In mixed-jurisdiction landscapes of the Intermountain West, unprotected wildlands in private and State Trust ownership buffer protected areas, support ecosystem and watershed processes, and maintain landscape connectivity, while their subdivision and development, results in losses of habitat and biodiversity, fragmentation, and isolation of neighboring protected areas. In recent decades, conservation easements (CEs) have emerged as the primary tool for protecting private lands, but as private agreements, there is no explicit expectation that land protected provides these conservation values. With this dependence on CEs, identifying their conservation outcomes is critical to understanding their role in landscape-scale conservation efforts. Focusing on the Madrean Archipelago in Arizona and New Mexico, I conducted a mixed methods study assessing the spatial pattern of existing CEs relative to grasslands, riparian areas, and distance from protected areas, and completed stakeholder interviews to identify any process underlying these spatial patterns. Results show that more than 10% of private wildlands in the region are in CEs. They exhibited a strong affinity towards grasslands (almost 20% of private grassland area is in CEs) and protected areas (more than 80% of CEs lie within 1 km of a protected area) but tend to avoid riparian areas. Interviews revealed a moderate level of consistency between the spatial patterns identified and stakeholder objectives. These results suggest that CEs in the Madrean Archipelago do support landscape-scale conservation outcomes, in part because stakeholders engaged in establishing them are prioritizing resources and values with landscape-scale significance. They also affirm the need for more access to spatial data on CEs to better integrate them into regional conservation planning efforts.

Soil water content (SWC) measurements are crucial worldwide for hydrological predictions, agricultural activities, and monitoring the progress of reclamation on disturbed land from industrial activities. In colder climates, snow water equivalent (SWE) measurements are equally important, and directly contribute to improved spring water supply forecasting. Both these variables, SWC and SWE, are commonly measured with either point-scale (e.g. soil cores for SWC and snow tubes for SWE) or large-scale (remote sensing) methods. The cosmic-ray soil moisture probe (CRP) was recently developed to fill this gap between small- and large-scale measurements. The CRP provides an average SWC reading in a landscape-scale measurement footprint (300 m radius) by taking advantage of the relationship between aboveground neutrons and soil water. Although the CRP has proved accurate in relatively homogenous sites, it has not been validated at highly heterogeneous sites. Since snow is simply frozen water, the CRP also has the potential for monitoring SWE at the landscape-scale. However, no calibration has been developed for measuring SWE with the CRP. This thesis aimed to further validate the use of a CRP for measuring SWC at a highly heterogeneous site, and calibrate a CRP for monitoring landscape-scale SWE at an agriculture field. The heterogeneous site used to validate the CRP for SWC measurement was an oil sand reclamation site made up of multiple test plots of varying soil layer treatments. Despite the clear differences in soil texture at the site, the CRP-monitored SWC compared accurately to sampled soil water content and a network of soil moisture probes. With the use of modeling, it was also possible to downscale the CRP measurement to the plot scale. For calibrating the CRP for monitoring SWE, an empirical calibration function was developed based on the relationship between the CRP-measured neutrons and SWE from snow surveys with snow tubes. Using the calibration equation, CRP-estimated SWE closely matched SWE measured from snow surveys. Differences were attributed to mid winter and spring melting of the snowpack along with varying soil water content in the top of the soil profile. This research demonstrates the usefulness of the CRP for monitoring SWC at unique sites and its ability to monitor SWE at the landscape-scale.

