Reproductive phenology of Passiflora cincinnata Mast. in the semi-arid region of Bahia State, Brazil, based on herbarium data and IDW interpolation

Abstract

We investigated intensity and seasonality of the reproductive phenology of Passiflora cincinnata Mast. and estimated its flowering and fruiting periods by interpolation using Inverse Distance Weighting, for the first time in phenology, based on herbarium collections from Bahia State, Northeastern Brazil. Data from 249 exsiccates with flowers and/or fruits were analyzed to estimate the amplitude of flowering and fruiting and test the seasonality using the circular statistics. Passiflora cincinnata flowering and fruiting was greatest from October to May. The maps generated by interpolation showed greatest probability of flowering and fruiting between March and May in sites with mean annual rainfall rates between 500 and 1000 mm. Our results indicated seasonality of flowering and fruiting, with reduced intensities during the austral winter. The interpolation methodology can be used in a complementary or preliminary way, either to organize field visits and set up experiments, or to extrapolate field results for larger-scale views.

When Are Cacti Found with Flowers and Fruits? Estimation of the Reproductive Phenology of the Genus Xiquexique Based on Herbarium Data

“…We used geospatial interpolation inverse distance weighting (IDW) [28] to estimate reproductive phenologies from herbarium collections, according to [7]. The IDW system is a rapid method with low operating costs, characterized as a smoothing and accurate global-type interpolator that is reasonably faithful to the sample data and has high processing speed (QGIS.org 2021).…”

“…The P coefficient, an attribute that determines the power by which the distance between points is increased, was kept by default with a value of 2 (square of the distance) and, after processing, a simple false-color band was applied. Finally, resampling was performed using the bilinear method to remove the knurling effect from the image and produce a map with smooth gradients between values [7].…”

“…(3) the examination of additional notes on the exsiccates; (4) the collection location; (5) the herbarium in which they were deposited; (6) the collection date; and (7) the exclusion of all duplicates or exsiccates containing only vegetative material or without any information concerning reproductive aspects (Figure 4). mation concerning their respective reproductive phenophases.…”

“…Herbarium collections can play a fundamental role in phenological studies in a changing world [2,3], as they contain valuable data concerning reproductive phenology studies that can enable analyses of temporal variations of flowering, fruiting, and seed dispersal cycles [2,3,7]. Such information can play a vital role in understanding the impacts of climate change on plant biology and provide important information for conservation planning and plant resource management strategies in different environments and vegetation formations [2][3][4][5]7].…”

“…Geospatial data tools, such as spatial interpolation, can be used to estimate the properties of unsampled sites based on observed data values at known sites [9]. Among the various methods available, inverse distance weighting (IDW) can be an efficient tool for estimating reproductive phenology and for complementing field data with herbarium information [7].…”