Sustainable Landscapes

This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and phosphorus in a LECA-based horizontal subsurface flow constructed wetland. Stormwater runoff for the period between January 2008 and June 2010 (30 months) was estimated for the drainage basin of the Vila Fernando wastewater treatment plant (constructed wetland system) and it was observed proportionality between the increase in surface runoff and the infiltration flow rate that reached the plant. The average stormwater infiltration rate that reached the plant was 67.4 m(3) d(-1) (77% of the influent flow rate into the plant). The 30 month monitoring campaign set up at one of the reed beds showed that stormwater infiltration led to a high variation of the hydraulic loading rate (HLR) throughout the bed, which affected its performance in the removal of organic matter, suspended solids and nitrogen. For a HLR below 20 cm d-1 the removal efficiencies for BOD5, COD and TSS doubled. The removal of nitrogen was too low and was associated with the weak development of nitrifying biofilm and the poor growth of reeds. However, it was observed a good relationship between the applied and removed loads for most of the parameters, which seems to indicate that the organic, solid, nitrogen and phosphorus loading rates influenced the respective removal rates. The use of a bed material with high specific surface area, such as LECA, can only improve the treatment capacity of horizontal subsurface flow systems if the organic and solid loading rates, as well as the HLR, can be effectively controlled.

Reclaimed water from small wastewater treatment facilities in the rural areas of the Beira Interior region (Portugal) may constitute an alternative water source for aquifer recharge. A 21-month monitoring period in a constructed wetland treatment system has shown that 21,500 m3 year−1 of treated wastewater
(reclaimed water) could be used for aquifer recharge. A GIS-based multi-criteria analysis was performed, combining ten thematic maps and economic, environmental and technical criteria, in order to produce a suitability map for the location of sites for reclaimed water infiltration. The areas chosen for aquifer
recharge with infiltration basins are mainly composed of anthrosol with more than 1 m deep and fine sand texture, which allows an average infiltration velocity of up to 1 m d−1. These characteristics will provide a final polishing treatment of the reclaimed water after infiltration (soil aquifer treatment (SAT)),
suitable for the removal of the residual load (trace organics, nutrients, heavy metals and pathogens).
The risk of groundwater contamination is low since the water table in the anthrosol areas ranges from 10 m to 50 m. On the other hand, these depths allow a guaranteed unsaturated area suitable for SAT. An area of 13,944 ha was selected for study, but only 1607 ha are suitable for reclaimed water infiltration.
Approximately 1280 m2 were considered enough to set up 4 infiltration basins to work in flooding and
drying cycles.

Van Devender T., Espinosa-García, F.J., Harper-Lore, B.L. and Hubbard, T. (Eds.) 2009. Invasive Plants on the Move. Controlling them in North America. Arizona-Sonora Desert Museum  Press, Tucson, Arizona, U.S.A. 424 pp. ISBN 1886679282, 9781886679283


I  INTRODUCTION
Preface
Bonnie L. Harper-Lore
Weeds Across Borders – A History of Weed Awareness in North America

Overview
Francisco J. Espinosa-García and Thomas R. Van Devender
Cooperation among North American Countries Dealing with Weeds: Advances and Challenges.

II  NATIONAL STATUS ON INVASIVE PLANTS AND INTERNATIONAL COOPERATION

1. Allison, Kenneth
Canada: National Invasive Alien Plant Regulations and Initiatives


2. Tasker, Alan V.
United States: Department of Agriculture’s Animal & Plant Health Inspection Service Plant importation Regulations and Initiatives

3. Espinosa-García, Francisco J., and Heike Vibrans
Mexico: The Need of a National Weed Management Strategy

4. Arriaga, Laura
Mexico: Current Policy Response to the he Invasive Species

5. Espinosa-García, Francisco J., José L. Villaseñor, and Heike Vibrans.
Mexico: Biodiversity, Distribution, and Possible Impacts of Exotic Weeds

