greater role in dry tropical forests dominated by abiotically dispersed seeds. Therefore, considering the successional stage of the surrounding forest landscape and adopting region-specific conservation plans are pivotal when aiming to naturally regenerate degraded landscapes.