diff --git a/backend/geonature/core/gn_monitoring/models.py b/backend/geonature/core/gn_monitoring/models.py
index b764fa6a00..6ba3a45ca7 100644
--- a/backend/geonature/core/gn_monitoring/models.py
+++ b/backend/geonature/core/gn_monitoring/models.py
@@ -7,7 +7,7 @@
 from geoalchemy2 import Geometry
 from sqlalchemy import ForeignKey
 from sqlalchemy.orm import relationship
-from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.dialects.postgresql import UUID, JSONB
 from sqlalchemy.sql import select, func
 
 
@@ -16,12 +16,13 @@
 from utils_flask_sqla.serializers import serializable
 from utils_flask_sqla_geo.serializers import geoserializable
 
+from pypnnomenclature.models import TNomenclatures
 from geonature.core.gn_commons.models import TModules
 from geonature.core.gn_meta.models import TDatasets
 from geonature.utils.env import DB
 
 
-corVisitObserver = DB.Table(
+cor_visit_observer = DB.Table(
     "cor_visit_observer",
     DB.Column(
         "id_base_visit",
@@ -39,7 +40,7 @@
 )
 
 
-corSiteModule = DB.Table(
+cor_site_module = DB.Table(
     "cor_site_module",
     DB.Column(
         "id_base_site",
@@ -56,7 +57,7 @@
     schema="gn_monitoring",
 )
 
-corSiteArea = DB.Table(
+cor_site_area = DB.Table(
     "cor_site_area",
     DB.Column(
         "id_base_site",
@@ -68,6 +69,58 @@
     schema="gn_monitoring",
 )
 
+cor_module_type = DB.Table(
+    "cor_module_type",
+    DB.Column(
+        "id_module",
+        DB.Integer,
+        DB.ForeignKey("gn_commons.t_modules.id_module"),
+        primary_key=True,
+    ),
+    DB.Column(
+        "id_type_site",
+        DB.Integer,
+        DB.ForeignKey("gn_monitoring.bib_type_site.id_nomenclature_type_site"),
+        primary_key=True,
+    ),
+    schema="gn_monitoring",
+)
+
+cor_site_type = DB.Table(
+    "cor_site_type",
+    DB.Column(
+        "id_base_site",
+        DB.Integer,
+        DB.ForeignKey("gn_monitoring.t_base_sites.id_base_site"),
+        primary_key=True,
+    ),
+    DB.Column(
+        "id_type_site",
+        DB.Integer,
+        DB.ForeignKey("gn_monitoring.bib_type_site.id_nomenclature_type_site"),
+        primary_key=True,
+    ),
+    schema="gn_monitoring",
+)
+
+
+@serializable
+class BibTypeSite(DB.Model):
+    __tablename__ = "bib_type_site"
+    __table_args__ = {"schema": "gn_monitoring"}
+
+    id_nomenclature_type_site = DB.Column(
+        DB.ForeignKey("ref_nomenclatures.t_nomenclatures.id_nomenclature"),
+        nullable=False,
+        primary_key=True,
+    )
+    config = DB.Column(JSONB)
+    nomenclature = DB.relationship(
+        TNomenclatures, uselist=False, backref=DB.backref("bib_type_site", uselist=False)
+    )
+
+    sites = DB.relationship("TBaseSites", secondary=cor_site_type, lazy="noload")
+
 
 @serializable
 class TBaseVisits(DB.Model):
@@ -84,7 +137,7 @@ class TBaseVisits(DB.Model):
     # Pour le moment non défini comme une clé étrangère
     #   pour les questions de perfs
     #   a voir en fonction des usage
-    id_module = DB.Column(DB.Integer)
+    id_module = DB.Column(DB.Integer, ForeignKey("gn_commons.t_modules.id_module"))
 
     visit_date_min = DB.Column(DB.DateTime)
     visit_date_max = DB.Column(DB.DateTime)
@@ -102,15 +155,16 @@ class TBaseVisits(DB.Model):
 
     observers = DB.relationship(
         User,
-        secondary=corVisitObserver,
-        primaryjoin=(corVisitObserver.c.id_base_visit == id_base_visit),
-        secondaryjoin=(corVisitObserver.c.id_role == User.id_role),
-        foreign_keys=[corVisitObserver.c.id_base_visit, corVisitObserver.c.id_role],
+        secondary=cor_visit_observer,
+        primaryjoin=(cor_visit_observer.c.id_base_visit == id_base_visit),
+        secondaryjoin=(cor_visit_observer.c.id_role == User.id_role),
+        foreign_keys=[cor_visit_observer.c.id_base_visit, cor_visit_observer.c.id_role],
     )
 