6. Grosse, Andrea, Silvia Ziller, and Elizabeth Sellers
The Americas: Invasive Species Information Management and Exchange. The IABIN Invasives Information Network (I3N)

III INVASIVE SPECIES ACCOUNTS AND FLORISTICS

7. Prasad, Raj, Jordon Brenner, and Satish Bundel
British Columbia: Invasive Exotic Weeds on Federal Lands in and Management Tools

8. Ali, Shaffeek
Alberta: Weed Issues and Initiatives

9. Solomeshch, Ayzik, Sharon N. Long, Michael G. Barbour, and Alison M. Berry. 
California: Floristic Composition of Roadside Grasslands inYolo County

10. Van Devender, Thomas R., Richard S. Felger, Ana Lilia Reina-Guerrero, and J. Jesús Sánchez-Escalante
Sonora: Non-native and Invasive Plants

11. León de la Luz, José L., M. Domínguez-L., R. Domínguez-C., and Thomas R. Van Devender
Baja California Sur: Invasive Weeds

12. González-Elizondo, M. Socorro, M. González-Elizondo, J. A. Tena-Flores, Irma L. López-Enriquez, and Jeffrey R. Bacon
Durango: Invasive Alien Plants

13. Serrano-Cárdenas, Valentina, P. Balderas-Aguilar and Ricardo Pelz-Marín
Querétaro: Invasive Weeds in Natural Semidesert


IV INVASIVE SPECIES, DISTURBANCE AND LOCAL DIVERSITY

14. Smith, Derald G., and Cheryl M. Pearce
Increased Saltcedar (Tamarix) Seed Production and Regional Invasion from Large Reservoirs During Severe Droughts in the Northern Great Plains

15. Kennedy, Sheilah, and Bob Parsons
Binational Efforts to Control Invasive Species in Washington and British Columbia

16. Corral-Díaz, Rafael, and Helvia Pelayo
Non-native Plants and Vegetation and along the Río Grande in Urban Ciudad Juárez, Chihuahua

17. Martínez-Díaz, Gerardo, and J. Jiménez-León
Weeds in Agricultural Crops in La Costa de Hermosillo, Sonora, Mexico

18. Alfaro-Rodríguez, Lucía, and Laura Arriaga
Weeds and Disturbed Habitats of the Cape Region of Baja California Sur, Mexico

V  INVASIVE SPECIES DISTRIBUTION AND IMPACTS

19. Darbyshire, Stephen, and Kenneth Allison
Dispersal of Weeds through Marine Transport Disaster

20. Pearce, Cheryl M., and Derald G. Smith
Rivers as Conduits for Long-Distance Dispersal of Introduced Weeds: Example of Russian Olive (Elaeagnus angustifolia) in the northern Great Plains of North America

21. Dimmitt, Mark A., and Thomas R. Van Devender
Sahara mustard (Brassica tournefortii): A New, Serious Threat to Low Desert Ecosystems in the southwestern United States and northwestern Mexico.

22. Lyons, Kelly G., Baruk G. Maldonado-Leal, and Gigi Owen
Community and Ecosystem Impacts of the non-indigenous C4 Buffelgrass (Pennisetum ciliare) in the Sonoran Desert, Sonora, Mexico

23. Nagler, Pamela L., Edward P. Glenn, Kim A. Franklin, Derrick Lampkin, and Alfredo R. Huete
Remote Sensing Methods to Monitor Buffelgrass (Pennisetum ciliare) and Native Ecosystem Productivity in the Plains of Sonora, Mexico

VI  INVASIVE SPECIES MANAGEMENT AND CONTROL

24. Dudley, Tom L.
Biological Control of Saltcedar in North America

25. Fletcher, April
Invasive Plant Species on U.S. Fish and Wildlife Service Refuges in the Southwestern United States

26. Ford, Cathy
Integrated Vegetation Management for Roadsides in Idaho

27. Renz, Mark J., Curtis Deuser, B. Hamilton, C. Nelson, María Ryan, and J. F. Makk
Management of Camelthorn (Alhagi maurorum) along Riparian Corridors in Nevada.

