Journal: Ecological Entomology
Location: ?, Canada

The Elm Spanworm hatching boom is 2 weeks after the Sycamore Maple budburst. 85% more eggs were laid on the lower trunk than the crown (although those in later stages of development moved up towards the crown) and it had nothing to do with avoiding parasites (only one pupa was parasitised) or getting better quality leaves, although feeding on older leaves (three leaves expanded per bud) significantly improved the caterpillars’ chance of surviving to adulthood (90%, or 45% higher than when feeding on on younger leaves). Sycamore Maple leaves mature acropetally (from the base up).

Elm Spanworm – Ennomos subsignaria
Sycamore Maple – Acer pseudoplatanus

Fry HRC, Quiring DT, Ryall KL, Dixon PL, 2009. “Influence of intra-tree variation in phenology and oviposition site on the distribution and performance of Ennomos subsignaria on mature sycamore maple.” Ecological Entomology, DOI: 10.1111/j.1365-2311.2009.01091.x
Affiliations: University of New Brunswick, Canadian Forest Service, Agriculture and Agri-Food Canada (AAFC)

Journal: Insect Conservation and Diversity
Location: Sierra Chincua and Cerro Pelon, Mexico

Monarch butterflies overwinter in the Sierra Chincua and Cerro Pelon, Mexico, for a period of 154 days. During this time, they cluster on oyamel fir trees, which are on average 1.4 °C warmer than surrounding temperatures at night (protecting from freezing) and 1.2 °C cooler during the day (slowing the loss of fat stores). Older trees (with wider trunks) had more beneficial microclimates.

Monarch Butterfly – Danaus plexippus
Oyamel Fir – Abies religiosa

Brower LP, Williams EH, Slayback DA, Fink LS, Ramirez MI, Zubieta RR, Garcia MIL, Gier P, Lear JA, van Hook T, 2009. “Oyamel fir forest trunks provide thermal advantages for overwintering monarch butterflies in Mexico.” Insect Conservation and Diversity, DOI: 10.1111/j.1752-4598.2009.00052.x
Affiliations: Sweet Briar College, VA; Hamilton College, NY; NASA Goddard Space Flight Center; Universidad Nacional Autonoma de Mexico (UNAM); Huntingdon College, AL; National Cathedral School, Washington, DC.

Journal: African Journal of Ecology
Location: Uganda

Blue Gum Chalcids are highly invasive gall-forming wasps that attack eucalypts. In Uganda, there was no infestation found at high altitudes from 1938 to 2452m (the highest tested) above sea level, which includes the range of Maiden’s Gum.

Blue Gum Chalcid – Leptocybe invasa
Maiden’s Gum – Eucalyptus globulus ssp maidenii

Nyeko P, Mutitu EK, Day RK, 2009. “Eucalyptus infestation by Leptocybe invasa in Uganda.” African Journal of Ecology, DOI: 10.1111/j.1365-2028.2008.01004.x
Affiliations: Makerere University, KEFRI (Kenya Forestry Research Institute), CABI (Commonwealth Agricultural Bureaux International)

Journal: Basic and Applied Ecology
Location: Hainich, Germany

In Hainich National Park, and old-growth forest in Germany, leaves in the upper canopy of eight tree species varied in size from 12.9 to 19.4 m2 per kg, were covered in 125 to 313 stomata per mm, contained 95-175mol Nitrogen per m2, and had a delta 13C value (the degree of carbon enrichment compared to inorganic matter, the more negative the higher), of -27.81 to -25.85 parts per thousand (typical of C3 photosynthesis). Sycamore, Hornbeam, Ash, and Linden saplings had a maximum CO2 assimilation rate (Amax, indicating photosynthetic rate) of 5.0 and 6.4 mumol m–2s–1. Adult Hornbeams had the lowest Amax (10.5), and Ash the highest (16.3). Lower canopy Ash also had the highest Amax (12.0, compared to 5.0-5.6).

