Login | Datasets | Logout
 

Comprehensive View of a Plot

  click to update datacart
085-JGNF-0002
» Citation URL: http://vegbank.org/cite/urn:lsid:cvs.bio.unc.edu:observation:14348-{B4B8318B-83B7-4CB9-941E-F410949DF6CD}
» Citing info
Plot ID Fields: 
Author Plot Code ? 085-JGNF-0002
Author Observation Code ? 085-JGNF-0002
Location Fields: MAP: Google | Yahoo | TopoZone | MapQuest
Location Accuracy ? 100 m
Confidentiality Status ? 100 km radius (nearest degree)
Latitude ? 38 º
Longitude ? -80 º
State or Province ? Virginia
Named Places
county: Rockbridge
region|state|province: Virginia
Layout Fields: 
DSG Polygon ? 20 x 50 m
Area ? 1000
Permanence ? not permanent
Environment Fields: 
Elevation ? 552 m
Slope Aspect ? 0 º
Slope Gradient ? 24 º
Topographic Position ? lower slope
Landform ? cove
Hydrologic Regime ? terrestrial (upland)
Soil Moisture Regime ? submesic
Soil Drainage ? well drained
Methods Fields: 
Observation Start Date ? 16-Aug-2000
Observation End Date ? 16-Aug-2000
Project ? Virginia Heritage
Cover Method ? Carolina Vegetation Survey
Stratum Method ? No Strata
Method Narrative ? Releve Virginia Division of Natural Heritage, see http://www.dcr.virginia.gov/natural_heritage/documents/nh_plotform_instructions.pdf
Overall Taxon Cover Values are Automatically Calculated? ? no
Stem Observation Area ? 1000
Plot Quality Fields: 
Plot Validation Level ? (2) classification plot: sufficient for inclusion in a classification revision
Overall Plot Vegetation Fields: 
Tree Height ? 30 m
Field Height ? 1 m
Tree Cover ? 70 %
Shrub Cover ? 20 %
Field Cover ? 10 %
Nonvascular Cover ? 5 %
Misc Fields: 
Observation Narrative ? Plot was sampled with the intent of capturing several characteristic species of southern Appalachian acidic cove and slope forests -- Galax urceolata, Oxydendrum arboreum, and Vaccinium erythrocarpum -- which are virtually absent from the Blue Ridge north of the James or Roanoke Rivers, but which range farther north in the Ridge and Valley. Rhododendron maximum, however, is missing from this lower slope, which supports an interrupted shrub layer of R. catawbiense and Kalmia latifolia; the density of these two species is highest in the residual modules, especially 5, 6 and 7. Module 1 is very open, with dense ground cover of V. erythrocarpum and Menziesia pilosa seedlings 10-20 cm tall. Galax is restricted in the plot to small, scattered patches, but is much more abundant along North Buffalo Creek below the plot. Two large Quercus coccinea snags in modules 9 and 10 created a gap measuring ca. 50 sq. m and spanning modules 1, 2, 9 and 10. Plot crosses small boulderfield in modules 3 and 8. Coarse woody debris abounds and several small snags are present, but there is no evidence of recent stand-level disturbance.
