Land-Use References

Year Title (Author, Description) File Download
2011

Ecosystem Service Assessment of Wetland Water Purification for the Shepard Slough Study Area

Irena F. Creed Consulting

There is a critical need for regional scale assessments of wetlands for ecosystem services. This study reports on a regional scale assessment using Geographical Information Systems (GIS) and remote sensing (RS) technologies for water purification services provided by wetlands in Shepard Slough, the study area for the Ecosystem Services Pilot Project (ESPP). Prototypes were developed for both a basic (readily available GIS and RS data, most of it freely downloadable from the Internet) and advanced (higher quality datasets with higher spatial resolution) approach. Due to the severe time constraints of the contract (during which we were unable to gain access to the required data for the advanced approach), only the “Regional-Basic” approach was implemented. Based on this Regional-Basic approach, we found monetary benefits to increase from 1990 to 2010 for water purification, with the monetary increase due mainly to an increase in wetland area defined by inundated water. We expect the “Regional-Advanced” approach to provide a more precise analysis, as the basic approach is based largely on the area of wetlands for water purification and ignores many of the other wetland features important for water purification.

 Contact ALCES for Irena F. Creed Consulting, 2011
2011

Ecosystem Services Approach Pilot on Wetlands Wetland Ecosystem Services Protocol for the United States (WESPUS) Site Assessments

02 Planning + Design Inc.

The Wetland Ecosystem Services Protocol for the United States (WESPUS) was highlighted by Alberta Environment as a method with the potential to help address identified gaps in the current regulatory context surrounding wetlands. This assessment was conducted for Alberta Environment by the Biophysical Team for the Wetland Ecosystem Services Pilot project in the Shepard Slough area east of Calgary, with the work being led and coordinated by O2 Planning + Design Inc. (O2). The intention of the WESPUS component of the pilot study was to identify the potential applicability of WESPUS in the context of Alberta’s biophysical and regulatory landscapes. The purpose of the WESPUS component was to learn more about the WESPUS method, apply it using field assessments across a range of sites within the pilot study area, and to provide recommendations and strategies for moving forward in terms of potentially informing provincial policy and regulatory processes. After a series of trial site assessments and data analysis, the following recommendations and strategies were among those provided:  use caution when making inferences and correlations with Steward and Kantrud wetlands classes, as all classes appear to serve many ecosystem services  compare relative values of ecosystem function with a socio-economic evaluation of wetlands function  identify the differences in effectiveness and values of constructed wetlands based on their designated purpose  potentially use this tool to evaluate whether the pre-disturbance function of the compensated wetland has been effectively replaced post construction  consider how to address wetland numbers vs. wetland area. For example, if eight 1 ha wetlands are disturbed and replaced with one 8 ha wetland, it may not address the replacement of the original wetlands’ function  request that Dr. Paul Adamus make some adjustments to amend the WESPUS tool for the Alberta context and that some references are added to assist the field surveyor  initiate further research projects to strengthen the empirical data for Wetlands Ecosystem Services and to assist regulators in making approval decisions (e.g., conduct trials for boreal peatland applications) The ability of WESPUS to address the gaps and weaknesses in the approval process based on the findings of the site assessments are discussed as well. For example:  WESPUS has the ability to inform what types of functions and related ecosystem services a wetland provides. It can also provide objective information on the values and functions of small and temporary wetlands which are often written off as unimportant when compared to large and visually appealing wetlands with permanent open water zones. This tool can provide some evidence to support avoidance, mitigation and compensation decisions on wetlands.  Applying WESPUS in the context of individual applications for wetland disturbance may improve cumulative effects management over time by moving towards greater maintenance of wetland functions and services as opposed to simply wetland acreage under a no net loss policy. Further investigation is required to determine how to make WESPUS compatible with a cumulative effects management system.  A standardized protocol such as WESPUS does allow for a quantifiable and objective approach in communicating the value of wetlands. An evaluation tool such as WESPUS could be used province-wide to evaluate the function and value of all types of wetlands and help inform reclamation planning or compensation efforts.

