The conflict between hosts and non-hosts changes the severity of diseases in degraded grassland plant communities

load: disease severity of plant community richnes: species richness Nonhost: Non-hosts richness coverage: relative coverage RHost: relative hosts richness PD: Faith's phylogenetic distance beta: beta diversity of plant community SLA: CWM SLA LN: CWM leaf N content LP:CWM leaf P content NP: CWM leaf N:P group: degree of grassland degradation Shannon: Shannon index of plant community Simpson: Simpsion index of plant community Pielou: Pielou index of plant community marglef: Marglef index of plant community