Integrating paper-based habitat mapping with mobile electronic field recording procedures

Abstract

A hybrid method of ecological habitat survey and mapping is presented, bridging paper-based methods and mobile electronic procedures. The hybrid approach uses a hand-held PDA with real-time dGPS to map habitats and record habitat attributes. It retains paper field maps to facilitate ecological decisions and to overcome the need for field surveyors to operate a fully functional mobile GIS system. The transition from paper records to a full GIS implementation is bridged by secondary digitisation in which a GIS specialist, trained in field survey procedures, interacts routinely with the field surveyors, throughout the field season to assure data quality standards. The methodology is practical and affordable, particularly if there are multiple field surveyors.

Introduction

Electronic field data capture has become widely adopted in recent years as a result of advances in computer technology. Handheld computers or personal digital assistants (PDAs) are now integral to data recording and data management in the field. Electronic field data capture has proved to be an effective alternative to paper-based modes of data recording because it is more efficient and less open to transposition error when converted to digital format for analysis. In disciplines such as medicine it is preferred by most users (Lane et al., 2006) and within education PDAs have been shown to be effective in a co-operative learning environment (Lai and Wui, 2006). PDAs have been used in arboriculture to record tree species distribution and management (Tait et al., 2009) and in agriculture to map crop distribution (Wagtendonk et al., 2004). Field biologists sampling crab (Paralithodes camtschaticus) populations (Van Tamelen, 2004) found data collection and transfer to computer to be three times faster using electronic data capture compared to handwritten methods. The greater rate of data capture can provide opportunity for increased sampling intensity or free up time for error checking and data analysis (Wagtendonk and De Jeu, 2007).

Advances in mobile electronic data capture by PDAs have reduced the constraints of bulky, expensive PC tablets. Operating systems such as Windows Mobile (Microsoft, 2002) and the development of mobile GIS software such as ArcPad (ESRI, 2009), Fastmap (Trimble, 2006a) and Mobile GRASS (Stankovic et al., 2004) have been introduced so that PDAs can now compete with GIS desktop computing power. GPS has also become more reliable and accurate over recent years, with some handheld differential GPS devices now capable of producing sub-metre accuracy in real time.

Within the context of biodiversity field recording software, Jones et al. (2007) showed that customised user graphic-interface techniques (electronic data entry forms) provide efficient data entry applications for ecological field studies. Cybertracker (Cybertracker, 2009) has also developed as a field data recording tool, particularly for recording animal wildlife sightings (Travaini et al., 2007). It has a graphic icon-based user interface that facilitates data entry without having to write words (Liebenberg, 2003). Likewise EcoPod has been developed to replace printed paper field-guides to increase the efficiency of identifying and recording plant and animal species in the field (Yu et al., 2006).

The permanence, low cost, ease of use and flexibility of data formats such as structured recording sheets, target notes and sketch maps offered by waterproof paper recording are extensively used by ecologists. As a consequence ButterflyNet was developed to produce a mobile electronic data collection system capable of supporting this range of data formats (Yeh et al., 2006).

Practical electronic recording methods that address the multivariate structure and the spatial and temporal distribution patterns that characterise terrestrial vegetation continue to present a challenge. Typically, habitat mapping is associated with recording habitat attributes such as plant species composition, vegetation structure and management. A major decision when selecting GIS habitat mapping methodologies is whether to incorporate real-time primary digitising in the field or secondary digitising as a post-field work task (McCaffrey et al., 2005). While the primary digitising of ecological (Maskell et al., 2008) and geological (Clegg et al., 2006) field mapping with PC tablets is feasible, a review of twenty-nine European geological organisations found that only two used primary digital data capture in the field (Jackson and Asch, 2002). Athey et al. (2008) found that field geologists were reluctant to embrace PC tablets and mapping in the field as they were fearful that they would damage hardware and did not find data entry user friendly.

While there is consensus on the potential value of mobile computing, the transition from paper to digital methods can be problematic (Wagtendonk and De Jeu, 2007). Our paper outlines an electronic, field-based approach to habitat mapping that optimises the simplicity and security of paper records, the efficiency of electronic data capture and the accuracy of GPS habitat boundary recording (McCann et al., 2009). We exemplify the approach with a case study in which habitats, habitat boundaries and habitat composition, structure and management were recorded in a sample set of 25 ha sample grid squares across Northern Ireland (Cooper et al., 2009).