A low-altitude mountain range as an important refugium for two narrow endemics in the Southwest Australian Floristic Region biodiversity hotspot.

BACKGROUND AND AIMS: Low-altitude mountains constitute important centres of diversity in landscapes with little topographic variation, such as the Southwest Australian Floristic Region (SWAFR). They also provide unique climatic and edaphic conditions that may allow them to function as refugia. We investigate whether the Porongurups (altitude 655 m) in the SWAFR will provide a refugium for the endemic Ornduffia calthifolia and O. marchantii under forecast climate change. METHODS: We used species distribution modelling based on WorldClim climatic data, 30-m elevation data and a 2-m-resolution LiDAR-derived digital elevation model (DEM) to predict current and future distributions of the Ornduffia species at local and regional scales based on 605 field-based abundance estimates. Future distributions were forecast using RCP2.6 and RCP4.5 projections. To determine whether local edaphic and biotic factors impact these forecasts, we tested whether soil depth and vegetation height were significant predictors of abundance using generalized additive models (GAMs). KEY RESULTS: Species distribution modelling revealed the importance of elevation and topographic variables at the local scale for determining distributions of both species, which also preferred shadier locations and higher slopes. However, O. calthifolia occurred at higher (cooler) elevations with rugged, concave topography, while O. marchantii occurred in disturbed sites at lower locations with less rugged, convex topography. Under future climates both species are likely to severely contract under the milder RCP2.6 projection (approx. 2 °C of global warming), but are unlikely to persist if warming is more severe (RCP4.5). GAMs showed that soil depth and vegetation height are important predictors of O. calthifolia and O. marchantii distributions, respectively. CONCLUSIONS: The Porongurups constitute an important refugium for O. calthifolia and O. marchantii, but limits to this capacity may be reached if global warming exceeds 2 °C. This capacity is moderated at local scales by biotic and edaphic factors.

Spatial structure of seagrass suggests that size-dependent plant traits have a strong influence on the distribution and maintenance of tropical multispecies meadows.

BACKGROUND: Seagrass species in the tropics occur in multispecies meadows. How these meadows are maintained through species co-existence and what their ecological drivers may be has been an overarching question in seagrass biogeography. In this study, we quantify the spatial structure of four co-existing species and infer potential ecological processes from these structures. METHODS AND RESULTS: Species presence/absence data were collected using underwater towed and dropped video cameras in Pulau Tinggi, Malaysia. The geostatistical method, utilizing semivariograms, was used to describe the spatial structure of Halophila spp, Halodule uninervis, Syringodium isoetifolium and Cymodocea serrulata. Species had spatial patterns that were oriented in the along-shore and across-shore directions, nested with larger species in meadow interiors, and consisted of multiple structures that indicate the influence of 2-3 underlying processes. The Linear Model of Coregionalization (LMC) was used to estimate the amount of variance contributing to the presence of a species at specific spatial scales. These distances were <2.5 m (micro-scale), 2.5-50 m (fine-scale) and >50 m (broad-scale) in the along-shore; and <2.5 m (micro-scale), 2.5-140 m (fine-scale) and >140 m (broad-scale) in the across-shore. The LMC suggests that smaller species (Halophila spp and H. uninervis) were most influenced by broad-scale processes such as hydrodynamics and water depth whereas large, localised species (S. isoetifolium and C. serrulata) were more influenced by finer-scale processes such as sediment burial, seagrass colonization and growth, and physical disturbance. CONCLUSION: In this study, we provide evidence that spatial structure is distinct even when species occur in well-mixed multispecies meadows, and we suggest that size-dependent plant traits have a strong influence on the distribution and maintenance of tropical marine plant communities. This study offers a contrast from previous spatial models of seagrasses which have largely focused on monospecific temperate meadows.

The influence of urban design on neighbourhood walking following residential relocation: longitudinal results from the RESIDE study.

The design of urban environments has the potential to enhance the health and well-being of residents by impacting social determinants of health including access to public transport, green space and local amenities. Commencing in 2003, RESIDE is a longitudinal natural experiment examining the impact of urban planning on active living in metropolitan Perth, Western Australia. Participants building homes in new housing developments were surveyed before relocation (n = 1813; 34·6% recruitment rate); and approximately 12 months later (n = 1437). Changes in perceived and objective neighbourhood characteristics associated with walking following relocation were examined, adjusted for changes in demographic, intrapersonal, interpersonal and baseline reasons for residential location choice. Self-reported walking was measured using the Neighbourhood Physical Activity Questionnaire. Following relocation, transport-related walking declined overall (p < 0.001) and recreational walking increased (p < 0.001): access to transport- and recreational destinations changed in similar directions. However, in those with increased access to destinations, transport-related walking increased by 5.8 min/week for each type of transport-related destination that increased (p = 0.045); and recreational walking by 17.6 min/week for each type of recreational destination that increased (p = 0.070). The association between the built environment and recreational walking was partially mediated by changes in perceived neighbourhood attractiveness: when changes in 'enjoyment' and 'attitude' towards local walking were removed from the multivariate model, recreational walking returned to 20.1 min/week (p = 0.040) for each type of recreational destination that increased. This study provides longitudinal evidence that both transport and recreational-walking behaviours respond to changes in the availability and diversity of local transport- and recreational destinations, and demonstrates the potential of local infrastructure to support health-enhancing behaviours. As neighbourhoods evolve, longer-term follow-up is required to fully capture changes that occur, and the impact on residents. The potential for using policies, incentives and infrastructure levies to enable the early introduction of recreational and transport-related facilities into new housing developments warrants further investigation.

