Figure 1.
(a) Phylogenetic tree of Tibetan moth species from the family Noctuidae, inferred using neighbor-joining analysis of 320 COI DNA sequences.
Different colours represent different genera. (b) Plot of genetic distances showing the barcoding gap. Intraspecies in red, interspecies in blue. Fitted normal distribution curves are shown in red.
Figure 2.
Species diversities of Tibetan moth species (Noctuidae) for each community, calculated using different diversity indices.
(a) Shannon index; (b) Simpson index; (c) Brillouin index; (d) index; (e) Exponential Shannon index; (f) Transformed Simpson index.
Figure 3.
Rank-abundance curves of each community based on DNA barcoding (DB) with different reference database (a–c) or traditional morphology (TM) (d).
(a) DB-based rank-abundance curves for each community based on reference size of 10% (01 ref). (b) DB-based rank-abundance curves for each community based on a reference size of 30% (03 ref). (c) DB-based rank-abundance curves for each community based on a reference size of 50% (05 ref). (d) TM-based rank-abundance curves for each community.
Figure 4.
Correlations between species diversity and environmental factors.
(a) Significant correlation between species diversity and three environmental factors, including precipitation of driest month, precipitation of driest quarter, and precipitation of coldest quarter. (b) Distribution of sampling sites/communities along different environmental gradients, including radiation and rainfall. Clustering of seven communities based on PCA of 22 environmental factors. (c) Spatial distribution of species diversities between West and East regions. (d) Rank-abundance curves of West and East communities.
Figure 5.
Sampling sites in the Qinghai-Tibetan Plateau in China.
Samples were collected from seven locations from West to East in Tibet, representing different ecological conditions. RKZ - Shigatse, Gyantse - JZ, Lhasa - LS, Shannan - SN, Pagsum Co - BSC, Mainling - ML, and Bome - BM.
Figure 6.
Species identity inferred via DNA barcoding for a community with a Bayesian method.
(a) An ecological community with species. (b) Bayesian formula used to infer species membership for unknown samples. (c) DV-Curve approach to construct DV-Matrix for Bayesian inference. is the
th species in the community,
is an unknown sample with DNA sequenced,
is the probability of a sample belonging to
.
is the conditional probability of the unknown sample
belonging to
given that its DNA is sequenced.
is the probability of having DNA sequence of the unknown sample
given that DNA sequences of
are known.