+    observers_txt = DB.Column(DB.Unicode)
+
     dataset = relationship(
         TDatasets,
-        lazy="joined",
         primaryjoin=(TDatasets.id_dataset == id_dataset),
         foreign_keys=[id_dataset],
     )
@@ -128,7 +182,6 @@ class TBaseSites(DB.Model):
     id_base_site = DB.Column(DB.Integer, primary_key=True)
     id_inventor = DB.Column(DB.Integer, ForeignKey("utilisateurs.t_roles.id_role"))
     id_digitiser = DB.Column(DB.Integer, ForeignKey("utilisateurs.t_roles.id_role"))
-    id_nomenclature_type_site = DB.Column(DB.Integer)
     base_site_name = DB.Column(DB.Unicode)
     base_site_description = DB.Column(DB.Unicode)
     base_site_code = DB.Column(DB.Unicode)
@@ -153,8 +206,23 @@ class TBaseSites(DB.Model):
         "TModules",
         lazy="select",
         enable_typechecks=False,
-        secondary=corSiteModule,
-        primaryjoin=(corSiteModule.c.id_base_site == id_base_site),
-        secondaryjoin=(corSiteModule.c.id_module == TModules.id_module),
-        foreign_keys=[corSiteModule.c.id_base_site, corSiteModule.c.id_module],
+        secondary=cor_site_module,
+        primaryjoin=(cor_site_module.c.id_base_site == id_base_site),
+        secondaryjoin=(cor_site_module.c.id_module == TModules.id_module),
+        foreign_keys=[cor_site_module.c.id_base_site, cor_site_module.c.id_module],
+    )
+
+
+@serializable
+class TObservations(DB.Model):
+    __tablename__ = "t_observations"
+    __table_args__ = {"schema": "gn_monitoring"}
+    id_observation = DB.Column(DB.Integer, primary_key=True, nullable=False, unique=True)
+    id_base_visit = DB.Column(DB.ForeignKey("gn_monitoring.t_base_visits.id_base_visit"))
+    id_digitiser = DB.Column(DB.Integer, DB.ForeignKey("utilisateurs.t_roles.id_role"))
+    digitiser = DB.relationship(
+        User, primaryjoin=(User.id_role == id_digitiser), foreign_keys=[id_digitiser]
     )
+    cd_nom = DB.Column(DB.Integer)
+    comments = DB.Column(DB.String)
+    uuid_observation = DB.Column(UUID(as_uuid=True), default=select(func.uuid_generate_v4()))
diff --git a/backend/geonature/core/gn_monitoring/routes.py b/backend/geonature/core/gn_monitoring/routes.py
index 0ad5889009..245ed06047 100644
--- a/backend/geonature/core/gn_monitoring/routes.py
+++ b/backend/geonature/core/gn_monitoring/routes.py
@@ -1,6 +1,6 @@
 from flask import Blueprint, request
 from geojson import FeatureCollection
-from geonature.core.gn_monitoring.models import TBaseSites, corSiteArea, corSiteModule
+from geonature.core.gn_monitoring.models import TBaseSites, cor_site_area, cor_site_module
 from geonature.utils.env import DB
 from ref_geo.models import LAreas
 from sqlalchemy import select
@@ -79,17 +79,16 @@ def get_site_areas(id_site):
     params = request.args
 
     query = (
-        # TODO@LAreas.geom_4326
-        select(corSiteArea, func.ST_Transform(LAreas.geom, 4326))
-        .join(LAreas, LAreas.id_area == corSiteArea.c.id_area)
-        .where(corSiteArea.c.id_base_site == id_site)
+        select(cor_site_area, func.ST_Transform(LAreas.geom, 4326))
+        .join(LAreas, LAreas.id_area == cor_site_area.c.id_area)
+        .where(cor_site_area.c.id_base_site == id_site)
     )
 
     if "id_area_type" in params:
         query = query.where(LAreas.id_type == params["id_area_type"])
     if "id_module" in params:
-        query = query.join(corSiteModule, corSiteModule.c.id_base_site == id_site).where(
-            corSiteModule.c.id_module == params["id_module"]
+        query = query.join(cor_site_module, cor_site_module.c.id_base_site == id_site).where(
+            cor_site_module.c.id_module == params["id_module"]
         )
 
