Paul Henning Krogh

Nuuk Basic: BioBasis programme

Publication: ResearchReport chapter

Results of the seventh year of the BioBasis monitoring programme at Nuuk arepresented.
Reproductive phenology: In L. procumbens and S. acaulis vegetative phenology is similar to that of 2012, although there was a tendency to produce larger numbers of flowers in most plots. The timing of 50 % flowering was within the same range as previous years. The flower bud production, the onset of flowering, and the peak flower production of L. procumbens occurred at approximately the same timeas in 2012. A second bud production was recorded 3 September Day of Year (DOY) 246. All plots produced more flowers in 2013 than in 2012. The first senescent flowers were recorded about the same time as in 2012. Timing of budding, flowering and senescence in S. acaulis was later thanin 2012. S. glauca buds were observed aweek later compared to the earliest year 2010. First flowering male catkins were observed 13 June (DOY 164) and first female catkins 18 June (DOY 169). The first female flowers with hair were observed 11 July. A higher number of flowers were produced in 2013 than in 2012. During April the area was exposed to two weeks of severe snowmelt, followed by heavy snowfall in May, resulting in late snowmelt. A preliminary review of data related to flowering indicates that 2013 was characterized by no larval outbreak of the noctuid moth E. occulta, and large numbers of flowers produced in L. procumbens and S. glauca compared to 2012.
Vegetation greening: Empetrum nigrum reached the highest Normalised Difference Vegetation Index (NDVI) values of all the species, and NDVI was consistently high throughout the season. The values were at the same level or higher than in 2012, which was the highest recorded so far. Generally, the vegetation greening in 2013 was very similar to that in 2012. The NDVI values were in many cases higher throughout the season compared to previous years, with an intermediate to late peak. The vegetation seems to have recovered after the outbreak of the noctuid moth larvae.
Carbon dioxide exchange: Since 2008 carbon dioxide exchange has been measured including manipulation experiments simulating higher temperatures and increased cloud cover. Generally, all plots functioned as sinks for atmospheric CO2 at the time of the measurement (midday). In October, Net Ecosystem Exchange (NEE) was generally close to zero. Similar to previous years the uptake of CO2 was higher in control plots compared to plots with elevated temperature and shaded plots. The differences between treatments during 2013 were in general similar to previous years. Together with 2012, the flux amplitudes in 2013 were higher compared with previous years.
UV-B exclusion plots: Measurements of chlorophyll fluorescence as a proxy forplant stress were carried out. The total performance index (PItotal) integrates the measurements, and the PItotal were sensitive to UV-B exclusion in both V.uliginosum and B. nana. The seasonal plant stress level was reduced when the plants were protected from UV-B radiation.
Arthropods: Pitfall traps were established from 28 May (DOY 148) through 13 June (DOY 164) and they all worked continuously until 7 October (DOY 280) when the liquid began to freeze. In 2013, arthropods were caught during 4511 trapdays (including 4057 pitfall-trap daysand 454 window-trap days). Parts of the samples are being sorted at Department of Bioscience, Aarhus University, Denmark. The material sampled in the 2013 season is currently stored in 70 % ethanol at Greenland Institute of Natural Resources.
Microarthropods: In the season 2013, the sampling of microarthropods was reduced from the standard of eight samples per plot to four samples per plot. Sampling was carried out three times during the season. The samples have not been analysed yet. The material sampled and extracted is currently stored in 70 %ethanol at the Greenland Institute of Natural Resources. Materials collected from research projects completed in 2012 in Kobbefjord and Zackenberg were further analysed. For project description andresults see chapter 6.
Birds: No survey of breeding passerines was carried out in 2013. A breeding pair of white-tailed eagles Haliaeetus albicilla was observed on the mountain side northeast of the research house in Kobbefjord. All four species of passerines (Lapland buntings, snow buntings, northern wheatears, and redpolls) were already present at the time of the first census, and the survey was carried out until no more observations were made at any census point. The total number of passerines has varied between the years. In 2013, the northern wheatear was the most abundantly observed passerine, and the only species to have more observations per census in 2013 than in 2012. Although there is some variance from year to year, the number of observations of northern wheatears is usually at its maximum in August.
Mammals: The Kobbefjord catchment area is only  sparsely populated with mammals. In 2013, at least two different foxes have been observed on several occasions; tracks, faeces and barks have been observed/heard throughout the season. One Arctic hare was observed.
Lakes: 2013 was relatively wet, particularly during the winter period. It was the coldest summer registered during the monitored period and the ice-free period lasted less than 132 days in Badesø and less than 124 in Qassi-sø. Average total nitrogen concentration in both lakes was the lowest measured and average total
phosphorus was generally low in Badesø. During the last three years, chlorophyll
a has stabilized around 0.8 μg Chl a l-1, following an increasing trend during the
2008-2010 period. Zooplankton biomass is generally higher in Qassi-sø compared to Badesø, which is consistent with the lack of fi sh in Qassi-sø. During the past three years an increasing zooplankton biomass is observed in Badesø; this can partly be due to reduced predation pressure, corresponding well with reduced fi sh abundance in 2013 compared to 2008, when the first fish investigation was undertaken.
Original languageEnglish
Title of host publicationNuuk Ecological Research Operations : 7th Annual Report 2013
EditorsLillian Magelund Jensen, Torben Røjle Christensen
Number of pages12
PublisherAarhus University, DCE - Danish Centre for Environment and Energy
Publication year2014
ISBN (electronic)978-87-93129-21-4
StatePublished - 2014

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