Problems with the RDA analysis

Hello everyone, I hope you are wonderful.

Does anyone know why in my RDA analysis, the last variable, which is precipitation, is not being contemplated, because in the analysis range I am contemplating it (Metadata[,7:19]).

Thanks in advance

# clear my environment
rm(list=ls()) 
#RDA

Familia <- tibble::tribble(
             ~SampleID, ~Cyanobacteriaceae, ~Microcystaceae, ~Nostocaceae,
                  "1A",        1.342953283,               0,            0,
                  "1C",        1.966304234,               0,            0,
                  "1D",                  0,               0,   1.80374141,
                  "1E",        1.492119211,               0,  1.492119211,
                  "1F",        0.597623166,               0,            0,
                  "1G",        1.319782597,               0,            0,
                  "1H",        0.859080227,      6.52598632,  0.859080227,
                  "2A",                  0,               0,  1.907218755,
                  "2B",        0.793958833,               0,            0,
                  "2C",                  0,     2.023336602,            0,
                  "2D",        0.859080227,               0,            0,
                  "2E",                  0,               0,  2.333056481,
                  "2F",                  0,     4.129704923,            0,
                  "2H",                  0,               0,  2.333056481,
                  "3A",                  0,               0,  2.970554964,
                  "3B",                  0,               0,  4.592839043,
                  "4A",                  0,               0,            0,
                  "4B",                  0,               0,            0,
                  "4E",                  0,               0,            0,
                  "4G",                  0,               0,            0,
                  "4H",                  0,     1.438454518,   3.33936827,
                  "5E",                  0,               0,            0,
                  "5F",                  0,     2.830692732,            0,
                  "5G",                  0,     2.063562226,            0,
                  "6A",                  0,               0,  2.333056481,
                  "6F",                  0,               0,            0,
                  "6H",                  0,     3.346178301,            0,
                  "7D",                  0,               0,            0,
                  "7F",                  0,     2.222744018,            0,
                  "7G",                  0,               0,            0,
                  "8A",                  0,               0,            0,
                  "8B",                  0,               0,            0,
                  "8C",                  0,               0,            0,
                  "8D",                  0,     2.830692732,            0,
                  "8E",                  0,               0,            0,
                  "8G",                  0,     3.025690271,  2.155958054,
                  "8H",                  0,     3.623754759,            0,
                  "9A",                  0,               0,   1.80374141,
                  "9B",                  0,               0,   1.80374141,
                  "9D",                  0,               0,  2.333056481,
                  "9E",                  0,               0,            0,
                  "9F",                  0,     1.006965294,  2.333056481,
                  "9G",                  0,               0,            0,
                  "9H",                  0,     2.830692732,   6.06602299,
                 "10A",                  0,               0,  0.874433896,
                 "10B",                  0,               0,            0,
                 "10D",                  0,               0,            0,
                 "10E",                  0,     2.830692732,            0,
                 "10F",                  0,               0,            0,
                 "10G",                  0,     1.526777458,            0,
                 "10H",                  0,     2.078731551,            0,
                 "11A",                  0,               0,   1.80374141,
                 "11B",                  0,               0,  1.856218562,
                 "11C",                  0,               0,  2.333056481,
                 "11D",                  0,               0,  2.333056481,
                 "11E",                  0,               0,  2.333056481,
                 "11F",                  0,               0,            0,
                 "11G",                  0,               0,            0,
                 "11H",                  0,               0,            0,
                 "12D",                  0,     2.321050311,  4.034593529,
                 "12F",                  0,               0,            0,
                 "12G",                  0,     2.830692732,  0.238576719,
                 "12H",                  0,     3.439569902,  4.295309968
             )


attach(Familia)
Familia <- Familia[,-1]
rownames(Familia) <- SampleID
#> Warning: Setting row names on a tibble is deprecated.