Nitrogen (N) fluxes show a substantial variability at the landscape scale. Emissions are transferred by atmospheric, hydrological and anthropogenic dispersion between different landscape elements or ecosystems, e.g. farms, fields, forests or moorland. These landscape N fluxes can cause impacts to the environment, such as loss of biodiversity. The aim of this study is to illustrate how landscape N fluxes can be quantified by integrating atmospheric and fluvial fluxes in a Scottish landscape of 6 km x 6 km that contains intensively managed poultry farming, extensively managed beef and sheep farming, semi-natural moorland and woodland. Atmospheric ammonia (NH3) emissions of two deep pit free range layer poultry houses were estimated by high time-resolution measurements of NH3 concentrations and meteorological variables downwind of layer poultry houses and the application of an inverse Gaussian plume model. Atmospheric NH3 concentrations and deposition fluxes across the study landscape were studied at a resolution of 25 m x 25 m. The approach combined a detailed landscape inventory of all farm activities providing high resolution NH3 emission estimates for atmospheric dispersion modelling and an intensive measurement programme of spatial NH3 concentrations for verifying modelled NH3 concentrations. The spatially diverse emission pattern resulted in a high spatial variability of modelled mean annual NH3 concentrations (0.3 to 77.9 μg NH3 m-3) and dry deposition fluxes (0.1 to >100 kg NH3-N ha-1 yr-1) within the landscape. Annual downstream fluxes and variation in spatial concentration of dissolved inorganic nitrogen (NH4 + and NO3 -) and dissolved organic nitrogen (DON) were studied in the two main catchments within the study landscape (agricultural grassland vs. semi-natural moorland catchment). The grassland catchment was associated with an annual downstream total dissolved nitrogen (TDN) flux of 14.4 kg N ha-1 yr-1, which was 66% higher than the flux of 8.7 kg ha-1 yr-1 from the moorland catchment. This difference was largely due to the NO3 - flux being one order of magnitude higher in the grassland catchment. The contribution of DON to the TDN flux varied between the catchments with 49% in the grassland and 81% in the moorland catchment. Fluvial and atmospheric N fluxes were combined to derive N budgets of the two catchments. Agricultural activities accounted for the majority of N input to the catchments, with atmospheric deposition also playing a significant role, especially in the moorland catchment. Both catchments showed large stream export fluxes compared to their net import which suggests that their capacity of N storage is limited. This thesis quantifies major N fluxes in a study landscape and shows their large spatial variability. Agricultural activities dominate landscape N dynamics. The work demonstrates the importance of considering landscape N variability when attempting to reduce the environmental impact of agricultural activities.

Negative impacts from intensifying agriculture have generated concerns that pollinator-dependent crop species, such as courgette Cucurbita pepo L., may be experiencing a pollination deficit. This thesis explores the extent to which pollination influences fruit set; how pollination could be improved; and how in doing so growers’ profits and agricultural resilience could increase, using UK field-grown courgettes as a model system. Inspired by evidence of parthenocarpy (fruit set in the absence of fertilisation) in courgette, a systematic review showed extensive use of parthenocarpy to circumvent the need for pollination in other ‘pollinator-dependent’ crop species across the globe. Nonetheless, pollination significantly increased yield and pollinators were abundant enough to fulfil the pollination requirements of courgette, which if extrapolated to the rest of the UK, equates to pollinators contributing approximately £2.7 million to annual UK courgette production. Furthermore, wild flowers within fields were shown to be effective at increasing the abundance of bumblebees and solitary bees. Further exploration of the mutualistic relationship between courgettes and pollinators showed that courgette can improve populations of Bombus terrestris (using the Bumble-BEEHAVE model), an important pollinator of courgette. This thesis concludes that pollination is a vital mechanism for ensuring optimal courgette yields and that whilst pollination levels were maximal at study sites, simple management, such as encouraging wild flowers within courgette fields could help to attract pollinators to courgette flowers and support bees’ nutritional requirements beyond the extensive, yet transient, resource provided by courgette. Understanding a crop’s requirement for pollinators can also aid growers in their decision making about what varieties and sites should be used which could increase their agricultural resilience and further their economic advantage. Further work is needed to understand how other environmental factors interact with pollination to influence fruit set so that growers can prioritise key regulating services in their management for optimal crop yields.

