Use of precise spatial data for describing spatial patterns and plant interactions in a diverse Great Basin shrub community

Abstract

Community-structuring processes continue to be of great interest to plant ecologists, and plant spatial patterns have been linked to processes including disturbance, dispersal, environmental heterogeneity, and plant interactions. Under the assumption that the analysis of the spatial structure of plant communities can help to elucidate the type and importance of the predominant community-structuring processes, many studies have analyzed point pattern data on various plant species. A variety of methods have been devised to acquire point pattern data for individual plants, however, the classic tradeoff between the speed of acquisition and the precision of spatial data has meant that large and precise datasets on plant locations are difficult to obtain. The primary goal of this study was to develop a GPS-based methodology for the rapid collection of precise spatial data on plant locations in a semi-arid shrubland in the Great Basin, USA. The secondary goal was to demonstrate a potential application of this approach by using recently developed univariate and bivariate spatial statistics to test for aggregation within the shrub community, as observed in other semi-arid shrublands. We efficiently mapped 2,358 individuals of five shrub species with a spatial error of B0.02 m, and found strong statistical evidence of fine-scale aggregation (1) independent of species, (2) within species, and (3) between two species pairs. Our approach is useful for rapidly collecting precise point pattern data in plant communities, and has other applications related to population modeling, GIS analysis, and conservation.

Changes in spatial point patterns of pioneer woody plants across a large tropical landslide

“…The aggregated patterns found in subzone El are similar to those observed in other stressful environments such as semi-arid shrublands (Rayburn et al, 2011) and savannas (Schleicher et al, 2011), and high-mountain communities (Fajardo et al, 2008). We also detected an increase in aggregation over the study period, as found by Malkison and Kadmon (2007), and Felinks and Wiegand (2008) in early successional communities.…”

Individual species–area relationships and spatial patterns of species diversity in a Great Basin, semi‐arid shrubland

“…Krascheninnikovia lanata showed a non constant intensity within the study plot with some gaps in its distribution (Fig. 1; Rayburn et al 2011), but the detection of the accumulator effect under the heterogeneous null model suggests that habitat association contributes only weakly to the local accumulation of species richness in K. lanata neighborhoods. Repeating the same analyses without considering the focal species in the calculation of the ISAR curve revealed no significant departures from the null model (Table 1; Supplementary material Appendix 1).…”

“… Map of study plot (39 × 39 m), showing locations of all shrub individuals (upper left) and maps detailing the locations of individuals from each of the five shrub species. Figure adapted from Rayburn et al (2011). …”

“…Because not all shrub patterns in the study community were homogeneous (Fig. 1; Rayburn et al 2011), heterogeneous null models were required to approximately separate first and second‐order effects. With a homogeneous Poisson null model (complete spatial randomness or CSR; Wiegand and Moloney 2004) each location in a study plot would have the same chance to receive a relocated individual.…”

Point Pattern Analysis of Different Life Stages of Haloxylon ammodendron in Desert-oasis Ecotone

“…Likewise, this issue is especially relevant and common in semi and semi-arid shrub lands [11,21,22]. Aggregated plant patterns in semiarid shrub lands have been variously attributed to facilitation [21,23,24], habitat heterogeneity [25], disturbance [26] and localized seed dispersal [27].…”