Modelling deep water habitats to develop a spatially explicit, fine scale understanding of the distribution of the western rock lobster, Panulirus cygnus.

BACKGROUND: The western rock lobster, Panulirus cygnus, is endemic to Western Australia and supports substantial commercial and recreational fisheries. Due to and its wide distribution and the commercial and recreational importance of the species a key component of managing western rock lobster is understanding the ecological processes and interactions that may influence lobster abundance and distribution. Using terrain analyses and distribution models of substrate and benthic biota, we assess the physical drivers that influence the distribution of lobsters at a key fishery site. METHODS AND FINDINGS: Using data collected from hydroacoustic and towed video surveys, 20 variables (including geophysical, substrate and biota variables) were developed to predict the distributions of substrate type (three classes of reef, rhodoliths and sand) and dominant biota (kelp, sessile invertebrates and macroalgae) within a 40 km(2) area about 30 km off the west Australian coast. Lobster presence/absence data were collected within this area using georeferenced pots. These datasets were used to develop a classification tree model for predicting the distribution of the western rock lobster. Interestingly, kelp and reef were not selected as predictors. Instead, the model selected geophysical and geomorphic scalar variables, which emphasise a mix of terrain within limited distances. The model of lobster presence had an adjusted D(2) of 64 and an 80% correct classification. CONCLUSIONS: Species distribution models indicate that juxtaposition in fine scale terrain is most important to the western rock lobster. While key features like kelp and reef may be important to lobster distribution at a broad scale, it is the fine scale features in terrain that are likely to define its ecological niche. Determining the most appropriate landscape configuration and scale will be essential to refining niche habitats and will aid in selecting appropriate sites for protecting critical lobster habitats.

School site and the potential to walk to school: the impact of street connectivity and traffic exposure in school neighborhoods.

The impact of neighborhood walkability (based on street connectivity and traffic exposure) within 2 km of public primary schools on children regularly walking to school was examined. The most (n=13) and least walkable (n=12) schools were selected using a school-specific 'walkability' index and a cross sectional study undertaken of Year 5, 6 and 7 children (n=1480) and consenting parents (n=1332). After adjustment, regularly walking to school was higher in children attending schools in high walkable neighborhoods (i.e, high street connectivity and low traffic volume) (Odds ratio (OR) 3.63; 95% Confidence Interval (CI) 2.01-6.56), and less likely in neighborhoods with high connectivity but high traffic volume (OR 0.32; 95% CI 0.22-0.47). Connected street networks provide direct routes to school but when designed for heavy traffic, the potential for children to walk to school is reduced. This highlights the importance of carefully considering school siting and, particularly, street design in school neighborhoods.

Associations between intrapersonal and neighborhood environmental characteristics and cycling for transport and recreation in adults: baseline results from the RESIDE study.

BACKGROUND: This study investigated the relationship between individual and neighborhood environmental factors and cycling for transport and for recreation among adults living in Perth, Western Australia. METHODS: Baseline cross-sectional data from 1813 participants (40.5% male; age range 18 to 78 years) in the RESIDential Environment (RESIDE) project were analyzed. The questionnaire included information on cycling behavior and on cycling-specific individual, social environmental, and neighborhood environmental attributes. Cycling for transport and recreation were dichotomized as whether or not individuals cycled in a usual week. RESULTS: Among the individual factors, positive attitudes toward cycling and perceived behavioral control increased the odds of cycling for transport and for recreation. Among the neighborhood environmental attributes, leafy and attractive neighborhoods, access to bicycle/walking paths, the presence of traffic slowing devices and having many 4-way street intersections were positively associated with cycling for transport. Many alternative routes in the local area increased the odds of cycling for recreation. CONCLUSIONS: Effective strategies for increasing cycling (particularly cycling for transport) may include incorporating supportive environments such as creating leafy and attractive neighborhood surroundings, low traffic speed, and increased street connectivity, in addition to campaigns aimed at strengthening positive attitudes and confidence to cycle.

Evaluation of the implementation of a state government community design policy aimed at increasing local walking: design issues and baseline results from RESIDE, Perth Western Australia.