#remove the rare microbes. It keeps only the microbes that are present in at least 10% of the samples
dim(Familia)
#> [1] 63  3
Familia <- Familia[,colMeans(Familia) >=.1]
dim(Familia)
#> [1] 63  3


Metadata<-tibble::tribble(
            ~SampleID, ~SamplingPoint,         ~Depth,      ~Month,    ~Filter, ~SampleorReplica, ~Dissolved.oxygen,   ~pH,   ~WT, ~Turbidity,   ~ORP, ~Ammonium, ~Nitrates,      ~BGA, ~Chlrophyll,   ~CE,   ~AT, ~Evaporation, ~Precipitation,
                 "1A",         "CEA1",        "80 cm",      "July", "20-25 µm",         "Sample",              4.24,  9.94, 24.48,       87.3,     97,      4.46,       3.6,    279133,        36.6, 1.074, 13.95,         4.34,           2.55,
                 "1C",         "CEA4", "Interstitial",      "July", "20-25 µm",         "Sample",              2.85,  9.98, 24.01,       98.8,  102.9,      4.37,      3.57,    265304,          40, 1.081, 13.95,         4.34,           2.55,
                 "1D",         "CEA1",        "80 cm",    "August", "20-25 µm",         "Sample",              3.81,  9.07, 26.67,       24.9,     94,       5.6,      3.53,     11603,          44, 1.147, 17.11,          5.8,           4.54,
                 "1E",         "CEA3",        "80 cm",    "August", "20-25 µm",         "Sample",              2.64,  8.99, 24.01,       43.1,   63.9,      3.38,      2.55,    218471,          35, 1.156, 17.11,          5.8,           4.54,
                 "1F",         "CEA5",        "80 cm",    "August", "20-25 µm",         "Sample",              4.61,  8.93,  23.5,       49.1,   64.7,      3.21,      2.28,    226658,        32.8, 1.157, 17.11,          5.8,           4.54,
                 "1G",         "CEA2",        "80 cm", "September", "20-25 µm",         "Sample",              5.74,  9.24, 24.46,       68.6,   40.3,      1.93,      0.71,    267389,          44, 1.072,  17.9,         6.86,           6.88,
                 "1H",         "CEA4",        "80 cm", "September", "20-25 µm",         "Sample",              3.69,  9.32, 24.65,       69.8,   48.1,      2.21,       1.2,    267144,        44.8, 1.152,  17.9,         6.86,           6.88,
                 "2A",         "CEA1",        "80 cm",      "July",  "0.45 µm",         "Sample",              4.24,  9.94, 24.48,       87.3,     97,      4.46,       3.6,    279133,        36.6, 1.074, 13.95,         4.34,           2.55,
                 "2B",         "CEA2", "Interstitial",      "July", "20-25 µm",         "Sample",              2.66,    10, 24.92,        113,  111.9,      4.75,      3.21,    270193,        39.8, 1.081, 13.95,         4.34,           2.55,
                 "2C",         "CEA4", "Interstitial",      "July",  "0.45 µm",         "Sample",              2.85,  9.98, 24.01,       98.8,  102.9,      4.37,      3.57,    265304,          40, 1.081, 13.95,         4.34,           2.55,
                 "2D",         "CEA1",        "80 cm",    "August",  "0.45 µm",         "Sample",              3.81,  9.07, 26.67,       24.9,     94,       5.6,      3.53,     11603,          44, 1.147, 17.11,          5.8,           4.54,
                 "2E",         "CEA3",        "80 cm",    "August",  "0.45 µm",         "Sample",              2.64,  8.99, 24.01,       43.1,   63.9,      3.38,      2.55,    218471,          35, 1.156, 17.11,          5.8,           4.54,
                 "2F",         "CEA5",        "80 cm",    "August",  "0.45 µm",         "Sample",              4.61,  8.93,  23.5,       49.1,   64.7,      3.21,      2.28,    226658,        32.8, 1.157, 17.11,          5.8,           4.54,
                 "2H",         "CEA4",        "80 cm", "September",  "0.45 µm",         "Sample",              3.69,  9.32, 24.65,       69.8,   48.1,      2.21,       1.2,    267144,        44.8, 1.152,  17.9,         6.86,           6.88,
                 "3A",         "CEA1", "Interstitial",      "July", "20-25 µm",         "Sample",              2.51, 10.04, 24.35,       87.7,   91.3,       4.5,      3.36,    267716,        39.6, 1.075, 13.95,         4.34,           2.55,
                 "3B",         "CEA2", "Interstitial",      "July",  "0.45 µm",         "Sample",              2.66,    10, 24.92,        113,  111.9,      4.75,      3.21,    270193,        39.8, 1.081, 13.95,         4.34,           2.55,
                 "4A",         "CEA1", "Interstitial",      "July",  "0.45 µm",         "Sample",              2.51, 10.04, 24.35,       87.7,   91.3,       4.5,      3.36,    267716,        39.6, 1.075, 13.95,         4.34,           2.55,
                 "4B",         "CEA3",        "80 cm",      "July", "20-25 µm",         "Sample",              3.04,  9.96, 24.04,       98.5,   98.9,      3.97,      4.35,    279109,          43, 1.083, 13.95,         4.34,           2.55,
                 "4E",         "CEA3", "Interstitial",    "August",  "0.45 µm",         "Sample",              1.83,  8.99, 23.99,         49,   64.1,      3.18,      2.44,    213497,        42.2, 1.155, 17.11,          5.8,           4.54,
                 "4G",         "CEA2", "Interstitial", "September",  "0.45 µm",         "Sample",              3.02,  9.18, 24.14,       66.6,   40.6,      2.19,      0.67,    267007,        43.6, 1.061,  17.9,         6.86,           6.88,