Floodplains are amongst the most productive and biodiverse ecosystems. The structure and functioning of floodplains is controlled by the interaction of intermittent inundation with the floodplain landscape. These interactions create highly complex and dynamic ecosystems that are difficult to study at large scales. Consequently, most research of floodplains has been conducted at small spatial and temporal scales. Inundation of floodplains can extend over many square kilometres, however, which unifies the floodplain landscape into an integrated ecosystem operating at the landscape scale. The lack of data and poor understanding of the landscape-scale structure and functioning of floodplains limits the possibility of managing floodplains sustainably as pressure for exploitation of their resources increases. This thesis quantifies the landscape-scale relationship between the frequency and patterns of inundation, the composition and structure of the landscape, and the functioning of the floodplain landscape in terms of the distribution and dynamics of plant growth vigour over an area of approximately 376,000 ha on the Lower Balonne Floodplain; highly biodiverse, semi-arid floodplain ecosystem that straddles the state border between New South Wales and Queensland approximately 500 km inland from the eastern coast of Australia. Mean annual rainfall at St.George, to the north of the study area, is approximately 400�450 mm per year, and median annual evaporation is approximately 2000 mm per year. Plants and animals on the floodplain are therefore heavily dependent upon flooding for survival. This project is based on the analysis of 13 Landsat Thematic Mapper satellite images captured over a 10-year period during which land and water resource development increased substantially. There is now concern that development activities have affected the functioning of the floodplain to the detriment of the natural environment and agricultural productivity. The impacts from these activities on the functioning of the floodplain are not yet known, however. Inundation of the Lower Balonne Floodplain was mapped using a two-part process involving a band ratio to identify deep clear water, and a change detection analysis to identify areas of shallower inundation. This analysis shows that, in contrast with most floodplains, the main flowpath of the Lower Balonne Floodplain runs along its central axis away from river channels, which flow along the floodplain�s outer edges. Inundation propagates from the centre of the floodplain out towards river channels as flood discharge volumes increase. Variations in the spatial pattern of inundated patches within the inundated extent create distinctive aquatic habitat and connectivity conditions at different flow levels. These can be described in terms of three connectivity phases: (I) Disconnected, in which isolated patches of inundation occur at low flows and river channels are hydrologically dislocated from the floodplain; (II) Interaction, where increased hydrological connectivity between inundated patches, and between the floodplain and the river channels at moderate flows, may enable significant exchange of materials, organisms and energy; and (III) Integration, in which almost the entire floodplain landscape is connected by open water during large magnitude floods. There is an abrupt transition in inundation patterns as flows increase between 60,000 ML day-1 and 65,000 ML day-1 (ARI 2 to 2.3 years) in which inundation patterns transform from being relatively disconnected into a highly integrated network of patches. These patterns may have significant consequences for the structure and functioning of the floodplain. Increases in flows across this small range may therefore mark an important ecological flow threshold on this system. Water resource development impacts have changed the relative frequency of flows on the Lower Balonne Floodplain, which will probably affect the sequence of connectivity phases over time. The most likely impact of these changes will be to create a floodplain that is drier overall than under natural flow conditions, and that has a smaller and wetter area of high inundation frequency. The relationship between inundation and the structure of the floodplain landscape was examined by comparing a landcover map showing the distribution and character of 10 landcover types to the inundation frequency maps. Landcover types were mapped from a multi-date Reference Image composite of seven images captured over a period of 10 years. The Reference Image improves landcover discrimination by at least 14% over classification of a single-date image, and has an overall accuracy between 82.5% and 85% at the landscape-scale. The Reference Image shows that the landscape of the Lower Balonne Floodplain is a highly fragmented mosaic of diverse landcover types distributed in association with inundation frequency. Stratifying the floodplain into zones of frequent and rare inundation shows that frequently inundated areas have a less fragmented but less diverse landscape structure than rarely inundated areas. Assessment of the functioning of each landcover types within the floodplain ecosystem, based on landscape pattern metric analysis, indicates that the function of landcover types also changes between inundation frequency zones. Most importantly, these changes include a transformation of the matrix landcover type, which controls the character and dynamics of the ecosystem overall, from Open Grassland to Coolibah Open Woodland in the frequently inundated zone. The landscape structure of the Lower Balonne Floodplain has been affected by development impacts, which include clearing of native vegetation, isolation of parts of the floodplain from natural inundation events by the construction of levee banks and drainage channels, and grazing impacts. Changes to the inundation regime may also affect the structure of the floodplain landscape. Over the long term, these changes are likely to create a larger area of Open Grassland and a smaller area of Coolibah Open Woodland as the zone of frequent inundation becomes smaller and wetter. To examine the functioning of the floodplain ecosystem, the inundation maps were compared to remotely sensed indexes of plant growth vigour at the landscape and landcover-type scales. The dynamics of plant growth vigour over time are influenced by factors operating at the regional, landscape and patch scales. Evaporation is the major control of growth vigour levels at the landscape scale, but each landcover type has a distinctive pattern of growth vigour dynamics that is related to its composition and location, and possibly its landscape structure. The association between the spatial distribution of plant growth vigour and inundation frequency is non-linear, with the highest growth vigour occurring where inundation occurs approximately once per year. This indicates a subsidy-stress interaction with water in which plant growth vigour is limited by soil anoxia in areas of frequent or long term inundation, and by drought stress in rarely inundated areas. A landscape-scale model of growth vigour dynamics, founded on the principles of Hierarchical Patch Dynamics and Landscape Ecology, was created from growth vigour measurements of each landcover type over time. This model was used to examine possible impacts of development activities on the functioning of the floodplain ecosystem. This model shows that the response of plant growth vigour development activities can be complex and subtle, and include a change in mean long-term growth vigour and an increased susceptibility to drought. The model also indicates that periods of high growth vigour can occur in substantially altered floodplain ecosystems. The model was also used to explore the levels of landcover change that might cause a threshold change in the functioning of the ecosystem, which may substantially alter the disturbance-response characteristics of the floodplain ecosystem. The model indicates a threshold change when the extent of Open Grassland is reduced by 30% of its extent in 1993, in which plant growth vigour response to disturbance is virtually inverted from that observed in the images. The temporal variability of plant growth vigour levels increases as the extent of Open Grassland is further reduced. This thesis makes a number of important contributions to our understanding of floodplain structure and functioning. It includes the development of new techniques suited to studying large diverse and complex landscapes at the landscape scale from satellite images, and provides quantitative data describing the links between the structure of floodplain landscapes and their functioning at the landscape scale. This work improves the understanding of floodplain ecosystems by integrating models of floodplain structure and functioning, which have been developed largely from smaller-scale studies of temperate and tropical floodplains, with landscape-scale measurements of this semi-arid system. This thesis also has implications for the Lower Balonne Floodplain by improving the level of information about this important ecosystem and providing baseline data against which the condition of the floodplain can be assessed in future.

