Seasonal changes in the understorey biomass of an oak-hornbeam forest Stellario holosteae-Carpinetum betuli

Abstract

Abstract. We studied seasonal changes in the understorey biomass of an oak-hornbeam forest association Stellario holosteae-Carpinetum betuli. Samples were collected weekly during the most active period of growth of the herbaceous layer (April-May 2010), and every two weeks for the remainder of the growing season (June-October). Quadrates of 0.36 m 2 were sampled from 7-9 randomly selected locations within the plant community. The plants harvested were separated by species, then oven-dried and weighed. We found statistically significant differences in aboveground understorey biomass over the periods of biomass harvesting. For example, the average plant biomass (produced in 2010 and previous years) was smallest on March 20 th (40.6 kg/ha), whereas the biomass was greatest on May 15 th (393.8 kg/ha). The mean biomass of the understorey vegetation during spring was 324.1 kg/ha, while the mean biomass for summer and early autumn was 108 kg/ha. The smallest plant biomass (produced during 2010) was on March 20 th (18.3 kg/ha) and the largest on May 15 th (378.4 kg/ha). Only a few herbaceous species dominated the total community biomass production. For example, from March 20 th to May 29 th the biomass of Anemone nemorosa was the highest at ca. 74% of total understorey herbaceous plant biomass, while Ficaria verna was second with 8%. During the next harvesting period (June-October) Galeobdolon luteum and Galium odoratum comprised 53.2% of total plant biomass harvested. It is evident that the highest biomass production is during the spring when the geophytes develop.

Seasonal Dynamics of Floodplain Forest Understory–Impacts of Degradation, Light Availability and Temperature on Biomass and Species Composition

“…For example, in Małopolska (S Poland), the maximum understory biomass in a Quercus-Carpinus-Tilia forest with geophytes reached up to 660 kg ha −1 , whereas in Fagus sylvatica forests without geophytes, it only reached 49 kg ha −1 [68]. This impact was also noted by other authors [27,28,41]. The impact of therophytes was connected mainly with the occurrence of invasive Impatiens parviflora, which is the most frequent alien species in European forests [69][70][71].…”

“…However, this resulted from high proportions of woody species in biomass in the cited study. Seasonal dynamics of biomass revealed by us resembled those of hardwood forests with Quercus robur, Carpinus betulus and Tilia cordata [27,28]. These dynamics were driven by both different dates of particular species emergence, as well as different seasonal dynamics of biomass production [26,30,41].…”

“…Our study revealed differences between study dates and study plots. Previous studies on dynamics of biomass production usually confirmed this effect [27,28], however, see [41] for an exception. In our study, the culmination of understory biomass crop lasted from the end of April to the end of June, despite compositional shifts.…”

“…Seasonality of deciduous forest ecosystems is connected with foliage fall during the autumn and its emergence during spring [24][25][26]. These dynamics imply taxonomic and functional diversity of dominants in understory biomass [26][27][28]. Seasonal dynamics are driven by changes in canopy openness, which allow development of spring ephemerals during an early spring period of high light availability, followed by decreasing light availability during late spring and summer [29,30].…”

Seasonal dynamics of shoot biomass of dominant clonal herb species in an oak–hornbeam forest herb layer

“…Stand species composition of well-preserved Stellario holosteae-Carpinetum betuli association (Rawlik et al 2012) is composed mostly of beech Fagus sylvatica (70%), hornbeam Carpinus betulus, oak Quercus robur, and sycamore Acer pseudoplatanus (Plan Urządzenia Lasu 2006). Additional description of the study site is given by Rawlik et al (2012). Mean annual temperature during 1971-2010 was 8.8°C and annual sum of precipitation was 541 mm.…”