Forest fragmentation effects on mutualistic interactions: Frugivorous birds and fruiting trees

While many effects of forest fragmentation are reasonably well understood, knowledge of interspecific interactions in fragmented ecosystems is much more limited, particularly for high-diversity tropical forests. Using nearly 40 years of data from the Biological Dynamics of Forest Fragments Project in Central Amazonia, we assessed whether forest fragment area and time since isolation impact mutualistic interactions between frugivorous birds and their food resources. We used structural equation modeling to analyze the complex pathways between four main variables determining these interactions: fruiting tree abundance, frugivorous bird abundance, forest fragment area, and time since fragment isolation. Our results confirm that fragment area alters the abundance of some tree resources, with successional plant families increasing in abundance with decreasing fragment size. However, these changes do not drive alterations in the abundance of frugivorous birds. We also tested if bird species wi..., , , # Forest fragmentation effects on mutualistic interactions: Frugivorous birds and fruiting trees

#### **Description of the data and file structure**

File: “StandPlantsRawBirds” is the data we used for the SEMs

File: “Abundance Split and Stand for Effort” is for the Diet Breadth portion

 

Specific information for: **“StandPlantsRawBirds.xlsx”**

Reserve = Reserve number corresponding with a fragment at the Biological Dynamics of Forest Fragments Project (BDFFP).

Time.point = Time since isolation of the reserve. One to two years before the BDFFP’s initial forest fragmentation event (time point = 0), up to four years after the initial fragment isolation (time point = 1), and the most recent datapoint in the 2010s (time point = 2). 

Habitat.size = The size of the forest fragment in hectares. 

Habitat.type = a number for analysis that corresponds with a fragment size. Type 1 = 1 ha, type 2 = 10 ha, type 3 = 100 ha, and type 4 = primary forest. Primary forest represents forest that ha...