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The New Wild: Can Invasives Actually be Good?

the new wild Most of us have bought into an ecological ideology where invasive species do not exist and native plants thrive in a balanced system. In the design world you get points for sustainability if you remove invasives and use native plants. But a new paradigm is evolving as scientists study how natural systems adapt to human impacts.

In “The New Wild – Why Invasive Species will be Nature’s Salvation” Fred Pearce argues that there is no such thing as pristine nature. In addition, nature is neither “stable nor perfectible.” However, current conservation efforts seek to return ecosystems to a static, pre-human state by protecting endangered and weakened species, thereby breaking evolution, holding back adaptation. Pearce writes, “If we want to assist nature to regenerate, we need to promote change, rather than hold it back.”

Pearce argues that invasives, and aliens in general, may be our best bet to heal “the damage done by chain saws, plows, pollution and climate change.” For example, the spreading of Japanese Knotweed may be an indication that nature is bouncing back, reinventing itself for the twenty-first century. In many cases, those invading species accused of crowding out natives have simply taken up space where natives can no longer survive and are declining. In other instances, such as with the water hyacinth, alien invaders may take over due to pollution, and in fact provide an important pollution filtration role. And when pollution decreases, so does the alien species.

While Pearce does acknowledge that there are horror stories about alien species disrupting ecosystems, most of the time introduced species die out or settle down. He and a growing number of scientists claim that aliens have greatly increased biodiversity and can provide important roles in “novel ecosystems” – composed of natives and those introduced by humans. As environmentalists, Pearce believes we should embrace this new ecology and celebrate nature’s capacity for change within the New Wild.

This is a provocative new line of thinking. What’s your opinion? Several of us in the office are also reading “Bringing Nature Home – How You Can Sustain Wildlife with Native Plants” by Doug Tallamy. Two very different schools of thought. More to come later…

Solving Typical Rain Garden Problems

Many of us embraced rain gardens in the past several years for their ability to mitigate storm water runoff and to help cleanse groundwater of pollutants.
We love rain gardens; we really do. It’s just that sometimes rain gardens don’t love us back. Here are some reasons that rain gardens don’t always work, and the most likely solutions:
1. Problem: Lack of an underdrain. Rain gardens are designed to infiltrate storm water into the soil. But sometimes they fill up faster than they can drain.
Solution: Install a 4’’ perforated pipe underdrain below the rain garden basin. This underdrain operates as a kind of relief valve if excess water accumulates in the rain garden. The underdrain is connected to an outlet structure, which is there to function during intense storm events when the basin fills up.
2. Problem: Clay and silt clog the perforations in the 4” underdrain pipe.
Solution: If the rain garden stops draining, the underdrain pipe may be clogged. Flush the underdrain pipe with a garden hose via the outlet structure.
3. Problem: Sediment washes into the rain garden from surrounding surfaces, filling in all the desirable and needed air pockets in the mulch, preventing infiltration.
Solution: Protect the rain garden from sedimentation with a silt fence or filter sock until the surrounding areas are stabilized with vegetation or paving.
4. Problem: Water won’t seep into the soil. Sometimes heavy construction vehicles compress subgrade soil to a degree that water cannot infiltrate.
Solution: Loosen the subgrade before constructing the rain garden.

Green Roof Tour at the Pittsburgh Zoo


Schizachryium scoparium
Carex pennsylvanica
Carex pennsylvanicaSchizachryium scoparium

On October 16, 2013, Jim Pashek joined old friends on a “Rooftop Rendezvous at the Zoo” sponsored by Green Building Alliance.  Jim was involved with the project management of the “New Zoo” beginning in the early 1980’s and had the pleasure to work over the years with our tour guides that night, Frank Pizzi and Marjorie Marks.