                 "4H",         "CEA4", "Interstitial", "September",  "0.45 µm",         "Sample",               3.3,  9.32, 24.67,       74.1,   49.8,      2.14,      0.87,    261363,        45.1, 1.142,  17.9,         6.86,           6.88,
                 "5E",         "CEA3",        "80 cm",    "August",  "0.45 µm",        "Replica",              2.64,  8.99, 24.01,       43.1,   63.9,      3.38,      2.55,    218471,          35, 1.156, 17.11,          5.8,           4.54,
                 "5F",         "CEA5",        "80 cm",    "August",  "0.45 µm",        "Replica",              4.61,  8.93,  23.5,       49.1,   64.7,      3.21,      2.28,    226658,        32.8, 1.157, 17.11,          5.8,           4.54,
                 "5G",         "CEA2",        "80 cm", "September",  "0.45 µm",        "Replica",              5.74,  9.24, 24.46,       68.6,   40.3,      1.93,      0.71,    267389,          44, 1.072,  17.9,         6.86,           6.88,
                 "6A",         "CEA1",        "80 cm",      "July",  "0.45 µm",        "Replica",              4.24,  9.94, 24.48,       87.3,     97,      4.46,       3.6,    279133,        36.6, 1.074, 13.95,         4.34,           2.55,
                 "6F",         "CEA5", "Interstitial",    "August",  "0.45 µm",        "Replica",              1.82,  8.92, 23.43,       47.6,   60.4,      3.09,      2.06,    242331,        50.2, 1.157, 17.11,          5.8,           4.54,
                 "6H",         "CEA4", "Interstitial", "September",  "0.45 µm",        "Replica",               3.3,  9.32, 24.67,       74.1,   49.8,      2.14,      0.87,    261363,        45.1, 1.142,  17.9,         6.86,           6.88,
                 "7D",         "CEA2",        "80 cm",    "August", "20-25 µm",         "Sample",              8.17,  9.04, 24.88,       46.9,   90.4,      2.81,      2.25,    246979,          34, 1.154, 17.11,          5.8,           4.54,
                 "7F",         "CEA1",        "80 cm", "September", "20-25 µm",         "Sample",              7.69,  9.53, 26.14,       74.2,   67.7,       4.5,       1.3,    272332,        58.5, 1.072,  17.9,         6.86,           6.88,
                 "7G",         "CEA3",        "80 cm", "September", "20-25 µm",         "Sample",              3.07,  9.31, 24.19,       69.9,     42,      1.99,      0.74,    269519,        44.3, 1.152,  17.9,         6.86,           6.88,
                 "8A",         "CEA1", "Interstitial",      "July",  "0.45 µm",        "Replica",              2.51, 10.04, 24.35,       87.7,   91.3,       4.5,      3.36,    267716,        39.6, 1.075, 13.95,         4.34,           2.55,
                 "8B",         "CEA3",        "80 cm",      "July",  "0.45 µm",        "Replica",              3.04,  9.96, 24.04,       98.5,   98.9,      3.97,      4.35,    279109,          43, 1.083, 13.95,         4.34,           2.55,
                 "8C",         "CEA5", "Interstitial",      "July", "20-25 µm",         "Sample",              2.18,  9.97,  24.4,      100.6,  102.7,      5.47,      4.11,    278137,        53.8, 1.078, 13.95,         4.34,           2.55,
                 "8D",         "CEA2",        "80 cm",    "August",  "0.45 µm",         "Sample",              8.17,  9.04, 24.88,       46.9,   90.4,      2.81,      2.25,    246979,          34, 1.154, 17.11,          5.8,           4.54,
                 "8E",         "CEA4",        "80 cm",    "August",  "0.45 µm",         "Sample",              2.63,     9,  24.7,       37.2,   74.9,       4.2,      2.99,    169175,        38.4, 1.179, 17.11,          5.8,           4.54,
                 "8G",         "CEA3",        "80 cm", "September",  "0.45 µm",         "Sample",              3.07,  9.31, 24.19,       69.9,     42,      1.99,      0.74,    269519,        44.3, 1.152,  17.9,         6.86,           6.88,
                 "8H",         "CEA5",        "80 cm", "September",  "0.45 µm",         "Sample",               3.7,  9.14, 22.65,       71.3,   37.1,      2.07,      0.68,    272096,          40, 1.127,  17.9,         6.86,           6.88,
                 "9A",         "CEA2",        "80 cm",      "July", "20-25 µm",         "Sample",              2.58, 10.06, 24.95,       95.2,  108.4,      4.62,      3.98,    279113,        38.9, 1.082, 13.95,         4.34,           2.55,
                 "9B",         "CEA3", "Interstitial",      "July", "20-25 µm",        "Replica",              2.09,  9.95, 24.01,       95.9,   92.8,      4.06,      3.68,    279100,          50, 1.081, 13.95,         4.34,           2.55,
                 "9D",         "CEA2", "Interstitial",    "August", "20-25 µm",         "Sample",              2.16,  8.96,  24.3,         42,     53,      3.19,       2.1,    174271,        50.3, 1.161, 17.11,          5.8,           4.54,
                 "9E",         "CEA4", "Interstitial",    "August", "20-25 µm",         "Sample",               1.7,  9.02, 24.72,       36.1,   63.4,      3.97,      2.55,    159046,        55.9,  1.69, 17.11,          5.8,           4.54,
                 "9F",         "CEA1", "Interstitial", "September", "20-25 µm",         "Sample",               6.8,  9.51, 26.15,       74.4,   73.9,       3.3,      1.11,    271503,        51.3, 1.061,  17.9,         6.86,           6.88,