28. Best, Christopher F.
Fighting Weeds with Weeds: Battling Invasive Grasses in the Río Grande Delta of Texas

29. Langeland, K. A., A. P. Ferriter, C. S. Silvers, and P. D. Pratt
TAME Melaleuca  - an Areawide Pest Management Initiative in Florida

VI  SOCIETAL INVOLVEMENT IN PLANT MANAGEMENT

30. Westbrooks, Randall G., and Robert Eplee
Evolution of Early Detection and Rapid Response as a Preferred Management strategy for New and Emerging Invasive Plants in the United States

31. Ericson, Jenny A., Tani Hubbard, Marilyn Hanson, Dave Barnett, and Giselle Block.
Engaging Volunteers in Invasive Species Management in the United States

32. Darin, Gina, and Steve Schoenig
Combining Formal Weed Eradication Programs with Local Weed Management Areas for Early Detection and Rapid Response of Invasive Weeds in California

33. Marilyn Hanson, Doug Siegel, Barb Skye Siegel, Carianne Funicelli, and Aaryn Olsson
Sonoran Desert Weedwackers: A Model for Controlling the Spread of Invasive Grasses

34. Rutman, Sue
Managing Invasive Plants on the Dry Border, Organ Pipe Cactus National Monument, Arizona

35. Ibarra-F., Fernando A., Martha H. Martín-R., F. G., Denogean-B., and R. Aguirre-M.
Buffelgrass, Cattle, and the Sonoran Desert

36. Franklin, Kim A., Edward P. Glenn, Kelly G. Lyons, Pamela L. Nagler, Francisco Molina-Freaner, and Theresa Markow
Rates of Buffelgrass (Pennisetum ciliare) Land Conversion in the Plains of Sonora, Mexico

The rapid expansion of the production of agricultural commodities such as beef, cocoa, palm oil, rubber and soybean is associated with high rates of deforestation in tropical forest landscapes. Many state, civil society and market sector actors are engaged in developing and implementing innovative interventions that aim to enhance the sustainability of commodity supply chains by affecting where and how agricultural production occurs, particularly in relation to forests. These interventions – in the form of novel or moderated institutions and policies, incentives, or information and technology – can influence producers directly or achieve their impacts indirectly by influencing consumer, retailer and processor decisions. However, the evidence base for assessing the impacts of these interventions in reducing the negative impacts of commodity agriculture production in tropical forest landscapes remains limited, and there has been little comparative analysis across commodities, cases, and countries. Further, there is little consensus of the governance mechanisms and institutional arrangements that best support such interventions. We develop a framework for analyzing commodity supply chain interventions by different actors across multiple contexts. The framework can be used to comparatively analyze interventions and their impacts on commodity production with respect to the spatial and temporal scales over which they operate, the groups of supply chain actors they affect, and the combinations of mechanisms upon which they depend. We find that the roles of actors in influencing agricultural production depends on their position and influence within the supply chain; that complementary institutions, incentives and information are often combined; and that multi-stakeholder collaborations between different groups of actors are common. We discuss how the framework can be used to characterize different interventions using a common language and structure, to aid planning and analysis of interventions, and to facilitate the evaluation of interventions with respect to their structure and outcomes. Studying the collective experience of multiple interventions across commodities and spatial contexts is necessary to generate more systematic understandings of the impacts of commodity supply chain interventions in forest-agriculture landscapes.