Taxa occurring on this plot-observation
Change plant label:
Change Strata Shown:
ord Author Plant Name ?Original Interpretation, full Scientific Name ?Original Interpretation, Scientific Name without authors ?Original Interpretation, Common Name ?Original Interpretation, USDA Code ?Current Interpretation, full Scientific Name ?Current Interpretation, Scientific Name without authors ?Current Interpretation, Common Name ?Current Interpretation, USDA Code ? Stratum ?Cover ?Original Cover Code ?Basal Area ?Biomass ?Inference Area ? Stems: Stem Diameters (graphically):
1 Kalmia latifolia Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   Kalmia latifolia **   -all-  
17.5 %
6      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     40 stem(s)
1.75 cm ± 0.75 cm     12 stem(s)
3.75 cm ± 1.25 cm     1 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem
2 Oxydendrum arboreum Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   Oxydendrum arboreum **   -all-  
17.5 %
6      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
1.75 cm ± 0.75 cm     2 stem(s)
7.5 cm ± 2.5 cm     1 stem(s)
12.5 cm ± 2.5 cm     2 stem(s)
17.5 cm ± 2.5 cm     3 stem(s)
22.5 cm ± 2.5 cm     2 stem(s)
27.5 cm ± 2.5 cm     2 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem
3 Betula lenta var. lenta Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   Betula lenta var. lenta **   -all-  
17.5 %
6      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     1 stem(s)
1.75 cm ± 0.75 cm     1 stem(s)
3.75 cm ± 1.25 cm     5 stem(s)
7.5 cm ± 2.5 cm     5 stem(s)
12.5 cm ± 2.5 cm     7 stem(s)
17.5 cm ± 2.5 cm     2 stem(s)
22.5 cm ± 2.5 cm     1 stem(s)
37.5 cm ± 2.5 cm     2 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem
4 Quercus montana Quercus montana **   Quercus montana **   Quercus montana **   Quercus montana **   Quercus montana **   Quercus montana **   Quercus montana **   Quercus montana **   -all-  
17.5 %
6      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
17.5 cm ± 2.5 cm     2 stem(s)
27.5 cm ± 2.5 cm     1 stem(s)
32.5 cm ± 2.5 cm     2 stem(s)
37.5 cm ± 2.5 cm     3 stem(s)
47.5 cm ± 0.5 cm     1 stem(s)
55.5 cm ± 0.5 cm     1 stem(s)
stem stem stem stem stem stem stem stem stem stem
5 Quercus coccinea Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   Quercus coccinea **   -all-  
17.5 %
6      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
27.5 cm ± 2.5 cm     1 stem(s)
32.5 cm ± 2.5 cm     1 stem(s)
37.5 cm ± 2.5 cm     2 stem(s)
44.5 cm ± 0.5 cm     1 stem(s)
stem stem stem stem stem
6 Rhododendron catawbiense Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   Rhododendron catawbiense **   -all-  
7.5 %
5      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     24 stem(s)
1.75 cm ± 0.75 cm     70 stem(s)
3.75 cm ± 1.25 cm     19 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem
7 Acer rubrum Acer rubrum **   Acer rubrum **   Acer rubrum **   Acer rubrum **   Acer rubrum **   Acer rubrum **   Acer rubrum **   Acer rubrum **   -all-  
7.5 %
5      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     3 stem(s)
1.75 cm ± 0.75 cm     9 stem(s)
3.75 cm ± 1.25 cm     8 stem(s)
7.5 cm ± 2.5 cm     6 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem
8 Nyssa sylvatica Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   Nyssa sylvatica **   -all-  
3.5 %
4      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
1.75 cm ± 0.75 cm     1 stem(s)
17.5 cm ± 2.5 cm     1 stem(s)
27.5 cm ± 2.5 cm     1 stem(s)
32.5 cm ± 2.5 cm     1 stem(s)
stem stem stem stem
9 Amelanchier arborea Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   Amelanchier arborea **   -all-  
3.5 %
4      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     1 stem(s)
12.5 cm ± 2.5 cm     1 stem(s)
stem stem
10 Quercus alba Quercus alba **   Quercus alba **   Quercus alba **   Quercus alba **   Quercus alba **   Quercus alba **   Quercus alba **   Quercus alba **   -all-  
1.5 %
3      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
37.5 cm ± 2.5 cm     1 stem(s)
stem
11 Magnolia acuminata Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   Magnolia acuminata **   -all-  
1.5 %
3      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
27.5 cm ± 2.5 cm     1 stem(s)
stem
12 Acer pensylvanicum Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   Acer pensylvanicum **   -all-  
1.5 %
3      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     17 stem(s)
1.75 cm ± 0.75 cm     14 stem(s)
3.75 cm ± 1.25 cm     10 stem(s)
7.5 cm ± 2.5 cm     4 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem stem
13 Menziesia pilosa Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   Menziesia pilosa **   -all-  