                 "9G",         "CEA3", "Interstitial", "September", "20-25 µm",         "Sample",              1.95,  9.39,  23.9,       44.4,     42,      3.38,      0.69,    261124,        68.2, 1.147,  17.9,         6.86,           6.88,
                 "9H",         "CEA5", "Interstitial", "September", "20-25 µm",         "Sample",              4.28,  8.85, 20.65,       71.3,   37.5,      1.18,      0.69,    271303,        34.2, 1.102,  17.9,         6.86,           6.88,
                "10A",         "CEA2",        "80 cm",      "July",  "0.45 µm",        "Replica",              2.58, 10.06, 24.95,       95.2,  108.4,      4.62,      3.98,    279113,        38.9, 1.082, 13.95,         4.34,           2.55,
                "10B",         "CEA3", "Interstitial",      "July",  "0.45 µm",        "Replica",              2.09,  9.95, 24.01,       95.9,   92.8,      4.06,      3.68,    279100,          50, 1.081, 13.95,         4.34,           2.55,
                "10D",         "CEA2", "Interstitial",    "August",  "0.45 µm",         "Sample",              2.16,  8.96,  24.3,         42,     53,      3.19,       2.1,    174271,        50.3, 1.161, 17.11,          5.8,           4.54,
                "10E",         "CEA4", "Interstitial",    "August",  "0.45 µm",         "Sample",               1.7,  9.02, 24.72,       36.1,   63.4,      3.97,      2.55,    159046,        55.9,  1.69, 17.11,          5.8,           4.54,
                "10F",         "CEA1", "Interstitial", "September",  "0.45 µm",         "Sample",               6.8,  9.51, 26.15,       74.4,   73.9,       3.3,      1.11,    271503,        51.3, 1.061,  17.9,         6.86,           6.88,
                "10G",         "CEA3", "Interstitial", "September",  "0.45 µm",         "Sample",              1.95,  9.39,  23.9,       44.4,     42,      3.38,      0.69,    261124,        68.2, 1.147,  17.9,         6.86,           6.88,
                "10H",         "CEA5", "Interstitial", "September",  "0.45 µm",         "Sample",              4.28,  8.85, 20.65,       71.3,   37.5,      1.18,      0.69,    271303,        34.2, 1.102,  17.9,         6.86,           6.88,
                "11A",         "CEA2", "Interstitial",      "July", "20-25 µm",        "Replica",              2.66,    10, 24.92,        113,  111.9,      4.75,      3.21,    270193,        39.8, 1.081, 13.95,         4.34,           2.55,
                "11B",         "CEA4",        "80 cm",      "July", "20-25 µm",         "Sample",              3.14,    10,    24,       96.9,    108,      4.48,      3.76,    279119,        38.5,  1.08, 13.95,         4.34,           2.55,
                "11C",         "CEA5", "Interstitial",      "July", "20-25 µm",        "Replica",              2.18,  9.97,  24.4,      100.6,  102.7,      5.47,      4.11,    278137,        53.8, 1.078, 13.95,         4.34,           2.55,
                "11D",         "CEA2",        "80 cm",    "August",  "0.45 µm",        "Replica",              8.17,  9.04, 24.88,       46.9,   90.4,      2.81,      2.25,    246979,          34, 1.154, 17.11,          5.8,           4.54,
                "11E",         "CEA4",        "80 cm",    "August",  "0.45 µm",        "Replica",              2.63,     9,  24.7,       37.2,   74.9,       4.2,      2.99,    169175,        38.4, 1.179, 17.11,          5.8,           4.54,
                "11F",         "CEA1",        "80 cm", "September",  "0.45 µm",        "Replica",              7.69,  9.53, 26.14,       74.2,   67.7,       4.5,       1.3,    272332,        58.5, 1.072,  17.9,         6.86,           6.88,
                "11G",         "CEA3",        "80 cm", "September",  "0.45 µm",        "Replica",              3.07,  9.31, 24.19,       69.9,     42,      1.99,      0.74,    269519,        44.3, 1.152,  17.9,         6.86,           6.88,
                "11H",         "CEA5",        "80 cm", "September",  "0.45 µm",        "Replica",               3.7,  9.14, 22.65,       71.3,   37.1,      2.07,      0.68,    272096,          40, 1.127,  17.9,         6.86,           6.88,
                "12D",         "CEA2", "Interstitial",    "August",  "0.45 µm",        "Replica",              2.16,  8.96,  24.3,         42,     53,      3.19,       2.1,    174271,        50.3, 1.161, 17.11,          5.8,           4.54,
                "12F",         "CEA1", "Interstitial", "September",  "0.45 µm",        "Replica",               6.8,  9.51, 26.15,       74.4,   73.9,       3.3,      1.11,    271503,        51.3, 1.061,  17.9,         6.86,           6.88,
                "12G",         "CEA3", "Interstitial", "September",  "0.45 µm",        "Replica",              1.95,  9.39,  23.9,       44.4,     42,      3.38,      0.69,    261124,        68.2, 1.147,  17.9,         6.86,           6.88,
                "12H",         "CEA5", "Interstitial", "September",  "0.45 µm",        "Replica",              4.28,  8.85, 20.65,       71.3,   37.5,      1.18,      0.69,    271303,        34.2, 1.102,  17.9,         6.86,           6.88
            )
library(vegan)
#> Loading required package: permute
#> Loading required package: lattice
#> This is vegan 2.5-5
# Solo acepta variables numéricas así que debes obviar las variables de texto
rda_object <- vegan::rda(Familia[,-1], Metadata[,7:19], scale=TRUE)
plot(rda_object)