Urbanization has destroyed and fragmented previously large areas of natural habitat. Small remnants that still exist in numerous cities will be unable to sustain many viable wild plant populations if they do not expand into the surrounding urban matrix. Residential gardens surrounding such remnants, and which form a significant component of urban green space in many cities, could play a role in redressing this problem. Riccarton Bush, a 7.8 hectare forest remnant, and its surrounding suburban residential area, in Christchurch, New Zealand, is a good example. Over 125 years the reported number of native vascular plants in the bush has declined by a third. My study was an attempt to understand: 1) the ecological, social and cultural factors influencing the dispersal and regeneration of 12 native bird-dispersed woody species from Riccarton Bush, into surrounding residential properties; and 2) the potential role residential properties could play in the future of the bush. To examine these diverse factors I adopted an interdisciplinary research approach combining methodologies, concepts and theories from ecology and the social sciences. In a broader context my work was an attempt to demonstrate how urban ecology can further develop and strengthen by adopting and integrating new methodologies, theories and concepts.

The ecological component involved recording individuals of the study species found on 90 randomly selected properties within a 1.4 km radius of the bush. Soil samples were also collected from 31 of those properties and placed in a glasshouse and the study species that germinated were recorded. Results showed some species, particularly kahikatea (Dacrycarpus dacrydioides), the most abundant species in the bush, are being dispersed and establishing on properties predominantly within 250 m of the forest margin. These juveniles are not reaching maturity as most gardeners tend to remove all non-planted woody species. Qualitative interviews with 16 residents and a quantitative survey of the residents of 85 of the properties provided insights into the social context which these natural processes were operating.

Using notions of place and performance I argue that gardens are continuously created and recreated by humans and non-humans. Residents attempt to create and maintain a garden that fulfils their individual and familial needs and desires (e.g., aesthetics, leisure and privacy), and public responsibilities such as ensuring they have a ‘neat’ and ‘tidy’ garden. This involves selecting plants for colour, shape and the care they require, and encouraging certain performances (e.g., flowering) while controlling other undesirable plants and performances (e.g. growth, spread and shading). While people make connections between native plants, belonging and identity; the ‘scientific’ demarcation between native and exotic species often becomes obscured as the garden is co-created by people and plants. Some plants become more significant than others but usually this is attributable to their performances rather than whether they are native or exotic.

Residential gardens have the potential to play a major role in the conservation of species restricted to urban remnants. My research suggests that although the potential exists for woody species restricted to Riccarton Bush to naturally regenerate in nearby gardens, this will not happen without human intervention. Plants will need to be eco-sourced and propagated to avoid detrimental impacts on the genetic health of remnant populations, and then actively planted in gardens. The success of such planting initiatives will be increased by providing residents with information about the plants that are suitable for their performative needs and desires (e.g., the size, colour, and maintenance requirements of plants) and, most importantly, control over the location of plantings. In concluding, I argue that by adopting new concepts, theories and methodologies, the productivity, creativity and relevance of urban ecology can be significantly enhanced.

At the global, regional and national levels our environmental base is being rapidly degraded. Soil, air and water quality, biodiversity, atmospheric carbon loading, pollutant levels and marine habitats are all past or rapidly approaching the point of imminent collapse. This environmental disaster is not just a disaster for conservationists and nature lovers, it is also an economic disaster. As this paper shows, our economy is inextricably linked to and dependent upon our natural resource base, and as such preserving our ecosystem infrastructure is a matter of economic imperative. In the South African context the majority of intact ecosystem infrastructure exists in the Eastern Cape, Kwa-Zulu Natal, Mpumalanga and Limpopo in areas that contain most of the country's small- scale farmers and communal lands. Like the rest of the globe, these areas are under threat from poor land-use practices and as such developing effective strategies for investment in the ecosystem base in these areas is vital to the integrity of the services these ecosystems provide to the economy. It is recognised that the state is putting considerable resource behind preserving our natural capital, but this is proving insufficient. This paper advocates a number of mechanisms that can yield positive returns to private investment by unlocking additional value streams that can be channelled into environmentally sustainable, commercially oriented small-scale agricultural practices

Considering that tourism is an activity that contributes to the well-being of rural communities , a method is proposed to identify and evaluate tourist attractions, based on their landscape quality and their social viability. The method consists in the design and combination of scenic, functional and interpretive indicators to evaluate the quality of the landscape; and in the recognition, through interviews and surveys, of the perception that the local community has of tourism, their interest and willingness to participate and their level of organization. The research was developed in Atlautla, a municipality near Mexico City. Twenty-nine tourist attractions were identified, including seven high-quality landscaping and preference, from which it would be viable to expand the benefits of tourism activity in the community. Although the community has sufficient knowledge, interest and willingness to participate, it lacks adequate organizational capacity.