 Contact ALCES for 02 Planning + Design Inc., 2011
2011

Defining Pre-Industrial and Current Disturbance Regime Parameters for the North Saskatchewan Regional Planning Area

David Andison

This report is a technical and scientific support document to the land use planning process for the North Saskatchewan Regional Plan landscape. More specifically, the information here will provide the best available state-of-knowledge of the pre-industrial and current or business-as-usual disturbance regimes. Furthermore, this information will be used as input for a scenario / simulation modelling exercise. Specifically the Objective is: To provide a complete and succinct summary of the current state of knowledge of all key parameters of the historic and current disturbance regimes of the North Saskatchewan landscape in a model-user-friendly format.

 Contact ALCES for David Andison, 2011
2011

Guidelines for Using the IUCN Red List Categories and Criteria

The Standards and Petitions Subcommittee of the IUCN Species Survival Commission

The IUCN Red List Categories and Criteria were first published in 1994 following six years of research and broad consultation (IUCN 1994). The 1994 IUCN Categories and Criteria were developed to improve objectivity and transparency in assessing the conservation status of species, and therefore to improve consistency and understanding among users. The 1994 categories and criteria were applied to a large number of species in compiling the 1996 Red List of Threatened Animals. The assessment of many species for the 1996 Red List drew attention to certain areas of difficulty, which led IUCN to initiate a review of the 1994 categories and criteria, which was undertaken during 1998 to 1999. This review was completed and the IUCN Red List Categories and Criteria (version 3.1) are now published (IUCN 2001). This document provides guidelines to the application of version 3.1 of the categories and criteria, and in so doing addresses many of the issues raised in the process of reviewing the 1994 categories and criteria. This document explains how the criteria should be applied to determine whether a taxon belongs in a category of threat, and gives examples from different taxonomic groups to illustrate the application of the criteria. These guidelines also provide detailed explanations of the definitions of the many terms used in the criteria. The guidelines should be used in conjunction with the official IUCN Red List Categories and Criteria booklet (IUCN 2001).

 Contact ALCES for The Standards and Petitions Subcommittee of the IUCN Species Survival Commission, 2011
2011

Chief Mountain Cumulative Effects Study

Barry Wilson and Mark Hudson

The Chief Mountain Study attempts to balance the perspectives of different stakeholders in the area and is based on the premise that all land uses examined provide economic benefits, but these benefits may have associated environmental liabilities, such as impacts on surface and groundwater or the loss of natural biodiversity. It also recognizes some liabilities may be minor by themselves, but have more serious cumulative effects. The study attempts to identify potentially conflicting land use trends and to show that even the decisions of individuals can have beneficial or negative consequences.

 Contact ALCES for Barry Wilson and Mark Hudson, 2011
2011

The Challenge of Developing Social Indicators for Cumulative Effects Assessment and Land Use Planning

Mitchell, R. E., and J. R. Parkins

This paper provides a synopsis on social indicators as relevant to cumulative effects assessment and land use planning. Although much has been done to better understand the social dimensions of environmental assessment, empirical work has been lacking on social indicators that could be used either as measurable inputs or outputs for cumulative effects assessment and land use planning in different kinds of communities and regions. Cumulative effects models currently in practice often fail to address deeper issues of community and regional well-being. Against this gap, social scientists are being asked to make reliable generalizations about functional, measurable relationships between certain social indicators and land use change or scenarios. To address this challenge, the Alberta Research Council held a two-day workshop in 2005 with social scientists. The workshop resulted in a list of prioritized social indicators that could be included in cumulative effects modeling/assessments and land use planning. The top five social indicators included population growth rate, education attainment, self-assessed quality of life, equity, i.e., distribution of benefits, and locus of control. Although consensus on social indicators and social thresholds for cumulative effects models was not reached, the insight gained from the workshop will help inform future cumulative effects assessment and land use planning.

 Contact ALCES for Mitchell, R. E., and J. R. Parkins, 2011
2011

Deliberative Democracy, Institution Building, and the Pragmatics of Cumulative Effects Assessment

Parkins, J. R.

Cumulative effects assessment is a process of scientific analysis, social choice, and public policy development, yet the linkages among these domains are often less than transparent. Limits to scientific and technical assessment, issues of power and control of information, and episodic forms of civic engagement represent serious challenges to meaningful understanding of cumulative effects assessment and land-use planning. In articulating these challenges, I draw on case studies from Ontario's Lands for Life and Alberta's Land-use Framework to illustrate current limitations to cumulative effects assessment on public lands in Canada. As a partial remedy for these limitations, insights into a pragmatic approach to impact assessment, in contrast to decisionistic and technocratic approaches, offer a way forward through a more robust integration of scientific information, civic engagement, and public policy development. I also identify a need for longer-standing institutions that are dedicated to regional planning and cumulative effects assessment in Canada.