     data = DB.session.scalars(query).all()
diff --git a/backend/geonature/migrations/versions/6734d8f7eb2a_monitoring_add_id_digitizer_to_t_observations.py b/backend/geonature/migrations/versions/6734d8f7eb2a_monitoring_add_id_digitizer_to_t_observations.py
new file mode 100644
index 0000000000..f17add3506
--- /dev/null
+++ b/backend/geonature/migrations/versions/6734d8f7eb2a_monitoring_add_id_digitizer_to_t_observations.py
@@ -0,0 +1,67 @@
+"""[monitoring] add id_digitizer to t_observations
+
+Revision ID: 6734d8f7eb2a
+Revises: 9b88459c1298
+Create Date: 2024-01-16 15:50:30.308266
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "6734d8f7eb2a"
+down_revision = "9b88459c1298"
+branch_labels = None
+depends_on = None
+
+
+monitorings_schema = "gn_monitoring"
+table = "t_observations"
+column = "id_digitiser"
+
+foreign_schema = "utilisateurs"
+table_foreign = "t_roles"
+foreign_key = "id_role"
+
+
+def upgrade():
+    op.add_column(
+        table,
+        sa.Column(
+            column,
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{foreign_schema}.{table_foreign}.{foreign_key}",
+                name=f"fk_{table}_{column}",
+                onupdate="CASCADE",
+            ),
+        ),
+        schema=monitorings_schema,
+    )
+    op.execute(
+        """
+        UPDATE gn_monitoring.t_observations o SET id_digitiser = tbv.id_digitiser
+        FROM gn_monitoring.t_base_visits AS tbv
+        WHERE tbv.id_base_visit = o.id_base_visit;
+        """
+    )
+    # Set not null constraint
+    op.alter_column(
+        table_name=table,
+        column_name=column,
+        existing_type=sa.Integer(),
+        nullable=False,
+        schema=monitorings_schema,
+    )
+
+
+def downgrade():
+    statement = sa.text(
+        f"""
+        ALTER TABLE {monitorings_schema}.{table} DROP CONSTRAINT fk_{table}_{column};
+        """
+    )
+    op.execute(statement)
+    op.drop_column(table, column, schema=monitorings_schema)
diff --git a/backend/geonature/migrations/versions/8309591841f3_monitoring_add_observers_txt_column_t_base_visit.py b/backend/geonature/migrations/versions/8309591841f3_monitoring_add_observers_txt_column_t_base_visit.py
new file mode 100644
index 0000000000..9ffe7de1de
--- /dev/null
+++ b/backend/geonature/migrations/versions/8309591841f3_monitoring_add_observers_txt_column_t_base_visit.py
@@ -0,0 +1,38 @@
+"""[monitoring] add_observers_txt_column_t_base_visit
+
+Revision ID: 8309591841f3
+Revises: 7b6a578eccd7
+Create Date: 2023-10-06 11:07:43.532623
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "8309591841f3"
+down_revision = "7b6a578eccd7"
+branch_labels = None
+depends_on = None
+
+
+monitorings_schema = "gn_monitoring"
+table = "t_base_visits"
+column = "observers_txt"
+
+
+def upgrade():
+    op.add_column(
+        table,
+        sa.Column(
+            column,
+            sa.Text(),
+            nullable=True,
+        ),
+        schema=monitorings_schema,
+    )
+
+
+def downgrade():
+    op.drop_column(table, column, schema=monitorings_schema)
diff --git a/backend/geonature/migrations/versions/9b88459c1298_monitoring_create_t_observations.py b/backend/geonature/migrations/versions/9b88459c1298_monitoring_create_t_observations.py
new file mode 100644
index 0000000000..7e5b55d11b
--- /dev/null
+++ b/backend/geonature/migrations/versions/9b88459c1298_monitoring_create_t_observations.py
@@ -0,0 +1,55 @@
+"""[monitoring] create t_observations
+
+Revision ID: 9b88459c1298
+Revises: a54bafb13ce8
+Create Date: 2024-01-16 15:41:13.331912
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "9b88459c1298"
+down_revision = "a54bafb13ce8"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.execute(
+        """
+        CREATE TABLE IF NOT EXISTS gn_monitoring.t_observations (
+                id_observation SERIAL NOT NULL,
+                id_base_visit INTEGER NOT NULL,
+                cd_nom INTEGER NOT NULL,
+                comments TEXT,
+                uuid_observation UUID DEFAULT uuid_generate_v4() NOT NULL,
+
+
+                CONSTRAINT pk_t_observations PRIMARY KEY (id_observation),
+                CONSTRAINT fk_t_observations_id_base_visit FOREIGN KEY (id_base_visit)
+                    REFERENCES gn_monitoring.t_base_visits (id_base_visit) MATCH SIMPLE
+                    ON UPDATE CASCADE ON DELETE CASCADE
+            );
+    """
+    )
+    op.execute(
+        """
+        INSERT INTO gn_commons.bib_tables_location(table_desc, schema_name, table_name, pk_field, uuid_field_name)
+        VALUES
+        ('Table centralisant les observations réalisées lors d''une visite sur un site', 'gn_monitoring', 't_observations', 'id_observation', 'uuid_observation')
+        ON CONFLICT(schema_name, table_name) DO NOTHING;
+        """
+    )
+
+
+def downgrade():
+    op.execute(
+        """
+        DELETE FROM gn_commons.bib_tables_location
