Category Archives: Ecology

Nitrogen fertilizers in boreal forests and their effects on plants and animals

Gardeners often apply extra fertilizer to their wild berry patches to increase yields in wild stands. This paper summarizes research on the effects of applying nitrogen fertilizer on large and small animals as well as plants. It is an interesting survey of forest systems and not just the wild berry we have in mind.

Influence of nitrogen fertilization on abundance and diversity of plants and animals in temperate and boreal forests

Thomas P. Sullivan, Druscilla Sullivan

Published on the web 26 July 2017.

Environmental Reviews,


Aerial and land-based applications of nitrogen-based fertilizers to enhance forest growth makes nutrients potentially available to all trees, plants, and wildlife in a given ecosystem, and therefore may have direct and indirect effects on wildlife and biodiversity. A scientific review of these potential effects was conducted with 106 published studies covering vascular and non-vascular plants, amphibians, birds, mammals, terrestrial invertebrates, and soil animals associated with fertilization in temperate and boreal forests, primarily in North America and Scandinavia. In terms of direct effects, amphibians and domestic mammals appear to be the most sensitive to urea used in fertilization programs. The avoidance behaviour and/or mortality of amphibians in laboratory studies was species-dependent. Ruminant animals, including wild ungulates, rapidly convert urea to ammonia and are susceptible to toxicity following ingestion of large amounts of urea. Feeding on urea pellets by small mammals or gallinaceous birds appears to be minimal as granules are unpalatable. In terms of indirect effects, the majority of responses of understory herbs to nitrogen fertilization showed an increase in abundance. Some shrubs in repeatedly fertilized stands eventually increased in abundance in long-term studies, whereas dwarf shrubs and abundance of bryophytes (mosses and terrestrial lichens) declined. In general, species richness and diversity of understory herbs and shrubs declined, or were unaffected, in fertilized stands. Response in abundance and species richness-diversity of vascular plants to a single application of nitrogen showed either an increase or no change. Repeated applications (2-5 and > 5) usually resulted in declines in these responses. Relative abundance of mule deer (Odocoileus Rafinesque spp.), moose (Alces alces L.), and hares (Lepus L. spp.), and forage quantity and quality were usually increased by fertilization. Small mammal species generally showed increases or no change in abundance; decreases may be related to fertilizer-induced changes in food sources. Forest fertilization may provide winter feeding habitat for coniferous foliage-gleaning insectivorous birds in some cases. Six species of forest grouse showed no response to fertilizer treatments. Responses of soil animals to nitrogen fertilization appeared to be species- and dose-specific and ameliorated by surrounding micro- and macro-habitat characteristics.


Documenting Change in Nunavut

Here is a thesis that explores climate change through berries near Kugluktuk, Nunavut, Canada. The program is part citizen science as well as documenting the ethnobotany of the region. It includes great summaries of the most important berries and even some recipes!


Fall flowering in lingonberries

Occasionally, native plants, wildflowers, berries and others, bloom in fall. I have seen it on high bush cranberries, red osier dogwood, willows. wild iris, wild roses and more. This year it is lingonberries. I have noticed a lot of flowers appearing at the same time as berry harvesting. Considering the season, this second bloom is not surprising. Spring warm temperatures came early, and in my garden, Oct 1, the temperatures reached 60F! Despite the cool, rainy summer, the lingonberry grew, bloomed, matured fruit, and went dormant. The dormancy period is very short for lingonberries- about 4 weeks of chilling temperatures (40F or lower). With the long season, it is no surprise that flower buds broke dormancy and started to bloom again. Of course, it is wasted genes. No fruit will form. This fall flowering definitely impacts next season’s flowering and fruiting.


Phenology of Cloudberries and Lingonberries in Labrador

Here is a link to an article by Canadian Researchers who are interested in following the growth, flowering and fruiting of two of the most important wild berries, cloudberry and lingonberry. They followed phenological sequences of flowering and fruiting and documented potential pollinators in their region.  It is interesting to compare their cycles with Alaska. It was published in:

Canadian. Journal. of Plant Science. 96: 329–338 (2016)

Cloudberry and Lingon phenology

Abstract: Plant habitat, growth, fruit yield and occurrence of pollinators in cloudberry and lingonberry fields/bogs were monitored and analyzed at three locations in southern Labrador: Lanse’au Clair (51°41’ N, 57°08’ W), Red Bay (51°43’ N, 56°26’ W), and Cartwright (53°42’ N, 57°0’ W) over the two growing seasons, 2011 and 2012. The length of the growing seasons was 100–120 d (DFRA 2014) with 600–700 growing degree days (GDD) (AAFC 2014). The 2012 season was warmer than 2011. The plants recorded in belt transects belong to six families: Rosaceae, Ericaceae, Pottiaceae, Juncaeae, Equisetaceae, and Sphagnaceae. In the Ericaeae family, Vaccinium vitis-idaea, Arctostaphylos alpina, Empetrum nigrum, and Vaccinium angustifolium were found. In both seasons, the cloudberry was the first to bloom, followed by wild blueberry, lingonberry, and Labrador tea. The fruit yields of cloudberry and partridgeberry in southern Labrador were higher than those recorded in Finland, Norway, and in the USA. Pollinators were present in large numbers. Most of the specimens were from three orders: Hymenoptera, Diptera, and Lepidoptera. Temperature, precipitation, wind, and sunlight affected plant growth and the occurrence of pollinators. To our knowledge this is the most comprehensive study of plant growth, yield, and pollinators’ activity in cloudberry/partridgeberry fields conducted in Southern Labrador, Canada.