1.5 %
3       -none-
14 Tsuga canadensis Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   Tsuga canadensis **   -all-  
1.5 %
3      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     5 stem(s)
1.75 cm ± 0.75 cm     2 stem(s)
3.75 cm ± 1.25 cm     2 stem(s)
7.5 cm ± 2.5 cm     3 stem(s)
17.5 cm ± 2.5 cm     1 stem(s)
stem stem stem stem stem stem stem stem stem stem stem stem stem
15 Viburnum acerifolium Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   Viburnum acerifolium **   -all-  
0.505 %
2       -none-
16 Mitchella repens Mitchella repens **   Mitchella repens **   Mitchella repens **   Mitchella repens **   Mitchella repens **   Mitchella repens **   Mitchella repens **   Mitchella repens **   -all-  
0.505 %
2       -none-
17 Vaccinium pallidum Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   Vaccinium pallidum **   -all-  
0.505 %
2       -none-
18 Viola sororia Viola sororia **   Viola sororia **   Viola sororia **   Viola sororia **   Viola sororia **   Viola sororia **   Viola sororia **   Viola sororia **   -all-  
0.505 %
2       -none-
19 Castanea dentata Castanea dentata **   Castanea dentata **   Castanea dentata **   Castanea dentata **   Castanea dentata **   Castanea dentata **   Castanea dentata **   Castanea dentata **   -all-  
0.505 %
2      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
1.75 cm ± 0.75 cm     1 stem(s)
stem
20 Parthenocissus quinquefolia Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   Parthenocissus quinquefolia **   -all-  
0.505 %
2       -none-
21 Uvularia puberula Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   Uvularia puberula **   -all-  
0.505 %
2       -none-
22 Hamamelis virginiana var. virginiana Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   Hamamelis virginiana var. virginiana **   -all-  
0.505 %
2      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     5 stem(s)
stem stem stem stem stem
23 Vaccinium erythrocarpum Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   Vaccinium erythrocarpum **   -all-  
0.505 %
2       -none-
24 Galax urceolata Galax urceolata **   Galax urceolata **   Galax urceolata **   Galax urceolata **   Galax urceolata **   Galax urceolata **   Galax urceolata **   Galax urceolata **   -all-  
0.505 %
2       -none-
25 Dioscorea quaternata Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   Dioscorea quaternata **   -all-  
0.505 %
2       -none-
26 Smilax rotundifolia Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   Smilax rotundifolia **   -all-  
0.505 %
2      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     1 stem(s)
stem
27 Pinus strobus Pinus strobus **   Pinus strobus **   Pinus strobus **   Pinus strobus **   Pinus strobus **   Pinus strobus **   Pinus strobus **   Pinus strobus **   -all-  
0.505 %
2       -none-
28 Polypodium appalachianum Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   Polypodium appalachianum **   -all-  
0.505 %
2       -none-
29 Goodyera pubescens Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   Goodyera pubescens **   -all-  
0.505 %
2       -none-
30 Gaultheria procumbens Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   Gaultheria procumbens **   -all-  
0.505 %
2       -none-
31 Ilex montana Ilex montana **   Ilex montana **   Ilex montana **   Ilex montana **   Ilex montana **   Ilex montana **   Ilex montana **   Ilex montana **   -all-  
0.505 %
2      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
0.5 cm ± 0.5 cm     1 stem(s)
1.75 cm ± 0.75 cm     2 stem(s)
stem stem stem
32 Dryopteris marginalis Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   Dryopteris marginalis **   -all-  
0.05 %
1       -none-
33 Gillenia trifoliata Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   Gillenia trifoliata **   -all-  
0.05 %
1       -none-
34 Spiraea corymbosa Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   Spiraea corymbosa **   -all-  
0.05 %
1       -none-
35 Liriodendron tulipifera Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   Liriodendron tulipifera **   -all-  
0.05 %
1      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
41.5 cm ± 0.5 cm     1 stem(s)
44.5 cm ± 0.5 cm     1 stem(s)
stem stem
36 Medeola virginiana Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   Medeola virginiana **   -all-  
0.05 %
1       -none-
37 Chimaphila maculata Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   Chimaphila maculata **   -all-  
0.05 %
1       -none-
38 Quercus rubra Quercus rubra **   Quercus rubra **   Quercus rubra **   Quercus rubra **   Quercus rubra **   Quercus rubra **   Quercus rubra **   Quercus rubra **   -all-  
0.05 %
1      
DBH ?DBH err ?Ht. ?Ht. Err ?# ?