library(BiodiversityR)
#> Loading required package: tcltk
#> Loading required package: vegan3d
#> This version of Shiny is designed to work with 'htmlwidgets' >= 1.5.
#>     Please upgrade via install.packages('htmlwidgets').
#> Loading required package: rgl
#> BiodiversityR 2.11-2: Use command BiodiversityRGUI() to launch the Graphical User Interface; 
#> to see changes use BiodiversityRGUI(changeLog=TRUE, backward.compatibility.messages=TRUE)
PCAsignificance(rda_object, axes=8)
#>                                            1           2
#> eigenvalue                         0.8556295   0.6751456
#> percentage of variance            55.8951791  44.1048209
#> cumulative percentage of variance 55.8951791 100.0000000
#> broken-stick percentage           75.0000000  25.0000000
#> broken-stick cumulative %         75.0000000 100.0000000
#> % > bs%                            0.0000000   1.0000000
#> cum% > bs cum%                     0.0000000   0.0000000

library(devtools)
#> Loading required package: usethis
#> 
#> Attaching package: 'devtools'
#> The following object is masked from 'package:permute':
#> 
#>     check
library(ggord)

summary(rda_object, loadings=TRUE)
#> 
#> Call:
#> rda(X = Familia[, -1], Y = Metadata[, 7:19], scale = TRUE) 
#> 
#> Partitioning of correlations:
#>               Inertia Proportion
#> Total          2.0000     1.0000
#> Constrained    0.4692     0.2346
#> Unconstrained  1.5308     0.7654
#> 
#> Eigenvalues, and their contribution to the correlations 
#> 
#> Importance of components:
#>                         RDA1    RDA2    PC1    PC2
#> Eigenvalue            0.3032 0.16601 0.8556 0.6751
#> Proportion Explained  0.1516 0.08301 0.4278 0.3376
#> Cumulative Proportion 0.1516 0.23461 0.6624 1.0000
#> 
#> Accumulated constrained eigenvalues
#> Importance of components:
#>                         RDA1   RDA2
#> Eigenvalue            0.3032 0.1660
#> Proportion Explained  0.6462 0.3538
#> Cumulative Proportion 0.6462 1.0000
#> 
#> Scaling 2 for species and site scores
#> * Species are scaled proportional to eigenvalues
#> * Sites are unscaled: weighted dispersion equal on all dimensions
#> * General scaling constant of scores:  3.336994 
#> 
#> 
#> Species scores
#> 
#>                  RDA1    RDA2    PC1     PC2
#> Microcystaceae 1.2858  0.1385 0.8039  1.8025
#> Nostocaceae    0.1871 -0.9514 2.0292 -0.7141
#> 
#> 
#> Site scores (weighted sums of species scores)
#> 
#>          RDA1     RDA2      PC1       PC2
#> sit1  -0.5182  0.60559 -0.31478  0.193657
#> sit2  -0.5182  0.60559 -0.41778 -0.030060
#> sit3  -0.3782 -0.69443  0.13128 -0.040889
#> sit4  -0.4024 -0.46983  0.17089 -0.314519
#> sit5  -0.5182  0.60559 -0.35537 -0.332953
#> sit6  -0.5182  0.60559 -0.44806 -0.355111
#> sit7   2.9945  0.66419  0.62699  1.693459
#> sit8  -0.3702 -0.76901  0.25406 -0.060046
#> sit9  -0.5182  0.60559 -0.60514  0.291356
#> sit10  0.5502  0.81572 -0.18104  0.642632
#> sit11 -0.5182  0.60559 -0.40670  0.199049
#> sit12 -0.3372 -1.07592  0.42171 -0.426383
#> sit13  1.6625  1.03449  0.12781  1.040036