 Contact ALCES for Parkins, J. R., 2011
2011

Scenario Analysis to Identify Viable Conservation Strategies in Paraguay’s Imperiled Atlantic Forest

Carlson, M. J., R. Mitchell, and L. Rodriguez

A common challenge facing land use planning is assessment of the future performance of land use options. The challenge can be acute in developing regions where land use is expanding rapidly and funding and data needed for planning are scarce. To inform land use planning for a biosphere reserve located in Paraguay’s Atlantic forest region, a scenario analysis explored the relative merits of conventional and conservation agricultural practices, sustained yield forestry, and protection. Simulations compared the long-term impacts on land cover, biotic carbon, and income of the area’s residents. Ecological and economic decline were projected under conventional practices. Protection and forestry scenarios achieved only small relative improvements to ecological indicators at the cost of reduced economic performance. By addressing the underlying issue of land degradation, conservation agriculture including no-tillage was the most successful land use strategy both ecologically and economically. Identification of conservation agriculture as the most promising land use strategy prioritizes issues that must be addressed to achieve sustainability, most importantly the provision of education and funding to smallholder farmers. We conclude that scenario analysis offers a flexible strategy to integrate available data for the purpose of informing land use planning in data-limited regions such as Paraguay’s Atlantic forest.

 Contact ALCES for Carlson, M. J., R. Mitchell, and L. Rodriguez, 2011
2011

Synthesis of Habitat Models used in the Oil Sands Region

Judy E. Muir, M.Sc., R.P.Bio. Virgil C. Hawkes, M.Sc., R.P.Bio., Krysia N. Tuttle, M.Sc. and Tony Mo

This project assessed the current state of habitat models used in oil sands region EIA and closure planning to meet the following objectives: 1. Determine which habitat models are used in EIAs and closure planning, and how these models were used; 2. Determine what linkages exist between the habitat model predictions in the EIAs and closure plans; 3. Determine which habitat models have been validated, and of these, describe and evaluate the validation procedures that were used on each model with recommendations for improvement if needed; and 4. Recommend procedures to validate non-validated models. These four objectives were addressed through the completion of four tasks: 1. Review and summarize EIA species habitat models used in the oil sands regions for Environmental Impact Assessments (EIAs) for oil sands project applications and for other projects such as wildlife habitat mapping. 2. Review and summarize how regional wildlife habitat mapping data, EIA habitat model data, and habitat models, are used to develop oil sands closure plans conducted by SEWG or for the Lower Athabasca Regional Plan (LARP) 3. Summarize the validation methods and status of existing validated models 4. Provide recommendations for validation procedures of non-validated models

 Contact ALCES for Judy E. Muir, M.Sc., R.P.Bio. Virgil C. Hawkes, M.Sc., R.P.Bio., Krysia N. Tuttle, M.Sc. and Tony Mo, 2011
2011

The Anthropocene: From Global Change to Planetary Stewardship

Will Steffen, A ° sa Persson, Lisa Deutsch, Jan Zalasiewicz, Mark Williams, Katherine Richardson, Ca

Over the past century, the total material wealth of humanity has been enhanced. However, in the twentyfirst century, we face scarcity in critical resources, the degradation of ecosystem services, and the erosion of the planet’s capability to absorb our wastes. Equity issues remain stubbornly difficult to solve. This situation is novel in its speed, its global scale and its threat to the resilience of the Earth System. The advent of the Anthropence, the time interval in which human activities now rival global geophysical processes, suggests that we need to fundamentally alter our relationship with the planet we inhabit. Many approaches could be adopted, ranging from geoengineering solutions that purposefully manipulate parts of the Earth System to becoming active stewards of our own life support system. The Anthropocene is a reminder that the Holocene, during which complex human societies have developed, has been a stable, accommodating environment and is the only state of the Earth System that we know for sure can support contemporary society. The need to achieve effective planetary stewardship is urgent. As we go further into the Anthropocene, we risk driving the Earth System onto a trajectory toward more hostile states from which we cannot easily return.