+        WHERE schema_name = 'gn_monitoring' AND table_name = 't_observations';
+        """
+    )
+    op.drop_table("t_observations", schema="gn_monitoring")
diff --git a/backend/geonature/migrations/versions/a54bafb13ce8_monitoring_create_cor_module_type.py b/backend/geonature/migrations/versions/a54bafb13ce8_monitoring_create_cor_module_type.py
new file mode 100644
index 0000000000..3c867d9526
--- /dev/null
+++ b/backend/geonature/migrations/versions/a54bafb13ce8_monitoring_create_cor_module_type.py
@@ -0,0 +1,64 @@
+""" [monitoring] create_cor_module_type
+
+Revision ID: a54bafb13ce8
+Revises: ce54ba49ce5c
+Create Date: 2022-12-06 16:18:24.512562
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "a54bafb13ce8"
+down_revision = "ce54ba49ce5c"
+branch_labels = None
+depends_on = None
+
+monitorings_schema = "gn_monitoring"
+referent_schema = "gn_commons"
+
+
+def upgrade():
+    op.create_table(
+        "cor_module_type",
+        sa.Column(
+            "id_type_site",
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{monitorings_schema}.bib_type_site.id_nomenclature_type_site",
+                name="fk_cor_module_type_id_nomenclature",
+                ondelete="CASCADE",
+                onupdate="CASCADE",
+            ),
+            nullable=False,
+        ),
+        sa.Column(
+            "id_module",
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{referent_schema}.t_modules.id_module",
+                name="fk_cor_module_type_id_module",
+                ondelete="CASCADE",
+                onupdate="CASCADE",
+            ),
+            nullable=False,
+        ),
+        sa.PrimaryKeyConstraint("id_type_site", "id_module", name="pk_cor_module_type"),
+        schema=monitorings_schema,
+    )
+
+    # Insertion des données a partir de cor_site_module
+    op.execute(
+        """
+        INSERT INTO gn_monitoring.cor_module_type (id_module, id_type_site )
+        SELECT DISTINCT csm.id_module, cts.id_type_site
+        FROM gn_monitoring.cor_site_module AS csm
+        JOIN gn_monitoring.cor_site_type AS cts
+        ON Cts.id_base_site = csm.id_base_site ;
+    """
+    )
+
+
+def downgrade():
+    op.drop_table("cor_module_type", schema=monitorings_schema)
diff --git a/backend/geonature/migrations/versions/b53bafb13ce8_monitoring_create_bib_type_site.py b/backend/geonature/migrations/versions/b53bafb13ce8_monitoring_create_bib_type_site.py
new file mode 100644
index 0000000000..0c66d8ece2
--- /dev/null
+++ b/backend/geonature/migrations/versions/b53bafb13ce8_monitoring_create_bib_type_site.py
@@ -0,0 +1,77 @@
+"""[monitoring] create_bib_type_site
+
+Revision ID: b53bafb13ce8
+Revises: 8309591841f3
+Create Date: 2022-12-06 16:18:24.512562
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "b53bafb13ce8"
+down_revision = "8309591841f3"
+branch_labels = None
+depends_on = None
+
+monitorings_schema = "gn_monitoring"
+nomenclature_schema = "ref_nomenclatures"
+
+
+def upgrade():
+    op.create_table(
+        "bib_type_site",
+        sa.Column(
+            "id_nomenclature_type_site",
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{nomenclature_schema}.t_nomenclatures.id_nomenclature",
+                name="fk_t_nomenclatures_id_nomenclature_type_site",
+            ),
+            nullable=False,
+            unique=True,
+        ),
+        sa.PrimaryKeyConstraint("id_nomenclature_type_site"),
+        sa.Column("config", sa.JSON(), nullable=True),
+        schema=monitorings_schema,
+    )
+
+    # FIXME: if sqlalchemy >= 1.4.32, it should work with postgresql_not_valid=True: cleaner
+    # op.create_check_constraint(
+    #     "ck_bib_type_site_id_nomenclature_type_site",
+    #     "bib_type_site",
+    #     f"{nomenclature_schema}.check_nomenclature_type_by_mnemonique(id_nomenclature_type_site,'TYPE_SITE')",
+    #     schema=monitorings_schema,
+    #     postgresql_not_valid=True
+    # )
+    statement = sa.text(
+        f"""
+        ALTER TABLE {monitorings_schema}.bib_type_site
+        ADD
+          CONSTRAINT ck_bib_type_site_id_nomenclature_type_site CHECK (
+            {nomenclature_schema}.check_nomenclature_type_by_mnemonique(
+              id_nomenclature_type_site, 'TYPE_SITE' :: character varying
+            )
+          ) NOT VALID
+        """
+    )
+    op.execute(statement)
+    op.create_table_comment(
+        "bib_type_site",
+        "Table de définition des champs associés aux types de sites",
+        schema=monitorings_schema,
+    )
+
+    # Récupération de la liste des types de site avec ceux déja présents dans la table t_base_site
+    op.execute(
+        """
+        INSERT INTO gn_monitoring.bib_type_site AS bts  (id_nomenclature_type_site)
+        SELECT DISTINCT id_nomenclature_type_site
+        FROM gn_monitoring.t_base_sites AS tbs ;
+    """
+    )
+
+
+def downgrade():