#> sit14 -0.3372 -1.07592  0.30306 -0.672284
#> sit15 -0.2877 -1.53539  0.68669 -0.402184
#> sit16 -0.1618 -2.70462  0.76471 -0.319594
#> sit17 -0.5182  0.60559 -0.19930 -0.007034
#> sit18 -0.5182  0.60559 -0.25059 -0.077542
#> sit19 -0.5182  0.60559 -0.35412 -0.089192
#> sit20 -0.5182  0.60559 -0.65337  0.017435
#> sit21  0.5005 -1.65181  0.65096 -0.275531
#> sit22 -0.5182  0.60559 -0.27414 -0.116034
#> sit23  0.9765  0.89957 -0.02418  0.608158
#> sit24  0.5715  0.81990 -0.20661  0.330954
#> sit25 -0.3372 -1.07592  0.38107 -0.116692
#> sit26 -0.5182  0.60559 -0.44488  0.035648
#> sit27  1.2487  0.95311 -0.12183  0.802933
#> sit28 -0.5182  0.60559 -0.36202 -0.168003
#> sit29  0.6555  0.83643  0.24832  0.303220
#> sit30 -0.5182  0.60559 -0.44411 -0.441234
#> sit31 -0.5182  0.60559 -0.19930 -0.007034
#> sit32 -0.5182  0.60559 -0.25059 -0.077542
#> sit33 -0.5182  0.60559 -0.29397  0.240786
#> sit34  0.9765  0.89957 -0.03083  0.773108
#> sit35 -0.5182  0.60559 -0.32221  0.045388
#> sit36  1.2468 -0.63404  0.55293  0.277916
#> sit37  1.3953  0.98194 -0.19689  0.592240
#> sit38 -0.3782 -0.69443  0.26465 -0.031609
#> sit39 -0.3782 -0.69443  0.19911 -0.143644
#> sit40 -0.3372 -1.07592  0.35466 -0.385298
#> sit41 -0.5182  0.60559 -0.23155 -0.555497
#> sit42  0.1946 -0.97134  0.55074 -0.235192
#> sit43 -0.5182  0.60559 -0.21058 -0.329458
#> sit44  1.4473 -3.47240  1.04843 -0.484502
#> sit45 -0.4504 -0.02464 -0.01252  0.092010
#> sit46 -0.5182  0.60559 -0.33887  0.096294
#> sit47 -0.5182  0.60559 -0.34119 -0.074949
#> sit48  0.9765  0.89957  0.09965  0.385613
#> sit49 -0.5182  0.60559 -0.26293 -0.259626
#> sit50  0.2880  0.76415 -0.03194  0.178144
#> sit51  0.5795  0.82148 -0.84878  0.072412
#> sit52 -0.3782 -0.69443 -0.06716  0.051418
#> sit53 -0.3742 -0.73225  0.17886 -0.265612
#> sit54 -0.3372 -1.07592  0.40188 -0.069562
#> sit55 -0.3372 -1.07592  0.33383 -0.478351
#> sit56 -0.3372 -1.07592  0.37364 -0.264961
#> sit57 -0.5182  0.60559 -0.01175 -0.435767
#> sit58 -0.5182  0.60559 -0.44411 -0.441234
#> sit59 -0.5182  0.60559 -0.62088 -0.612537
#> sit60  1.0205 -2.06121  1.13372  0.160031
#> sit61 -0.5182  0.60559 -0.26293 -0.259626
#> sit62  0.9951  0.72762  0.19178  0.579916
#> sit63  1.6314 -2.13295  0.59154 -0.046527
#> 
#> 
#> Site constraints (linear combinations of constraining variables)
#> 
#>            RDA1       RDA2      PC1       PC2
#> con1  -0.505223 -0.2085999 -0.31478  0.193657
#> con2  -0.129575 -0.1864869 -0.41778 -0.030060
#> con3  -0.435242 -0.3949468  0.13128 -0.040889
#> con4  -0.138605  0.1826363  0.17089 -0.314519
#> con5   0.210023  0.2407644 -0.35537 -0.332953
#> con6   0.316282  0.0806129 -0.44806 -0.355111
#> con7   0.278841  0.1962513  0.62699  1.693459
#> con8  -0.505223 -0.2085999  0.25406 -0.060046
#> con9  -0.388529 -0.8782862 -0.60514  0.291356
#> con10 -0.129575 -0.1864869 -0.18104  0.642632
#> con11 -0.435242 -0.3949468 -0.40670  0.199049
#> con12 -0.138605  0.1826363  0.42171 -0.426383
#> con13  0.210023  0.2407644  0.12781  1.040036
#> con14  0.278841  0.1962513  0.30306 -0.672284