To determine possible causes of declining Rio Grande wild turkey (RGWT; Meleagris gallopavo intermedia) abundance in the southern Edwards Plateau, research was conducted on 4 sites, 2 with stable (S [SA and SB]; Kerr and Real counties) and 2 with declining (D [DA and DB]; Bandera County) RGWT populations. RGWTs were trapped, radio-tagged, and tracked. Ranges were constructed with 95% kernels. Data on brood survival and invertebrate and predator abundances were combined with range characteristics to assess habitat at a landscape scale. Annual range sizes did not differ in year 1, but were larger in S than in D in year 2. Range sizes in S increased from year 1 to year 2 while there was no change in range sizes in D. Range overlap was higher in D than S in both years. Movement distances remained consistent in S for both years, but were larger in D during year 1. During year 1 and year 2, RGWT females exhibited larger reproductive ranges and less range overlap in S. Invertebrate abundance for 4 insect orders was 2.5–15.9 times greater in S than in D while coyote abundance was 2–3 times greater in D than in S. Results were similar in year 3, with the exception of SB, where reproductive ranges and spatial arrangement were smaller than all other sites. My results refute the conventional assumption that larger ranges are indicative of poorer habitat quality. Range overlap suggests that useable space may have been limiting in D in the less productive year 2. In D, multiple broods used the same reproductive range, presumably depleting resources faster than in S. Greater predator abundance in D increased the risk of brood predation. The smaller reproductive spatial arrangement of SB females in year 3 correlates there being >3 times the percentage of females missing in other sites. If SB females moved further in year 3 than the detection distance of the radio telemetry equipment, the results would fit the pattern of greater dispersion distance in SA. RGWT females may attempt to separate themselves from other breeding females, possibly to avoid nest or brood predation and/or potential competition for brood resources.

