DOI: 10.5061/dryad.bnzs7h4mb
title: Habitat edges decrease plant reproductive output in fragmented landscapes

description: Habitat loss is a major threat to biodiversity, but effects of habitat
 fragmentation are less clear. Examining drivers of key demographic
 processes, such as reproduction, will clarify species-level responses to
 fragmentation and broader effects on biodiversity. Yet, understanding how
 fragmentation affects demography has been challenging due to the many ways
 landscapes are altered by co-occurring habitat loss and fragmentation,
 coupled with the rarity of experiments to disentangle these
 effects.  In a large, replicated fragmentation experiment with
 open savanna habitats surrounded by pine plantation forests, we tested the
 effects of inter-patch connectivity, patch edge-to-area ratio, and
 within-patch distance from an edge on plant reproductive output. Using
 five experimentally planted species of restoration interest – three
 wind-pollinated grass species and two insect-pollinated forb species – we
 measured plant flowering, pollination rate, and seed production. All plant
 species were more likely to flower and produce more flowering structures
 farther from the forest edge. Connectivity and distance from an edge,
 however, had no effect on pollination rate (regardless of pollination
 mode). Despite no influence of fragmentation on pollination, plant seed
 production increased further from the edge for four of five species,
 driven by the increase in flower production. Synthesis: Altogether, we
 demonstrate that plant reproductive output (seed production) is decreased
 by habitat fragmentation through edge effects on flowering. Our work
 provides evidence that an important contributor to plant demography,
 reproductive output, is altered by edge effects in fragmented patches.
 These species-level impacts of fragmentation may provide insight into the
 mechanisms of fragmentation effects on community-level changes in
 biodiversity.
description: # Habitat edges decrease plant reproductive output in fragmented
 landscapes
 [https://doi.org/10.5061/dryad.bnzs7h4mb](https://doi.org/10.5061/dryad.bnzs7h4mb) ## Description of the data and file structure Data collected from experimentally fragmented landscapes at the Savannah River Site. Five plant species were experimentally planted at varying distances from the edge. Reproductive status, flowering, and seed production were recorded for each individual.  ### Files and variables Contact: Katherine Hulting, [hultingk@msu.edu](mailto:hultingk@msu.edu) **File name: archive-SRS-2009-seeds.csv** Each row contains data for one structure on one plant (3 structures/plant). | Variable | Description | | :------------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | block | Site name (block8, block10, block52, block57, block53N, block53S, block54N, or block54S) | | patch | Patch Identifier (A = Center, B = Connected, C = Wing or Rectangle, D = Wing or Rectangle, E = Wing or Rectangle (labeled clock-wise from patch B) | | corner | Corner of patch where plant is located | | distance | Categorical distance of plant from edge. a = 0m from edge, b = 10.25m from edge, c = 19.10m from edge, d = 36.10m from edge | | species | Genus of focal plant species | | stalk | stalk # of observation (1-3 stalks per individual plant) | | no.viable\_seeds | Number of fruits that contained a developed seed, NA = non-reproductive plant or not recorded | | no.nonviable\_seeds | Number of fruits that did not contain a developed seed, NA = non-reproductive plant or not recorded | | dispersed\_percent | Percent of structure that dispersed prior to collection, NA = 0% dispersal | | ptype | Patch type (Center, Connected, Rectangle, Winged) | | live | 0 = dead, 1 = alive, NA = not recorded | | reproductive | 0 = not reproductive, 1 = reproductive, NA = not recorded or dead plant | | length | length of plant measured along long axis (cm), NA = dead plant or not recorded | | width | width of plant perpendicular to length measure (cm) , NA = dead plant or not recorded | | height | height of plant (cm), NA = dead plant or not recorded | | no\_basal\_fl | Number of flowering stalks originating from the plant base, NA = non-reproductive plant or not recorded | | no\_axil\_fl | Number of axilary flowering stalks, NA = non-reproductive plant or species with no axilary flowering stalks (Aristida, Anthaenantia, Sorghastrum) | | predisp\_seedpred | Percent of non viable seeds with signs of pre-dispersal seed predation, NA = non-reproductive plant or not recorded | | flags | Data is flagged for issues. 0 = no issues, 1 = delete pollination or pre-dispersal seed predation data for this plant because it never flowered, 2 = pollination data not recorded, 3 = pollination and seed predation data not recorded, 4 = pollination data recorded but not being used, 5 = number of flowers not recorded, 6 = missing all data.  |