#> con15 -0.342271  0.2203889  0.68669 -0.402184
#> con16 -0.388529 -0.8782862  0.76471 -0.319594
#> con17 -0.342271  0.2203889 -0.19930 -0.007034
#> con18 -0.208119  0.1903086 -0.25059 -0.077542
#> con19 -0.106376 -0.0017517 -0.35412 -0.089192
#> con20  0.006212 -0.6979111 -0.65337  0.017435
#> con21  0.312003 -0.0936548  0.65096 -0.275531
#> con22 -0.138605  0.1826363 -0.27414 -0.116034
#> con23  0.210023  0.2407644 -0.02418  0.608158
#> con24  0.316282  0.0806129 -0.20661  0.330954
#> con25 -0.505223 -0.2085999  0.38107 -0.116692
#> con26 -0.191887 -0.3058754 -0.44488  0.035648
#> con27  0.312003 -0.0936548 -0.12183  0.802933
#> con28  0.002199  0.0618938 -0.36202 -0.168003
#> con29  0.055352  1.0204349  0.24832  0.303220
#> con30  0.424393  0.1749367 -0.44411 -0.441234
#> con31 -0.342271  0.2203889 -0.19930 -0.007034
#> con32 -0.208119  0.1903086 -0.25059 -0.077542
#> con33 -0.583613 -0.2150132 -0.29397  0.240786
#> con34  0.002199  0.0618938 -0.03083  0.773108
#> con35 -0.307188 -0.0742157 -0.32221  0.045388
#> con36  0.424393  0.1749367  0.55293  0.277916
#> con37  0.793989 -0.0008145 -0.19689  0.592240
#> con38 -0.558905 -0.1417627  0.26465 -0.031609
#> con39 -0.359096 -0.1581716  0.19911 -0.143644
#> con40 -0.135623  0.0093748  0.35466 -0.385298
#> con41  0.394260  0.7081451 -0.23155 -0.555497
#> con42  0.037767  0.3490231  0.55074 -0.235192
#> con43  0.084282  0.5222431 -0.21058 -0.329458
#> con44  1.196374 -0.9218995  1.04843 -0.484502
#> con45 -0.558905 -0.1417627 -0.01252  0.092010
#> con46 -0.359096 -0.1581716 -0.33887  0.096294
#> con47 -0.135623  0.0093748 -0.34119 -0.074949
#> con48  0.394260  0.7081451  0.09965  0.385613
#> con49  0.037767  0.3490231 -0.26293 -0.259626
#> con50  0.084282  0.5222431 -0.03194  0.178144
#> con51  1.196374 -0.9218995 -0.84878  0.072412
#> con52 -0.388529 -0.8782862 -0.06716  0.051418
#> con53 -0.180285 -0.1132616  0.17886 -0.265612
#> con54 -0.583613 -0.2150132  0.40188 -0.069562
#> con55  0.002199  0.0618938  0.33383 -0.478351
#> con56 -0.307188 -0.0742157  0.37364 -0.264961
#> con57  0.055352  1.0204349 -0.01175 -0.435767
#> con58  0.424393  0.1749367 -0.44411 -0.441234
#> con59  0.793989 -0.0008145 -0.62088 -0.612537
#> con60 -0.135623  0.0093748  1.13372  0.160031
#> con61  0.037767  0.3490231 -0.26293 -0.259626
#> con62  0.084282  0.5222431  0.19178  0.579916
#> con63  1.196374 -0.9218995  0.59154 -0.046527
#> 
#> 
#> Biplot scores for constraining variables
#> 
#>                      RDA1     RDA2 PC1 PC2
#> Dissolved.oxygen  0.22068  0.20399   0   0
#> pH               -0.59164 -0.08247   0   0
#> WT               -0.61565  0.39028   0   0
#> Turbidity        -0.24107 -0.33520   0   0
#> ORP              -0.78535 -0.21349   0   0
#> Ammonium         -0.84956  0.04916   0   0
#> Nitrates         -0.78493 -0.18740   0   0
#> BGA               0.13815 -0.01239   0   0
#> Chlrophyll       -0.05463  0.49500   0   0
#> CE                0.23360  0.33560   0   0
#> AT                0.68488  0.29878   0   0
#> Evaporation       0.73787  0.27810   0   0