Sycamore – Acer pseudoplatanus
Hornbeam – Carpinus betulus
Ash – Fraxinus Excelsior
Linden – Tilia platyphyllos

Hölscher D, 2004. “Leaf traits and photosynthetic parameters of saplings and adult trees of co-existing species in a temperate broad-leaved forest.” Basic and Applied Ecology, 5(2): 163-172, DOI: 10.1078/1439-1791-00218
Affiliations: University of Göttingen

Journal: Basic and Applied Ecology
Location: Boreal Sweden

In 30 managed forests (180ha in total) in boreal Sweden surveyed before harvest, 33 red list bryophyte and lichen species (35% of all red list species that have been observed in that part of Sweden) were found, ranging from 5 to 16 species per stand (10 on average), or 6 per hectare. This is more frequent than in designated hot-spot areas. 51% of species were growing on dead trees, and 48% on live. Mature managed forests may be important habitats for red list bryophyte and lichen species.

Gustafsson L, Appelgren L, Jonsson F, Nordin U, Persson AA, Weslien J-O, 2004. “High occurrence of red-listed bryophytes and lichens in mature managed forests in boreal Sweden” Basic and Applied Ecology, Volume 5(2): 123-129, DOI: 10.1078/1439-1791-00223.
Affiliations: Swedish University of Agricultural Sciences, Vänersborg, Trångsviken, The Forestry Research Institute of Sweden (Skogforsk)

McPherson E.G., Simpson J.R., 2003 “Potential energy savings in buildings by an urban tree planting programme in California” Urban Forestry & Urban Greening, 2(2): 73-86(14), DOI: 10.1078/1618-8667-00025
USDA Forest Service, Pacific Southwest Research Station, Davis, CA
Location: California, USA

The ~177.3 million energy-conserving trees in California should reduce the amount of energy used for air conditioning by in a single year by 2.5% (saving US$485.8 million), and save utilities 10% (US$778.5 million) annually. If 50 million trees were planted, over a 15-year period each tree would save US$71, while the cost of planting and protecting each tree is only US$50.

Johnson A.D., Gerhold H.D. 2003 “Carbon storage by urban tree cultivars, in roots and above-ground”, Urban Forestry & Urban Greening, 2(2): 65-72(8), DOI: 10.1078/1618-8667-00024
Southern University and A&M College – CAFCS, LA
Pennsylvania State University, PA
Location: ?, USA

The average amount of carbon stored in nursery or recently transplanted Juneberry, Apple, Pear, and Lilac cultivars was measured. Smaller trees (3.8-6.4 cm diameter at breast height) stored 0.3-1.0 kg carbon in the roots, and 1.7-3.6 kg in total. Larger trees (14.0-19.7 cm dbh) stored 10.4 kg+ in the roots, and 54.5 kg in total.

Juneberry – Amelenchier spp.
Apple – Malus spp.
Pear – Pyrus spp.
Lilac – Syringa spp.

Nowak D.J., Kuroda M., Crane D.E. 2004 “Tree mortality rates and tree population projections in Baltimore, Maryland, USA” Urban Forestry & Urban Greening 2(3): 139-147(9), DOI: 10.1078/1618-8667-00030
USDA Forest Service, Northeastern Research Station, NY
SUNY College of Environmental Science and Forestry, NY
Location: Baltimore, Maryland, USA

In Baltimore, 6.6% of trees die annually, with an annual decrease in the number of trees of 4.2%. Particularly high mortality rates are seen on sites used for transportation, and commercial and industrial areas, whereas residential areas have relatively few tree deaths. Urban forestry in Baltimore is projected to decline.

Solfjeld I., Hansen O.B. 2004 “Post-transplant growth of five deciduous ordic tree species as affected by transplanting date and root pruning” Urban Forestry & Urban Greening, 2(3): 129-137(9), DOI: 10.1078/1618-8667-00029
Department of Plant and Environmental Sciences, Agricultural University of Norway
Location: Norway

Transplanting was followed by a reduction in growth in four deciduous tree species in Norway, but not in Rowan. After one season, Norway Maple, Horse Chestnut, Wild Cherry and and Common Lime ‘Pallida’ had shoot growth reduced by 38-86%, and leaf surface area by 13-61%. In the second season, shoot growth was reduced in Norway Maple by 71% and by 81% in Horse Chestnut, which did not return to normal growth in the third season.

Common Lime ‘Pallida’ – Tilia x europaea L. ‘Pallida’
Horse Chestnut – Aesculus hippocastanum L.
Norway Maple – Acer platanoides L.
Rowan – Sorbus aucuparia L.
Wild Cherry – Prunus avium L.