OBJECTIVES: To describe the design and baseline results of an evaluation of the Western Australian government's pedestrian-friendly subdivision design code (Liveable Neighborhood (LN) Guidelines). METHODS: Baseline results (2003-2005) from a longitudinal study of people (n=1813) moving into new housing developments: 18 Liveable, 11 Hybrid and 45 Conventional (i.e., LDs, HDs and CDs respectively) are presented including usual recreational and transport-related walking undertaken within and outside the neighborhood, and 7-day pedometer steps. RESULTS: At baseline, more participants walked for recreation and transport within the neighborhood (52.6%; 36.1% respectively), than outside the neighborhood (17.7%; 13.2% respectively). Notably, only 20% of average total duration of walking (128.4 min/week (SD159.8)) was transport related and within the neighborhood. There were few differences between the groups' demographic, psychosocial and perceived neighborhood environmental characteristics, pedometer steps, or the type, amount and location of self-reported walking (p>0.05). However, asked what factors influenced their choice of housing development, more participants moving into LDs reported aspects of their new neighborhood's walkability as important (p<0.05). CONCLUSIONS: The baseline results underscore the desirability of incorporating behavior and context-specific measures and value of longitudinal designs to enable changes in behavior, attitudes, and urban form to be monitored, while adjusting for baseline residential location preferences.

Accessibility and connectivity in physical activity studies: the impact of missing pedestrian data.

OBJECTIVE: One important characteristic in physical activity research into the built environment is network connectivity, usually calculated using street networks. However, a true pedestrian network may have very different connectivity than a street network. This study, conducted in 2004, examines the difference in walkability analyses when street networks versus pedestrian networks are used for four metropolitan suburbs in Perth, Western Australia. METHODS: A street network of Perth was used to represent the current standard of data for walkability analyses. Aerial photography from 2003 was used to create a pedestrian network, which incorporated pedestrian footpaths into the street network. The street and pedestrian networks were compared using three measures of connectivity: Pedsheds, link node ratio and pedestrian route directness. RESULTS: A comparison of the results using street versus pedestrian networks showed very different outcomes for conventional neighbourhood designs. Connectivity measures for conventional neighbourhoods improved up to 120% with the addition of pedestrian networks, although traditional neighbourhoods still had slightly better connectivity values overall. CONCLUSION: The true pedestrian network increases the connectivity of a neighbourhood and may have significant impact on these measures, especially in neighbourhoods with conventional street designs. It is critical that future studies incorporate pedestrian networks into their analyses.

Predictive vegetation modeling for conservation: impact of error propagation from digital elevation data.

The effect of digital elevation model (DEM) error on environmental variables, and subsequently on predictive habitat models, has not been explored. Based on an error analysis of a DEM, multiple error realizations of the DEM were created and used to develop both direct and indirect environmental variables for input to predictive habitat models. The study explores the effects of DEM error and the resultant uncertainty of results on typical steps in the modeling procedure for prediction of vegetation species presence/absence. Results indicate that all of these steps and results, including the statistical significance of environmental variables, shapes of species response curves in generalized additive models (GAMs), stepwise model selection, coefficients and standard errors for generalized linear models (GLMs), prediction accuracy (Cohen's kappa and AUC), and spatial extent of predictions, were greatly affected by this type of error. Error in the DEM can affect the reliability of interpretations of model results and level of accuracy in predictions, as well as the spatial extent of the predictions. We suggest that the sensitivity of DEM-derived environmental variables to error in the DEM should be considered before including them in the modeling processes.

Development of a reliable measure of walking within and outside the local neighborhood: RESIDE's Neighborhood Physical Activity Questionnaire.

BACKGROUND: The RESIDential Environment project (RESIDE) is a longitudinal study evaluating the impact of a new residential design code on walking. OBJECTIVE: To develop a reliable measure of walking--undertaken within and outside the neighborhood--and overall physical activity. METHODS: A test-retest reliability study was undertaken (n = 82, mean age 39 years). The instrument was based on the International Physical Activity Questionnaire (IPAQ-short version) and Active Australia Survey. It measured usual frequency and duration of (1) recreational- and transport-related walking within and outside the neighborhood and (2) other vigorous and moderate physical activities. RESULTS: Reliability of recall of whether participants had walked within (k = 0.84) and outside (0.73) the neighborhood was acceptable. Similarly, recall of frequency and duration of transport and recreational-related walking within the neighborhood was excellent (ICC > or = 0.82), as was recall of transport-related walking trips outside the neighborhood (ICC > or = 0.84). Reliability for duration of recreational walking outside the neighborhood was fair to good (ICC = 0.55). The reliability of indices of total physical activity based on MET min/week (ICC = 0.82) and MET min/week dichotomized to 'sufficient' physical activity for health (kappa = 0.67) were both acceptable. CONCLUSIONS: The Neighborhood Physical Activity Questionnaire (NPAQ) is sufficiently reliable for studies examining environmental correlates of walking within the neighborhood.