 Contact ALCES for Will Steffen, A ° sa Persson, Lisa Deutsch, Jan Zalasiewicz, Mark Williams, Katherine Richardson, Ca, 2011
2011

Modeling Rangeland Community Structure in ALCES Southern Alberta Sustainability Strategy (SASS)

Barry Adams and Brad Stelfox

Rangeland communities are not constant in structure (physiognomy), but change through time as they grow older, or when they are disturbed by various natural processes including fire, drought, and herbivory. Unlike forest communities, rangelands do not have to be reset to the youngest seral stage when they are affected by a natural disturbance. Instead, structural change varies depending on the intensity of the disturbance. The purpose of modeling rangeland in SASS is to simulate and compare rangeland structure under various future land use and development scenarios, and to use these results in modeling changes to wildlife habitat values. Modeling in SASS is at a regional scale and is over a 50-year time period. The study area is more or less comprised of the South Saskatchewan watershed, which is about 20% of the total area of Alberta.

 Contact ALCES for Barry Adams and Brad Stelfox, 2011
2012

Mayatan Lake State of the Watershed Report

Melissa Logan, P.Biol., Billie Milholland, B.A., and David Trew, P.Biol.

The purpose of this report is to summarize all available environmental information for Mayatan Lake and its surrounding watershed. This report also provides a benchmark against which future stewardship activities and best management practices aimed at maintaining and improving watershed health can be assessed. The information will provide landowners, stakeholders, Parkland County and the Mayatan Lake Management Association (MLMA) with the information needed to support sound management decisions and develop solutions to protect or enhance land and water resources in the watershed. It also serves as a localized component and example of NSWA’s larger basin planning initiative, the Integrated Watershed Management Plan for the North Saskatchewan River Basin.

 Contact ALCES for Melissa Logan, P.Biol., Billie Milholland, B.A., and David Trew, P.Biol., 2012
2012

Eating Tomorrow

Lorne Fitch, P. Biol.

It was a sight to behold and one greater to comprehend the eating of, that chocolate cream pie. We had whipped it together from graham cracker crumbs and chocolate pudding, shaken and then chilled in a snow bank on a backpacking trip. The anticipation of eating it brought me to the level of a child, thinking only of immediate gratification. My two companions showed considerably more restraint, electing to divide each of their respective thirds in half, to have a piece at breakfast the next morning. I ate my third immediately. The saved piece of pie was enclosed in a rock cairn to protect it from marauders. I was teased unmercifully about how good the remainder would taste in the morning, had I saved some of my pie. The early glow of morning light revealed the cairn had been transformed into a scatter of rocks. No pie remains were left and the aluminum pie plate retained gouges on its surface. A mule deer doe was beating a hasty retreat from the scene saving me from instant suspicion. But, a closer inspection of the crime scene with all the intensity of a CSI unit showed a porcupine was the culprit. Somewhere in the headwaters of the Castle River there may well be a line of porcupines still hardwired to remember a meal of non-wood, chocolate ambrosia tinged with a slight metallic aftertaste. It was my turn to laugh, since I had lost nothing in this porcupine perpetrated crime. The moral of the story, I pontificated, was that “gluttony is its own reward”. Saving a piece of the pie was foolish, because how could we predict the events of the future, and indeed the tragic loss of the saved pie? Eating it all, now, was the smart thing to do. It was only later, upon reflection that I realized how much the incident revealed of human nature and our province, if not the world.

Contact ALCES for Lorne Fitch, P. Biol., 2012
2012

Models and Data: What are they saying about cumulative effects on wildlife species important to the community of Fort McKay