levels(Metadata$Month) <- c("Jul","Aug","Sep")
Familia <- Metadata$Month
bg <- c("#ff7f00","#1f78b4","#ffff33","#a6cee3","#33a02c","#e31a1c") # 6 nice colors for our ecotypes
levels(Metadata$Month) <- c("Jul","Aug","Sep")
Familia <- Metadata$Month
bg <- c("#ff7f00","#1f78b4","#ffff33","#a6cee3","#33a02c","#e31a1c") # 6 nice colors for our ecotypes

# axes 1 & 2
plot(rda_object, type = "n", scaling=3, display = "sites", xlab = "RDA1 (17.68%)", ylab = "RDA2 (13.72%)")
points(rda_object, display="sites", pch=20, cex=0.7, col="gray32", scaling=3)           
points(rda_object, display="sites", pch=21, cex=1.3, col="gray32", scaling=3, bg=bg[Familia])
text(rda_object, scaling=3, display="bp", col="#0868ac", cex=1, face ="bold")
#> Warning in arrows(0, 0, pts[, 1], pts[, 2], length = head.arrow, ...):
#> "face" is not a graphical parameter
#> Warning in strwidth(labels, ...): "face" is not a graphical parameter
#> Warning in strheight(labels, ...): "face" is not a graphical parameter
#> Warning in text.default(pts, labels = rownames(pts), ...): "face" is not a
#> graphical parameter
legend("bottomright", legend=levels(Familia), bty="n",xpd= FALSE, col="gray32", pch=21, cex=1, pt.bg=bg)

Created on 2020-02-07 by the reprex package (v0.3.0)

Previously I had already done this analysis and the differences I found regarding this one that a variable is not contemplating is the following:
The correct analysis: Alias, Type: NULL, Value: Pairlist of leght 0
Analysis that does not include the variable Precipitation: Alias, Character [1], Value: Precipitation

Anyone know what that difference means?

Thank you in advance