To determine possible causes of declining Rio Grande wild turkey (RGWT; Meleagris gallopavo intermedia) abundance in the southern Edwards Plateau, research was conducted on 4 sites, 2 with stable (S [SA and SB]; Kerr and Real counties) and 2 with declining (D [DA and DB]; Bandera County) RGWT populations. RGWTs were trapped, radio-tagged, and tracked. Ranges were constructed with 95% kernels. Data on brood survival and invertebrate and predator abundances were combined with range characteristics to assess habitat at a landscape scale. Annual range sizes did not differ in year 1, but were larger in S than in D in year 2. Range sizes in S increased from year 1 to year 2 while there was no change in range sizes in D. Range overlap was higher in D than S in both years. Movement distances remained consistent in S for both years, but were larger in D during year 1. During year 1 and year 2, RGWT females exhibited larger reproductive ranges and less range overlap in S. Invertebrate abundance for 4 insect orders was 2.5–15.9 times greater in S than in D while coyote abundance was 2–3 times greater in D than in S. Results were similar in year 3, with the exception of SB, where reproductive ranges and spatial arrangement were smaller than all other sites. My results refute the conventional assumption that larger ranges are indicative of poorer habitat quality. Range overlap suggests that useable space may have been limiting in D in the less productive year 2. In D, multiple broods used the same reproductive range, presumably depleting resources faster than in S. Greater predator abundance in D increased the risk of brood predation. The smaller reproductive spatial arrangement of SB females in year 3 correlates there being >3 times the percentage of females missing in other sites. If SB females moved further in year 3 than the detection distance of the radio telemetry equipment, the results would fit the pattern of greater dispersion distance in SA. RGWT females may attempt to separate themselves from other breeding females, possibly to avoid nest or brood predation and/or potential competition for brood resources.

With the increasing degradation of rivers worldwide, an understanding of spatial and temporal patterns in freshwater quality is important. Water quality is highly variable in space and time, yet this is largely overlooked at the scale of stream catchments. I employed a landscape ecology approach to examine the spatial patterning of water quality in complex, impacted stream networks on the Canterbury Plains of the South Island of New Zealand, with the goal of understanding how land-use effects proliferate through stream systems. In particular, I used “snapshot” sampling events in conjunction with spatial modelling and longitudinal profiles to investigate the ways in which spatial and environmental factors influence the variability of water quality in stream networks. Spatial eigenfunction analyses showed that distance measures, which took into account variable connectivity by flow and distance along the stream between sites, explained more spatial variance in water quality than traditional distance metrics. Small upstream reaches were more spatially and temporally variable than main stems (under summer base-flow conditions). The extent of spatial variation in water quality differed between stream networks, potentially depending on linkages to groundwater and the surrounding landscape. My results indicated that the water quality of headwater streams can have a disproportionate influence over water quality throughout an entire network. I investigated spatio-temporal patterns in water quality more intensively in one stream network, the Cam River, in which I found consistent spatial pattern through time. The relative balance between nutrient inputs (pollution and groundwater) and in-stream conditions influenced the spatial pattern of water quality, as well as that of several ecosystem processes which I measured simultaneously. The spatially intensive and explicit approach has allowed identification of key factors controlling water quality and ecosystem processes throughout the Cam River. This research highlights the importance of taking a spatially explicit approach when studying stream water quality and that such an approach could be insightful and will contribute to solving current stream management problems.

This research demonstrates the ability to integrate a computer simulation model with a geographic information system (GIS) to predict forest community dynamics in both the spatial and temporal dimensions. A landscape scale computer simulation model, LANDSIM, was coupled with the Arc/Info GIS to simulate the interaction of forest fires and forest succession at Bryce Canyon National Park, Utah, and to produce maps of the predicted community types. The sensitivity of the model was tested with respect to the fire return interval, maximum neighbor spread, and the effect of slope upon the spread of simulated fires. The model predicts that each fire return interval will result in an unique distribution of community types upon the landscape. The model's results are discussed in terms of their implications for management alternatives at Bryce Canyon National Park.

No description available.