Lorne Gould

Wildlife is an integral part of the Fort McKay’s culture. Since the start of development (late 1960s) there has been a transformation of traditional lands from boreal forest and wetlands into oil sands development (open pit mines, in situ operations, and associated infrastructure). The environmental impact assessments (EIAs) prepared by oil sands operators and proponents repeatedly claim that these developments will have little impact on wildlife populations and their habitats because reclamation will return the land to a productive state. Fort McKay Community members are skeptical of future reclamation success and believe that development already has negatively impacted certain wildlife populations. The Fort McKay also has concerns about the project by project review process and the assessment of cumulative effects. This report provides brief summaries of studies that show cumulative effects on wildlife important to the Fort McKay. This report also presents wildlife data from EIAs and the findings of a recent study on wildlife habitat models used in the oil sands region. Four wildlife species; moose, beaver, fisher/marten, and Canada lynx are emphasized because of their cultural importance. The moose and beaver are considered Cultural Keystone species for the Fort McKay Community (Garibaldi 2006). Canada lynx, fisher, and marten are furbearers vital to the Fort McKay’s traditional economy. Fisher and marten are lumped together because of the difficultly in differentiating their snow tracks in the field. Sources of information for this report are as follows: 􀁸 Results of the Fort McKay Specific Assessment (FMSA); 􀁸 Results of modeling completed for the Lower Athabasca Regional Plan (LARP) and Terrestrial Ecosystem Management Framework (TEMF); 􀁸 Aerial surveys completed by the Alberta Sustainable Resource Development (ASRD); 􀁸 Wildlife data collected in the oil sands region in support of environmental impact assessments; 􀁸 Population viability analysis (PVA) modelling reports completed in the oil sands region; and 􀁸 Analysis of habitat models used in the oil sands region completed by CEMA. In 2011, 1.7 million barrels of bitumen were produced in the oil sands region of Alberta. This quantity is expected to reach 3.5 million barrels per day by 2020 (Alberta Government 2012). We summarize modeling results that predict impacts from oil sands development. We also provide information that shows how the present project by project EIA process is failing to assess cumulative effects on wildlife. We provide recommendations that will reduce impacts and allow for the future recovery of wildlife in the Fort McKay’s Traditional Territory.

 Contact ALCES for Lorne Gould, 2012
2012

CUMULATIVE EFFECTS THRESHOLDS FOR ARCTIC GRAYLING IN THE WAPITI RIVER WATERSHED

Adam Paul Norris

Intensity and types of land use have changed rapidly in the last century and in north-western Alberta this has coincided with the decline of Wapiti River watershed Arctic Grayling (Thymallus arcticus) populations. Data on diurnal dissolved oxygen (DO), chemical and physical stream habitat data were collected in nine sub-watersheds of the Wapiti River with historically abundant Arctic Grayling populations. Levels and fluctuations of DO and temperature were related to the status of populations; five of the nine streams had higher temperatures and lower DO during summer, anoxic conditions during winter and extirpated populations. Amount of disturbed land and road density within sub-watersheds were inversely related to DO levels and population status. Cumulative effects modelling suggests a possible mechanism for these relationships is increased phosphorous runoff, leading to impaired habitat. These relationships and thresholds may be used as a management tool to maintain or restore Arctic Grayling and other stream fishes.

Contact ALCES for Adam Paul Norris, 2012
2012

Land and Water Impacts of Oil Sands Production in Alberta

Sarah Jordaan

Review of the Land and Water Impacts of Oil Sands Productions in Alberta

 Contact ALCES for Sarah Jordaan, 2012
2012

Nighttime lights as proxy for the spatial growth of dense urbanized areas

Nicola Pestalozzi

Nighttime lights constitute a very appealing database that can be used to measure various different aspects of the human footprint on the planet. The amount of research and the number of publications around this dataset confirm this, offering a broad spectrum of applications that involve economics, energy, society and environment. I chose to use them to study the spatial extension and the relative distribution of settlements around the Earth and their evolution over time. I analyzed the DMSP-OLS ‘stable lights’ database of the NGCD consisting in a catalog of world images of the last 19 years. I discovered that the mean center of lights is moving steadily to South-East. This reflects the extreme growth experienced by the urban centers in the developing countries, especially in Asia. I further developed a version of the Gini coefficient to compare the statistical spatial dispersion of nighttime lights, unexpectedly finding that all the countries show a very similar inequality value, quickly converging to the same coefficient by raising the lower threshold of light detection. Further, I analyzed the evolution of the lit area at a country level and in the largest urban agglomerations, finding that whereas most developing countries and cities are experiencing an incredible spatial growth in illumination, some ‘historical’ conurbations present rather constant or even decreasing emissions. This could be a signal of success of the light pollution abatement programs launched in the last years.

