Table 2. Summary of harvester and scientific knowledge about mistletoe ecology and distribution and the effects of mistletoe infection on amla.
Characteristic TEK† Data type Ecological studies Concordance
Primary host P. emblica, P. indofischeri Qualitative 82% of mistletoes sampled observed on P. emblica and P. indofischeri (Rist et al. 2008b) Excellent
Secondary host 35 species Quantitative 12 species (Rist et al. 2008b) Some
Infection prevalence 0.5–0.8 (mean = 0.57 ± 0.11)‡ Quantitative 0.51 (Rist et al. 2008b) Excellent
P. emblica vs. P. indofischeri infection P. emblica is more commonly infected; older, taller trees are more often infected and have more mistletoes Qualitative Prevalence 0.64 in P. emblica and 0.38 in P. indofischeri (Rist et al. 2008b); greater probability and intensity of infection in taller trees (Rist et al. 2008b) Excellent
Forest type Deciduous forest, i.e., moist, dense forest and hill tops Qualitative Deciduous forest (Rist et al. 2008b) Excellent
Phenology Flowers during summer; fruits at end of summer prior to rains Qualitative Peak flowering: April–July (summer); peak fruiting: August–November (rains in July/August; Rist 2008) Excellent
Flower visitors Flowerpeckers, sunbirds, insects Qualitative Flowerpeckers (Davidar 1983); lorikeet, drongo (Shrestha 2000) Some
Dispersal Birds, squirrels, bats, rats, monkeys, and wind Qualitative Flowerpeckers (Davidar 1978), bulbuls (Ali and Ripley 1983, Shrestha 2000) Poor
Favorable conditions for mistletoe growth Moist, dense forest Qualitative High moisture (Reid and Lange 1988), high light levels (Norton and Reid 1997) Good
Effects on growth Reduces growth Qualitative Significantly reduces growth (Setty 2004) Good
Effects on productivity 25–100% reduction in fruit production (mean = 68 ± 20.7%)§ Quantitative ~44% decrease (Setty 2004)§ Good
Effects on survival All infected trees die; mortality occurs 2–10 yr following infection Quantitative 54% mortality rate of infected trees over 4 yr (Setty 2004) Good
Differential susceptibility P. indofischeri more susceptible than P. emblica Qualitative Effect on growth only in P. emblica; effect on productivity is greater in P. emblica (Sinha and Bawa 2000) Poor

†Traditional ecological knowledge.
‡Harvester estimates of the proportion of the amla population infected by mistletoes and the decline in production of the average infected tree.
§Calculated from mean fruit production figures in Setty (2004) for infected and uninfected trees (P. emblica only). No information was given on the infection levels in these trees.