What a specacular demonstrtion rooftop garden. About half of the planted roof area is an “extensive” roof garden with 3-4 inches of special soil mix. The other half was this lush “intensive” rooftop garden of plants placed in a special soil mix ranging from 3-36 inches.  You can tell from the photos that they have been successful to identify species that can thrive in a very hot micro climate and in very shallow soils.The garden got me thinking

that the rooftop garden at Pashek Associates is ready for an overhaul.  This “extensive” garden is planted in trays on 4 inches of special soil mix. We decided to try four varieties of sedums to see which would survive in very difficult site conditions. They all survived and have never been watered since after the first growing season.Some plants that we may plant include Carex pennsylvanica (the small grass clump like plants), which is one of the few sedges that tolerates very dry conditions.  I find it interesting that I would normally use Carex p. in part to full shade but at the Zoo, it is doing great in full sun.  I also think we will try in our rooftop garden Schizachryium scoparium, a plant that is home on the prairie and thrives in hot, dry, well drained conditions (the typical rooftop garden).

Zoo Rooftop Garden - Extensive Plantings
Zoo Rooftop Garden – Extensive Plantings

Frank, thank you for a very informative presentation and tour of the Zoo’s rooftop garden gem. Thanks also to the GBA for arranging the tour.  We look forward to another rooftop garden tour sponsored by GBA in November at the Convention Center, a green roof designed by Pashek Associates and installed by Eilser Nurseries. Maybe next summer we will have more pictures of our newly renovated rooftop garden at Pashek Associates.  Please stop in and ask for a tour of our garden here on the Northside.

In Pittsburgh, Green is in the Air

It’s summer and that means the City is green with trees.  Not only are plants in the midst of their growing season, but people are in the midst of launching green initiatives.  Last week we attended a poster  session during the Who’s Who in Green Infrastructure Implementation event hosted by the Green Building Alliance and organized by 3 Rivers Wet Weather.  The event was packed with people interested in sharing their projects and learning more about green infrastructure.

We brought along information on several of our green roof, green school, and green park projects.  At an elementary school in New Castle we were able to reduce the amount of stormwater piping and decrease the size of underground storage tanks through a combination of planted meadow areas, rain gardens, pervious overflow parking and fire lane, and a series of vegetated swales.
Y:New Castle Lockley Elementary School - 10029Rendering Bases
For Whitehall Road Regional Park in Centre County, we are pulling out all the green stops by including rain gardens, steep slopes with meadows, vegetated buffer strips, infiltration trenches, and cisterns.  In addition, 44% of the total parking spaces are stabilized turf, which further reduces the amount of stormwater runoff.
Whitehall Road MP NO Buildings rev TJ
Our last poster featured our designs for the David Lawrence Convention Center green roof, the Allegheny County Office Building green roof, and the rain gardens at Seven Springs.

This morning over 80 people packed a Pittsburgh Zoo conference room to kick-off this year’s Green Workplace Challenge (GWC), a program of Sustainable Pittsburgh.  We took part last year in the challenge and are excited to enter again this year with the revamped program.

This year’s GWC promises to be bigger, better, and have an even larger environmental impact than last year.  There are more points to acquire, more actions to take, and more resources available to help guide your business, non-profit, university, or municipality towards becoming more sustainable as well as saving money.
Last year we saved 19.9% on our energy usage without spending a lot of money.  This year we want to reduce our energy usage even further by tightening up our building envelope.  We will also start to phase out our older lighting with new highly efficient lighting.  We highly recommend any organization in Southwestern Pennsylvania sign up for this friendly competition before the deadline on July 31st, 2013.  Good luck to all participants.  Together, we can make a huge impact!

County Building Green Roof Measures its Own Effectiveness

photo-224x300You may think of the Allegheny County Office Building, 452 Forbes Ave., Pittsburgh, as the place to go if you have a question about your property assessment.

But this historic building is also the site of a beautiful, functional and productive green roof, designed with the help of Pashek Associates.Green roofs benefit the local environment by reducing storm water runoff; keeping buildings warmer in winter and cooler in summer; evening out daily temperature swings; and helping to mitigate the heat island effect.

The County Office Building green roof, completed in 2010, is now growing into its role as a powerful tool for protecting the environment

A network of sensors embedded in the soils monitor performance of this roof compared with a conventional “control” roof. The sensors measure roof temperature, soil moisture, water flow and water retention, with data collected every 15 minutes. Over time, this information will demonstrate the valuable role that green roofs can play in easing some of the damaging effects that development has on our environment.

