Ecosystem functions
At the time of harvest (80 days after planting) a total of 10 responses
were measured that reflect plant and soil functioning of efficient
nutrient cycling and enhanced plant performance: four soil enzyme
activities 1) cellobiohydrolase (CBH), 2) β-1,4-glucosidase (βG), 3)
β-1,4-N-acetylglucosaminidase (NAG), and 4) alkaline phosphatase (ALP).
CBH and βG are related to soil carbon that contribute to the degradation
of cellulose (Ljungdahl and Eriksson, 1985). NAG contributes to the
degradation of chitin and plays a role in soil nitrogen cycling
(Sinsabaugh et al., 2008). ALP can release soil phosphate, and related
to AMF phosphorus uptake and transport (Larsen et al., 1996; Turner et
al., 2002). Two greenhouse gases emission, 5) CH4 and 6)
N2O that are two potent long-lived greenhouse gases (Mar
et al., 2022; Thompson et al., 2019). We included four soil and plant
responses indicating plant nutrient use efficiency which were 7) soil
NO3--N and 8) soil
NH4+-N contents, 9) net photosynthetic
rate, which represents the carbon fixation capacity of the ecosystem and
is the basis of primary productivity and 10) above-ground biomass, an
important indicator to reflect primary production (Garland et al.,
2021). In our study, higher emissions of N2O and
CH4 from the soil were considered negative because they
indicate a greater greenhouse effect and more soil nutrient loss.
Similarly, higher residual plant-available soil NO₃⁻-N and NH₄⁺-N were
considered dysfunctional, as they indicate less efficient nitrogen use.
Therefore, these four values were inverted by 1-x. We calculated
ecosystem multifunctionality using the average method (Maestre et al.,
2012; Xu et al., 2024). This was done by the
‘getStdAndMeanFunctions ’ function in R package ‘multifunc’
(Byrnes et al., 2014).