As part of a project to restore species-rich grasslands on ex-arable land, robust Tinytag data loggers record soil temperature and RH to help understand planting and growing conditions. The loggers provide patterns of temperature and humidity data to help optimise seed germination.
Restoration of species-rich grasslands, that
are of high value because of the diverse flora and fauna that they
support, is part of the UK's strategy to preserve its native
biodiversity. The NERC Centre for Ecology & Hydrology
(CEH) worked in a project to test new methods to restore
such types of grassland at sites where they have disappeared due to
agricultural intensification. Understanding what goes on at grass
roots level with regard to abiotic conditions such as temperature and
humidity is an important part of the process.
192 Tinytag data loggers have been used for
this purpose at the Pegsdon Hills Nature Reserve
in the Chilterns from the summer of 2008.
Intensive arable farming and intensified grassland
management in the UK have resulted in the loss and fragmentation of
high quality, species-rich grasslands. A small number of
high yielding grasses that are better adapted to the conditions of
high fertility generated by intensive agriculture arable farming,
have displaced wild flowers and herbaceous flowering plants (known
as 'forbs'), such as rock rose, milk-wort and wild thyme.
The NERC Centre for Ecology & Hydrology is
looking at better ways to establish such species-rich
grasslands at existing agriculturally improved restoration
sites. Such sites often experience seed regeneration
difficulties, as many forb species are quite rare these days and
restricted to a few remaining sites less affected by agricultural
intensification, and thus generally do not naturally colonise
restoration sites. Typically the sites are chalk grassland. A
second focus of the project is to establish management
regimes to prevent high yielding 'scrub' grasses out-competing wild
flower species after they have been introduced from seed
or via pre-grown 'plug' plants.
The data loggers have been deployed 3 times a year, in
spring, summer and autumn, for one week at a time. The
loggers have monitored factors that are known to affect plant
establishment. Temperature and
humidity data has been recorded at surface level, and temperature also in top
10cm of the soil profile. These factors are important for at
least two reasons: first, the seeds of many species possess inbuilt
mechanisms to time germination in response to fluctuations in light
and moisture levels. Too little fluctuation indicates too much
overlying dense vegetation, cutting light and taking moisture,
which would prevent new establishment from seed.
Seed germination in these species therefore only takes place
when there is sufficient fluctuation, indicating favourable
conditions for establishment. Second, the tiny seedling stage of a
plant is the stage most vulnerable to extremes in abiotic factors
such moisture, and getting these factors right is of crucial
importance for successful re-introduction of rare forb species.
Dr Markus Wagner is a Grassland Ecologist and
team co-ordinator of the project. He comments: "The
Tinytag data loggers have proved reliable, sturdy and easy to use.
They have provided us with patterns of temperature and humidity
data that we can relate to what we already know about seed
germination in these conditions and that help us with the
interpretation of the results of our study. Optimising methods of
re-introduction offers us a better chance of maximising
establishment from seed which is often hard to come by due to a
lack of suitable 'donor' sites that can be used for seed
The data can be downloaded onsite but in this case is downloaded
at the research centre using Tinytag Explorer Software.
The project, funded by DEFRA, will continue to
refine methods for restoring species-rich grassland, meeting the
Government's biodiversity strategy but perhaps, more importantly,
helping to preserve a countryside rich with flora and fauna.
The Centre for Ecology & Hydrology (CEH) is
the UK's centre of excellence for research in land and freshwater
environmental sciences. Their work encompasses a wide range of
environmental disciplines ranging from the smallest genes to whole
Photo: C. Lamberth