appear adapted to wet equatorial habitats, but wet evergreen species do not appear to migrate into drier habits. Of 65 common urban trees for Singapore ( Tee and Wee, 2001 ), 37% were deciduous species from monsoonal areas. Seventeen species on the
Roger Kjelgren, Yongyut Trisurat, Ladawan Puangchit, Nestor Baguinon, and Puay Tan Yok
Nisa Leksungnoen, Roger K. Kjelgren, Richard C. Beeson Jr., Paul G. Johnson, Grant E. Cardon, and Austin Hawks
Urban landscape plants are often grown well beyond the environmental boundaries of their native range, particularly in regard to precipitation. Irrigation mitigates water stress for plants from mesic habitats grown in arid region urban landscapes
Carter M. Westerhold, Samuel Wortman, Kim Todd, and Douglas Golick
; Sirohi et al., 2015 ; Threlfall et al., 2015 ; Wray and Elle, 2015 ). Because of the relatively small functional requirements, habitat range, short life cycle, and nesting behavior of pollinators, urban areas can be suitable places devoted to their
Chalita Sriladda, Heidi A. Kratsch, Steven R. Larson, Thomas A. Monaco, FenAnn Shen, and Roger K. Kjelgren
Across the arid to semiarid U.S. Intermountain West (IMW) human populations increase but water supplies do not. Combined with cyclic drought, water shortages in IMW urban areas challenge managers to conserve water in irrigated urban landscapes
Roger Kjelgren, Lixue Wang, and Daryl Joyce
climate change. Although Australia's population is mostly concentrated in major urban zones along the higher rainfall seaboards, even these areas are affected by drought ( McWilliams, 1986 ). Similarly, the rapidly growing western United States is being
Michele L. Crawford, Paula S. Williamson, Tina M. Waliczek, David E. Lemke, and Thomas B. Hardy
Very few ecosystems in the world are completely free of introduced species, and an increasing proportion of habitats are becoming dominated by them ( Pysek and Richardson, 2010 ). Invasive species decrease species diversity ( McGeoch et al., 2010
Aaron G. Anderson, Isabella Messer, and Gail A. Langellotto
Narango et al. (2017) suggested that urban plantings should include native plant species to provide improved habitats and sustain native fauna. When considering bees (Anthophila) in particular, many species are generalists and can be found broadly
Margaret From and Paul E. Read
Platanthera praeclara, commonly called western prairie fringed orchid, is a showy forb native to seven states and one Canadian province. The species had resisted previous attempts at propagation. Small, isolated populations in the sandhills region of western Nebraska are disjunct and visitation by natural pollen vectors appears to be in decline. Modern cultivation practices and other habitat encroachment factors, including urban development, recreational activities, and natural fluctuations in seasonal water availability all have the potential to exert pressure on current populations. Federal and state permits have allowed a limited hand-pollination study to be conducted on federal land. Hand-pollinated plants showed a greater fruit production compared to control plants receiving no human pollination assistance. Germination studies were conducted using aseptic in vitro techniques. The microscopic seeds possess testa that are extremely hard and resistant to liquid absorption, which presents challenges to germination in vitro. These challenges will be discussed. Alternating cold treatments with room temperatures appeared necessary to promote protocorm development after germination. Three media tested produced varying germination responses. Juvenile plants produced through micropropagation can offer propagules for possible future reintroduction efforts of this protected species.
Guillermo Cardoso, Roger Kjelgren, Teresa Cerny-Koenig, and Rich Koenig
Low water landscapes are increasing popular and important in the urban areas of the Intermountain West (IMW). Perennial wildflowers are an essential part of low water landscapes, and are a dominant plant type in IMW native habitats. We compared pot-in-pot (PIP) vs. conventional above-ground (CAG) production of six IMW native wildflower species, Mirabilismultiflora, Aquilegia caerulea, Penstemon palmeri, Polemonium foliosissimum, Sphaeralcea grossularifolia, and Penstemonstrictus in #1 (4-L) containers. Media temperature, container-plant water loss, stomatal conductance, and growth were measured during two production cycles per year over 2 years. Growing medium temperatures in the PIP system averaged 10 °C cooler than in the CAG system. Consistent with cooler growing media, overall water loss of PIP-grown plants averaged 10% lower than plants grown in the CAG production system. Lower growing media temperatures apparently affected transpiration, as stomatal conductance was about 60% higher in the PIP system as compared to the CAG-grown plants. The integrated effect of lower growing media temperatures on plant performance resulted in about one-third greater top and root growth for plants growing in the PIP system compared to those in the CAG system. Pot-in-pot production may be an economically suitable nursery system for producing IMW native perennial wildflowers by reducing water loss and enhancing growth.
Hala G. Zahreddine, Daniel K. Struve, and Salma N. Talhouk
The Mediterranean region is a center of great plant diversity, harboring around 25,000 plant species, more than 20% of them endemic. Since the last Lebanese flora record in 1966, the country has experienced habitat fragmentation and destruction, due to overgrazing, overexploitation of natural resources, and urban expansion. A large number of Lebanese tree species have unexplored economic potential as either ornamental or medicinal plants. This study aimed at exploring the effects of two nitrogen fertility treatments on the growth and water use of 2-year-old Cercis siliquastrum seedlings. C. siliquastrum seeds were collected from different locations and mother trees in Lebanon in mid-Aug. 2001. Two-year old plants were then transplanted into 3-gal. containers and were randomly assigned to one of two N fertility programs, 25 ppm or 100 ppm. Plants from all redbud sources were significantly taller in the low N treatment and had significantly higher RGR than plants growing at 100 ppm N. On the other hand, plants growing at 100 ppm N level had significantly higher LAR and lower NAR than plants growing at 25 ppm N. There were significant differences in LAR and plant heights among the different sources. Water use was conducted monthly. It ranged from 3.6 × 10-4 to 1.3 × 10-3 g·cm Ht-1 per hour at 25 ppm and from 2.6 × 10-4 to 1.3 × 10-3 g·cm Ht-1 per hour at 100 ppm N through the experiment.