Here is an example of the data that can be seen by visiting the monitoring website. This example compares temperatures in a one-month period on the control roof (top line) with temperatures recorded by two sensors on the green roof (bottom two lines).


The green roof includes four different types of growing conditions, and over time it will also be possible to learn through the monitoring system how each type performs compared with the others. They are:

  1. Intensive – 8 to 12 inches of soil and growing shrubs and plants needing the soil depth.
  2. Semi-intensive – 6 inches of soil and able to grow plants and shrubs.
  3. Roll out Mat – set on 4 inches of soil, this pre-grown sedum mat provides instant cover.
  4. Tray system – easy to install, pre-grown sedum and lightweight.

Trail Planning in at Slippery Rock University

Slippery Rock University graduate students conducted a highly successful public meeting on campus trails October 16 with the help of Jim Pashek, President of Pashek Associates. Over 80 people attended the workshop that SRU-300x199included presentations of existing conditions, facilitation of small group discussions at 16 tables and, after everyone had an opportunity to express their top issues, voting was conducted to prioritize those issues.

Jim coached the Sustainable Landscapes class on ways of making public meetings more engaging and emphasized strategies that encourage the building of trust between meeting facilitators and attendees.  After the meeting, the class acknowledged their enthusiasm about their roles in the public meeting and were amazed at how participants became excited to share their concerns and expectations.

The public meeting was part of a larger trail planning process that John Buerkle, principal at Pashek Associates, was assisting the graduate students with.  He has worked with the students on how soils, topography, and vegetation impact both the design and ability to maintain trails. They also looked at logical connections through the campus.

The public meeting was held in the new Robert M. Smith Student Center, a beautiful space for the meeting.  Kudos to our friends at DRS for their work on that building.

Pashek Associates Sustainability Policy

As Landscape Architects, Community Planners, and Parks and Recreation Practitioners, we have long been in the business of working with natural processes, improving efficiencies, and developing innovative ideas for the pashek associates think greengood of the community. We have continually searched for the most sustainable solutions in design and planning. We believe it is the right thing to do.

As a firm, we strive to become sustainable through the following actions:

  • Promote sustainability through design and planning

– Spec sustainable products that are durable, reusable, recyclable, made with recycled content, use less packaging, and/or made from renewable resources.

– Use stormwater Best Management Practices.

– Use smart growth, transit oriented development, and other sustainable strategies in community planning and urban design.

– Protect and/or restore the environment by designing with ecological and natural processes in mind

– Use other sustainable sites principles found in LEED and the Sustainable Sites Initiative

  • Use a democratic design and planning process to support the needs of whole communities

– Ensure that all meeting participants are equally heard regardless of race, gender, ethnicity, disability, sexual orientation, or age

  • Educate our clients and friends about the importance of sustainability

– Promote sustainable design solutions to clients by educating about their benefits

  • Implement sustainable actions in the workplace and at home in our communities

– Follow the Pashek Associates’ sustainable office policies in order to reduce energy, water, air pollution, and waste.

– Set an example in our individual neighborhoods / communities by following the same policies at home.

Pashek Asscoiates is building a culture of responsibility that encourages every employee to ask the questions that lead to more sustainable processes and practices, and help our firm support a sustainable future.

Pashek Associates Leading the Pittsburgh Green Workplace Challenge in Small Business Category

Bike-Friendly-Employer-224x300The Pittsburgh Green Workplace challenge enables businesses to participate in a friendly challenge program where they can receive recognition for their sustainable actions and achievements.

Pashek Associates is leading 12 businesses in the small business category (less than 50 people).

According to Valerie Patrick, PhD and Sustainability Coordinator for Bayer Corporation, “sustainability is a way of thinking and applies to every aspect of our work.” We couldn’t agree with her more.

Pashek Associates received points by tracking utility bills using an EPA website, being a bike friendly business, having a Prius for a corporate car, and planting native plants on the roof of their building. Green office policies of using washable cups and recycling also contributed to the firm’s leadership position in the challenge. Next up is an energy audit to begin reducing energy demand and our carbon footprint.

For more information, or if you are interested in signing up for the Challenge, please see the Pittsburgh Green Workplace Challenge Website.