Pollinator diversity and density measures: survey and indexing standard to model, detect, and assess pollinator deficits

Abstract

In response to the need to derive empirical data on the status of pollinators, we have developed a protocol to assess the pollinator population in managed and natural ecosystems, especially in Asia where there is no harmonized initiative for pollination research. This protocol is helpful in assessing organic and non-organic farming since pollinator persistence can be an indicator of good and sustainable practices. The three important steps in the protocol are planning, implementation of the survey, and computation of indices. In the planning step, experts rank and classify the pollinator hotspots in various ecosystem types based on the seasonality and likelihood of having high number of flowers and pollinators. Two-stage sampling and mapping of each hotspots are designed. The number of sample hotspots is computed according to sampling precision and confidence levels assigned per class per ecosystem type. In each sample hotspot, sample survey sites are randomly selected according to the agreed sampling precision and confidence levels. In the second step, for orchard or agroecosystem, a grid map with 100 m2 divisions is surveyed. For natural vegetation, survey sites are randomly selected according to the location of pollinator nesting sites. All sampling surveys are conducted during the blooming period of the plants, with consideration of the peak of anthesis, because this is the period when the pollinators are actively foraging, the pollen viability is high, and the nectar secretion is at its peak. Moreover, a template is created to compute for diversity measures and our proposed pollination matching measures (P-to-P ratio and index).