Horizontal subsurface flow (HSSF) constructed wetlands are widely used for wastewater treatment but there’s still a lack of information on flow characteristics changes throughout the porous bed over time. The continuous growth of roots, the adsorption, sedimentation and precipitation of wastewater compounds and the biofilm release over operation time leads to the development of stagnated areas, the appearance of hydraulic short-circuiting and variations in dispersion conditions, which affect substrate distribution throughout the bed and, therefore, may worsen the overall performance of the system. In order to enable a better understanding of the transport mechanisms throughout the bed, two series of tracer tests were performed in a laboratory HSSF system at the hydraulic loading of 4.7x10-3 m3 m-2 h-1. The first series was executed with the bed without vegetation and the second with the bed already colonized with Phragmites australis after an operation period of eight months at an average organic loading of 12 g m-2 d-1 COD. The magnitude of longitudinal dispersion was estimated both by a curve fitting technique using the non-linear least square optimization method (LSOM) and using the moment method (MOM) over the advection-dispersion-reaction equation. The flow regime and the extension of dead volumes were estimated by the same curve-fitting technique over the multiple tanks in series model (MTS). The results showed that the development of plants and biomass did not contribute for a significant amount of longitudinal dispersion in the overall media length. However, the dispersion was very strong in the inlet section, where the dead volumes increased approximately 65% within the colonized bed. The flow regime may be considered as plug flow throughout the overall length and the tracer retention was associated with dispersion and internal recirculation and, additionally, for Series II it was associated with the occurrence of clusters of biomass and roots. The MTS better explain the tracer results for the overall media length. The MOM seems to be inadequate for estimating Pe leading to underestimated values when compared with the ones calculated by LSOM.

Most of the wastewater treatment systems in small rural communities of the Cova da Beira region (Portugal) consist of constructed wetlands (CW) with horizontal subsurface flow (HSSF). It is believed that those systems allow the compliance of discharge standards as well as the production of final effluents with suitability for reuse. Results obtained in a nine-month campaign in an HSSF bed pointed out that COD and TSS removal were lower than expected. A discrete sampling also showed that removal of TC, FC and HE was not enough to fulfill international irrigation goals. However, the bed had a very good response to variation of incoming nitrogen loads presenting high removal of nitrogen forms. A good correlation between mass load and mass removal rate was observed for BOD5, COD, TN, NH4-N, TP and TSS, which shows a satisfactory response of the bed to the variable incoming loads. The entrance of excessive loads of organic matter and solids contributed for the decrease of the effective volume for pollutant uptake and therefore, may have negatively influenced the treatment capability. Primary treatment should be improved in order to decrease the variation of incoming organic and solid loads and to improve the removal of COD, solids and pathogenic. The final effluent presented good physical–chemical quality to be reused for irrigation, which is the most likely application in the area.

A monitoring campaign in a horizontal subsurface flow constructed wetland under the influence of transient loads of flow-rate, organic matter, nitrogen and suspended solids showed an irregular removal of COD and TSS and lower both removal efficiencies and mass removal rates than the ones observed in other studies for similar operating conditions. This circumstance is associated to the presence of large amount of particulate organic matter from non-point sources. The mass removal rate of ammonia increased 39% as both the water and soil temperatures increased from weeks 1–8 to weeks 9–14. A good correlation between mass load and mass removal rate was observed for all measured parameters, which attests a satisfactory response of the bed under to transient loads.