 Contact ALCES for Nicola Pestalozzi, 2012
2012

Social-Ecological Thresholds in a Changing Boreal Landscape: Insights from Cree Knowledge of the Lesser Slave Lake Region of Alberta, Canada

Parlee, B. L., K. Geertsema, and Lesser Slave Lake Indian Regional Council

Drawing on the traditional ecological knowledge (TEK) of the Lesser Slave Lake Cree, this paper shares understanding of how resource development has affected water, fish, forests, and wildlife as well as the well-being of Cree communities in the Lesser Slave Lake region of Alberta, Canada. In addition to descriptive observations of change, the narratives point to social-ecological thresholds or tipping points in the relationship of Cree harvesters to local lands and resources. Specifically, the study speaks to the echoing effects of ecological loss and degradation on traditional livelihood practices over the last 100 years highlighting the complexity of cumulative effects as well as the challenges of balancing resource development in the region with alternative land uses including those valued by Alberta’s Aboriginal peoples.

 Contact ALCES for Parlee, B. L., K. Geertsema, and Lesser Slave Lake Indian Regional Council, 2012
2012

Implications of changing environmetnal requiresments on oil sands royalties

E Valera and C.B. Powter

Examines relationships between elevating environmental costs of oilsands and government royalties

 Contact ALCES for E Valera and C.B. Powter, 2012
2012

Shell Jackpine Mine Expansion Project

Oil Sands Environmental Coalition

The Panel’s responsibilities to determine if the Project is in the public interest and determine if it will create significant adverse effects, is onerous. We believe it would assist the Panel in discharging its responsibility to protect the public interest and make its assessment of the residual impacts, if it ensured that mitigation will, in fact, be implemented and knew the status of its previous recommendations, and commitments made by the proponent on which the Panel and ERCB relied upon – particularly as it relates to Shell’s projects and the projects in the Muskeg River basin.

 Contact ALCES for Oil Sands Environmental Coalition, 2012
2012

Fresh: Edmonton's Food and Urban Agriculture Strategy

The City of Edmonton Food and Urban Agriculture Advisory Committee

This Strategy provides a singular opportunity to imagine how new approaches to food and urban agriculture can make Edmonton an even better place to live, work, play and invest. It’s no exaggeration to say that food matters to each of us every day, but we also need to consider how to make our city a more innovative and dynamic food and urban agriculture setting as we move into the future.

 Contact ALCES for The City of Edmonton Food and Urban Agriculture Advisory Committee, 2012
2012

Institutional requirements for watershed cumulative effects assessment and management: Lessons from a Canadian trans-boundary watershed

Poornima Sheelanere, Bram F. Noble, Robert J. Patrick

Watersheds are under increasing stress from the cumulative environmental effects of water and land use disturbances caused by both anthropogenic and natural causes. Yet, while the science of watershed cumulative effects assessment and management (CEAM) is advancing much less is known about the institutional and capacity requirements to implement and sustain watershed CEAM. Based on lessons from a transboundary watershed in western Canada this paper presents eight institutional requirements, or requisites, for the implementation of watershed-based CEAM. We suggest that effective watershed CEAM requires government leadership to move beyond the current inward focus on project approvals toward an outward focus on the cumulative effects of all disturbances in a watershed; complementary monitoring programs at the project and watershed scale, and a means to ensure the sharing of monitoring data across watershed stakeholders; and a nested planning framework to coordinate watershed planning objectives with individual project impact assessment and decision making. Results of this paper show that simply scaling up from individual project-based assessments to the watershed scale exposes many institutional constraints that can impede CEAM action.

 Contact ALCES for Poornima Sheelanere, Bram F. Noble, Robert J. Patrick, 2012
2013

Logging to Supply Timber vs. Logging to Supply Water Is there a Difference?

Nigel Douglas

In all of the long-drawn-out, at times acrimonious disputes over logging in Alberta’s southern Eastern Slopes, one question has continued to baffle observers. Why has the Alberta government, despite all of the mounting opposition, been so determined to push ahead with logging these precious watersheds when the economic benefits are so minimal and the environmental costs so high? One possible answer to that question has been hinted at in recent comments from government spokesmen in the media. What if the government is indeed logging full speed to maximize resource extraction from the forest, but the primary focus is not on the production of timber, but on the production of water? If you have a tunnel-vision focus on managing forests to supply one thing – be it timber or water – then other things, including wildlife and recreation are likely to suffer. This seems to be the case in Alberta.

 Contact ALCES for Nigel Douglas, 2013
Projects: 76-98 of 98
< 1 2 3 4
Items per page: 10 25 50