17.5 cm ± 2.5 cm     1 stem(s)
stem
39 Polygonatum biflorum Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   Polygonatum biflorum **   -all-  
0.05 %
1       -none-
40 Crataegus sp. Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   Crataegus sp. **   -all-  
0.05 %
1       -none-
41 Carya glabra Carya glabra **   Carya glabra **   Carya glabra **   Carya glabra **   Carya glabra **   Carya glabra **   Carya glabra **   Carya glabra **   -all-  
0.05 %
1       -none-
42 Quercus velutina Quercus velutina **   Quercus velutina **   Quercus velutina **   Quercus velutina **   Quercus velutina **   Quercus velutina **   Quercus velutina **   Quercus velutina **   -all-  
0.05 %
1       -none-
43 Aralia nudicaulis Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   Aralia nudicaulis **   -all-  
0.05 %
1       -none-
44 Chamaelirium luteum Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   Chamaelirium luteum **   -all-  
0.05 %
1       -none-
45 Monotropa uniflora Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   Monotropa uniflora **   -all-  
0.05 %
1       -none-
46 Eurybia divaricata Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   Eurybia divaricata **   -all-  
0.05 %
1       -none-
47 Smilax glauca Smilax glauca **   Smilax glauca **   Smilax glauca **   Smilax glauca **   Smilax glauca **   Smilax glauca **   Smilax glauca **   Smilax glauca **   -all-  
0.05 %
1       -none-
48 Sassafras albidum Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   Sassafras albidum **   -all-  
0.05 %
1       -none-
49 Epigaea repens Epigaea repens **   Epigaea repens **   Epigaea repens **   Epigaea repens **   Epigaea repens **   Epigaea repens **   Epigaea repens **   Epigaea repens **   -all-  
0.05 %
1       -none-
This table is SORTABLE. Click the headers to sort ascending and descending.

Stratum Definitions:
Sorry, no Stratum Definitions found.
This table is SORTABLE. Click the headers to sort ascending and descending.
Observation Contributors:
Party ?Role ?
Coulling, Philip Author
Community Classification:
More Classification Start Date ? Community AssignmentsContributors
Details 28-Feb-2001
Community Concept ?Class Fit ?Class Confidence ?Community Authority Reference ?Typal ?
Liriodendron tulipifera - Quercus montana - (Tsuga canadensis) / Kalmia latifolia - (Rhododendron catawbiense) Forest 5 High   no
No Class Contributors.


Soil Observations:
Soil Horizon ?Soil Depth Top ?Soil Depth Bottom ?Soil Color ?Soil Organic ?Soil Texture ?Soil Sand ?Soil Silt ?Soil Clay ?Soil Coarse ?Soil PH ?Exchange Capacity ?Base Saturation ?Soil Description ?
unknown       7.6100001335144 %           3.79999995231628 14.960000038147 15.5200004577637 % 0 - 1 - litter and duff 1 - 4 - O horizon: dark brown 4 - light gray to light brown, cobbly, fine sandy loam; sample from module 9 is considerably sandier and less rocky


User Defined Values
No User Defined Data for this plot