+    op.drop_table("bib_type_site", schema=monitorings_schema)
diff --git a/backend/geonature/migrations/versions/ce54ba49ce5c_monitoring_create_cor_site_type.py b/backend/geonature/migrations/versions/ce54ba49ce5c_monitoring_create_cor_site_type.py
new file mode 100644
index 0000000000..d1a4296713
--- /dev/null
+++ b/backend/geonature/migrations/versions/ce54ba49ce5c_monitoring_create_cor_site_type.py
@@ -0,0 +1,130 @@
+"""[monitoring] create_cor_site_type
+
+Revision ID: ce54ba49ce5c
+Revises: b53bafb13ce8
+Create Date: 2022-12-06 16:18:24.512562
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "ce54ba49ce5c"
+down_revision = "b53bafb13ce8"
+branch_labels = None
+depends_on = None
+
+monitorings_schema = "gn_monitoring"
+
+
+def upgrade():
+    op.create_table(
+        "cor_site_type",
+        sa.Column(
+            "id_type_site",
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{monitorings_schema}.bib_type_site.id_nomenclature_type_site",
+                name="fk_cor_site_type_id_nomenclature_type_site",
+                ondelete="CASCADE",
+                onupdate="CASCADE",
+            ),
+            nullable=False,
+        ),
+        sa.Column(
+            "id_base_site",
+            sa.Integer(),
+            sa.ForeignKey(
+                f"{monitorings_schema}.t_base_sites.id_base_site",
+                name="fk_cor_site_type_id_base_site",
+                ondelete="CASCADE",
+                onupdate="CASCADE",
+            ),
+            nullable=False,
+        ),
+        sa.PrimaryKeyConstraint("id_type_site", "id_base_site", name="pk_cor_site_type"),
+        schema=monitorings_schema,
+    )
+    op.create_table_comment(
+        "cor_site_type",
+        "Table d'association entre les sites et les types de sites",
+        schema=monitorings_schema,
+    )
+
+    op.execute(
+        """
+        INSERT INTO  gn_monitoring.cor_site_type
+        SELECT id_nomenclature_type_site , id_base_site d
+        FROM gn_monitoring.t_base_sites ;
+    """
+    )
+
+    op.execute(
+        """
+        ALTER TABLE gn_monitoring.t_base_sites
+        DROP CONSTRAINT check_t_base_sites_type_site;
+    """
+    )
+    op.execute(
+        """
+        DROP INDEX gn_monitoring.idx_t_base_sites_type_site;
+    """
+    )
+    op.drop_column(
+        table_name="t_base_sites",
+        column_name="id_nomenclature_type_site",
+        schema=monitorings_schema,
+    )
+
+
+def downgrade():
+    op.add_column(
+        table_name="t_base_sites",
+        column=sa.Column(
+            "id_nomenclature_type_site",
+            sa.Integer(),
+            sa.ForeignKey(
+                "ref_nomenclatures.t_nomenclatures.id_nomenclature",
+                name="fk_t_base_sites_type_site",
+                onupdate="CASCADE",
+            ),
+        ),
+        schema=monitorings_schema,
+    )
+
+    op.execute(
+        """
+        WITH ts AS (
+            SELECT DISTINCT ON (id_base_site) id_base_site, id_type_site
+            FROM gn_monitoring.cor_site_type AS cts
+            ORDER BY id_base_site, id_type_site
+        )
+        UPDATE gn_monitoring.t_base_sites tbs
+            SET id_nomenclature_type_site = id_type_site
+        FROM ts
+        WHERE ts.id_base_site = tbs.id_base_site;
+    """
+    )
+
+    op.execute(
+        """
+        ALTER TABLE gn_monitoring.t_base_sites
+        ADD CONSTRAINT check_t_base_sites_type_site
+        CHECK (ref_nomenclatures.check_nomenclature_type_by_mnemonique(id_nomenclature_type_site,'TYPE_SITE'))
+        NOT VALID;
+    """
+    )
+
+    op.execute(
+        """
+        CREATE INDEX idx_t_base_sites_type_site ON gn_monitoring.t_base_sites USING btree (id_nomenclature_type_site);
+    """
+    )
+    op.execute(
+        """
+        ALTER TABLE gn_monitoring.t_base_sites ALTER COLUMN id_nomenclature_type_site SET NOT NULL;
+    """
+    )
+
+    op.drop_table("cor_site_type", schema=monitorings_schema)
diff --git a/frontend/src/app/GN2CommonModule/form/datalist/datalist.component.ts b/frontend/src/app/GN2CommonModule/form/datalist/datalist.component.ts
index 317a8e2cb3..0a2c830a29 100644
--- a/frontend/src/app/GN2CommonModule/form/datalist/datalist.component.ts
+++ b/frontend/src/app/GN2CommonModule/form/datalist/datalist.component.ts
@@ -1,13 +1,4 @@
-import { filter } from 'rxjs/operators';
-import {
-  Component,
-  OnInit,
-  Input,
-  OnChanges,
-  DoCheck,
-  IterableDiffers,
-  IterableDiffer,
-} from '@angular/core';
+import { Component, OnInit, Input } from '@angular/core';
 import { DataFormService } from '../data-form.service';
 import { GenericFormComponent } from '@geonature_common/form/genericForm.component';
 import { CommonService } from '../../service/common.service';
@@ -37,6 +28,7 @@ export class DatalistComponent extends GenericFormComponent implements OnInit {
   @Input() filters = {}; // help
 
