1.2.1 History
Ecosystem history, which includes historical soil and land management (i.e. disturbance, grazing, harvests or harvest regime, nutrient input and contamination, species introductions or extinctions) gives crucial information as any such changes may have a knock-on effect on a range of responses (Sala et al., 2000; Kepfer-Rojas et al., 2015). Providing accurate details of the ecosystem history (e.g. the number and degree of prescribed burning, fertilisation schemes, timber volume removed or the quantity of grazing animals) can be useful when assessing the impacts of land-use history and comparing different sites. These historical factors may also affect the responses of ecosystems to future environmental manipulations, such as climate, nutrient, and land use (Luo & Chen, 2013; Domec et al., 2015; Kröel-Dulay et al., 2015; De Keersmaecker et al., 2016). Finally, ecosystem history can be of value if the ratio of C3 to C4 plants has changed, for example through crop rotations, as this allows for analyses of ecosystem processes that are based on stable isotopes without additional cost.
1.2.2 Location
Latitude and longitude coordinates should be given (e.g. via GPS), in addition to the resolution of the position (e.g. ±3 m). Coordinates can help with finding additional information about a study site, such as weather data from a nearby station, or remote sensing products. It is also common to give the name of the location of the study site, the region, and country or continent. Multiple locations can be shown on a map.
1.2.3 Elevation (metres above sea level), slope (degrees), and aspect (degrees)
Atmospheric pressure, temperature, and radiation (including UV-B) change consistently with increasing elevation, while many other factors such as precipitation and wind vary regionally along elevational gradients (Körner, 2007). Slope is helpful in explaining observations related to soil hydraulic properties as well as the radiative conditions. Both slope and aspect influence surface temperature and are useful to report on a hill and in mountains, where topography changes over short distances.
Elevation can be extracted from a GPS, and slope and aspect can easily be measured using a clinometer and compass, respectively. A number of free apps for these measurements are now available for smartphones. For slope, a long rigid plank can be placed on the ground and the clinometer sat flush on the plank in order to measure the slope. If the small-scale heterogeneity is high, a measuring post set to eye level > 10m away from the plot provides a more accurate measurement of the average slope. Aspect is measured using a compass, facing downslope. Note that these parameters can be measured on different spatial scales; plot, block, or site. At coarser scales, these parameters can be determined from reference map sources.
1.2.4 Climate data
Long-term climate data from each study site should be reported to enhance reproducibility (Morueta-Holme et al., 2018). Common variables are mean annual temperature and precipitation, seasonality, and length of the growing season. Mean annual temperature and precipitation may not be very informative whereas summer maximum, winter minimum temperature, and growing season length are more relevant. It is important to cite the source of the data, the time frame over which the data were collected, name of the location if the data were obtained by a weather station, and (if applicable) to explain any data processing (Morueta-Holme et al., 2018).
1.2.5 Vegetation and habitat type
The habitat type (e.g. forest, grassland, desert), dominant plant functional type (e.g. trees, graminoids, forbs, mosses), cover and height of the dominant vegetation layers (e.g. trees, shrubs, dwarf-shrubs, herbaceous, cryptogams), and vegetation type (using relevant national or international classification schemes) of the study site should be described. It is also common to list the dominant species, and some biodiversity or structural information such as species richness and/or evenness.
1.2.6 References
De Keersmaecker, W., Rooijen, N., Lhermitte, S., Tits, L., Schaminée, J., Coppin, P., … Somers, B. (2016). Species‐rich semi‐natural grasslands have a higher resistance but a lower resilience than intensively managed agricultural grasslands in response to climate anomalies. Journal of Applied Ecology, 53(2), 430–439.
Domec, J.-C., King, J. S., Ward, E., Christopher Oishi, A., Palmroth, S., Radecki, A., … Noormets, A. (2015). Conversion of natural forests to managed forest plantations decreases tree resistance to prolonged droughts. Forest Ecology and Management, 355, 58–71.
Kepfer-Rojas, S., Verheyen, K., Johannsen, V. K., & Schmidt, I. K. (2015). Indirect effects of land-use legacies determine tree colonization patterns in abandoned heathland. Applied Vegetation Science, 18(3), 456–466.
Körner, C. (2007). The use of ‘altitude’ in ecological research. Trends in Ecology & Evolution, 22(11), 569–574.
Kröel-Dulay, G., Ransijn, J., Schmidt, I. K., Beier, C., De Angelis, P., de Dato, G., … Peñuelas, J. (2015). Increased sensitivity to climate change in disturbed ecosystems. Nature Communications, 6, 6682.
Luo, Y., & Chen, H. Y. H. (2013). Observations from old forests underestimate climate change effects on tree mortality. Nature Communications, 4, 1655.
Morueta-Holme, N., Oldfather, M. F., Olliff-Yang, R. L., Weitz, A. P., Levine, C. R., Kling, M. M., … Ackerly, D. D. (2018). Best practices for reporting climate data in ecology. Nature Climate Change, 8(2), 92–94.
Sala, O. E., Chapin, F. S., Armesto, J. J., Berlow, E., Bloomfield, J., Dirzo, R., … Wall, D. H. (2000). Global biodiversity scenarios for the year 2100. Science, 287(5459), 1770–1774.