   @Input() default;
+  @Input() nullDefault;
 
   @Input() dataPath: string; // pour atteindre la liste si elle n'est pas à la racine de la réponse de l'api.
   // si on a 'data/liste' on mettra dataPath='data'
@@ -70,7 +62,15 @@ export class DatalistComponent extends GenericFormComponent implements OnInit {
 
   getFilteredValues() {
     let values = this.values || [];
-
+    // if(this.nullDefault){
+    //   values.push()
+    // }
+    if (this.nullDefault && !this.required) {
+      let obj = {};
+      obj[this.keyValue] = null;
+      obj[this.keyLabel] = '-- Aucun --';
+      values.unshift(obj);
+    }
     values = values
       // filter search
       .filter(
@@ -133,20 +133,34 @@ export class DatalistComponent extends GenericFormComponent implements OnInit {
       this.filteredValues.length === 1 &&
       !(this.parentFormControl.value && this.parentFormControl.value.length)
     ) {
-      const val = this.values[0][this.keyValue];
-      this.parentFormControl.patchValue(this.multiple ? [val] : val);
+      const val = this.nullDefault ? null : this.values[0][this.keyValue];
+      this.parentFormControl.patchValue(this.multiple && !this.nullDefault ? [val] : val);
     }
+
     // valeur par défaut (depuis input value)
-    if (!this.parentFormControl.value && this.default) {
+    if (
+      (!this.parentFormControl.value ||
+        (Array.isArray(this.parentFormControl.value) &&
+          this.parentFormControl.value.length == 0)) &&
+      this.default
+    ) {
       const value = this.multiple ? this.default : [this.default];
-      const res = value.map((val) =>
-        typeof val === 'object'
-          ? (this.filteredValues.find((v) =>
-              Object.keys(val).every((key) => v[key] === val[key])
-            ) || {})[this.keyValue]
-          : val
-      );
-      this.parentFormControl.patchValue(this.multiple ? res : res[0]);
+      // check if the default value is in the provided values
+      const valuesID = this.values.map((el) => el[this.keyValue]);
+      const defaultValuesID = value.map((el) => el[this.keyValue]);
+      const defaultValueIsInValues = valuesID.some((el) => defaultValuesID.includes(el));
+
+      // patch value only if default value is in values
+      if (defaultValueIsInValues) {
+        const res = value.map((val) =>
+          typeof val === 'object'
+            ? (this.filteredValues.find((v) =>
+                Object.keys(val).every((key) => v[key] === val[key])
+              ) || {})[this.keyValue]
+            : val
+        );
+        this.parentFormControl.patchValue(this.multiple ? res : res[0]);
+      }
     }
     this.parentFormControl.markAsTouched();
   }
diff --git a/frontend/src/app/GN2CommonModule/form/dynamic-form/dynamic-form.component.html b/frontend/src/app/GN2CommonModule/form/dynamic-form/dynamic-form.component.html
index 04200a1793..9d96cd8045 100644
--- a/frontend/src/app/GN2CommonModule/form/dynamic-form/dynamic-form.component.html
+++ b/frontend/src/app/GN2CommonModule/form/dynamic-form/dynamic-form.component.html
@@ -316,8 +316,15 @@
       [idMenu]="formDefComp['id_menu']"
       [idList]="formDefComp['id_list']"
       [codeList]="formDefComp['code_list']"
+      [multiSelect]="formDefComp['multi_select']"
     ></pnx-observers>
 
+    <pnx-observers-text
+      *ngSwitchCase="'observers-text'"
+      [label]="formDefComp['attribut_label']"
+      [parentFormControl]="form.get(formDefComp['attribut_name'])"
+    ></pnx-observers-text>
+
     <pnx-date
       *ngSwitchCase="'date'"
       [label]="formDefComp['attribut_label']"
@@ -356,7 +363,6 @@
       [application]="formDefComp['application']"
       [values]="formDefComp['values']"
       [api]="formDefComp['api']"
-      [values]="formDefComp['values']"
       [keyValue]="formDefComp['keyValue'] || 'value'"
       [keyLabel]="formDefComp['keyLabel'] || 'label'"
       [keyTitle]="formDefComp['keyTitle']"
@@ -369,6 +375,7 @@
       [definition]="formDefComp['definition']"
       [filters]="formDefComp['filters']"
       [default]="formDefComp['default']"
+      [nullDefault]="formDefComp['nullDefault']"
     ></pnx-datalist>
 
     <small class="form-text text-muted">{{ formDefComp['help'] }}</small>
diff --git a/frontend/src/app/GN2CommonModule/form/observers/observers.component.ts b/frontend/src/app/GN2CommonModule/form/observers/observers.component.ts
index 66e62bd5d6..9d02c18025 100644
--- a/frontend/src/app/GN2CommonModule/form/observers/observers.component.ts
+++ b/frontend/src/app/GN2CommonModule/form/observers/observers.component.ts
@@ -43,7 +43,7 @@ export class ObserversComponent extends GenericFormComponent {
   ngOnInit() {
     super.ngOnInit();
     this.bindValue = this.bindAllItem ? null : this.bindValue;
-    this.multiSelect = this.multiSelect || true;
+    this.multiSelect = this.multiSelect ? true : this.multiSelect;
     // uniformise as IdList the id of list
     // retrocompat: keep idMenu
     if (this.idList) {