diff --git a/hsmodels/schemas/aggregations.py b/hsmodels/schemas/aggregations.py
index cbfe9d0..26fda73 100644
--- a/hsmodels/schemas/aggregations.py
+++ b/hsmodels/schemas/aggregations.py
@@ -1,5 +1,5 @@
 from datetime import date
-from typing import Dict, List, Union
+from typing import Dict, List, Optional, Union
 
 from pydantic import AnyUrl, ConfigDict, Field, GetJsonSchemaHandler, model_validator, field_validator
 from pydantic.json_schema import JsonSchemaValue
@@ -61,12 +61,12 @@ class BaseAggregationMetadataIn(BaseMetadata):
         title="Additional metadata",
         description="A dictionary of additional metadata elements expressed as key-value pairs",
     )
-    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+    spatial_coverage: Optional[Union[PointCoverage, BoxCoverage]] = Field(
         default=None,
         title="Spatial coverage",
         description="An object containing the geospatial coverage for the aggregation expressed as either a bounding box or point",
     )
-    period_coverage: PeriodCoverage = Field(
+    period_coverage: Optional[PeriodCoverage] = Field(
         default=None,
         title="Temporal coverage",
         description="An object containing the temporal coverage for a aggregation expressed as a date range",
@@ -116,6 +116,11 @@ class GeographicRasterMetadataIn(BaseAggregationMetadataIn):
         title="Band information",
         description="An object containing information about the bands contained in the raster dataset",
     )
+    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+        default=None,
+        title="Spatial coverage",
+        description="An object containing the geospatial coverage for the aggregation expressed as either a bounding box or point",
+    )
     spatial_reference: Union[BoxSpatialReference, PointSpatialReference] = Field(
         default=None,
         title="Spatial reference",
@@ -142,7 +147,7 @@ class GeographicRasterMetadata(GeographicRasterMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -171,6 +176,11 @@ class GeographicFeatureMetadataIn(BaseAggregationMetadataIn):
         title="Geometry information",
         description="An object containing information about the geometry of the features in the dataset",
     )
+    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+        default=None,
+        title="Spatial coverage",
+        description="An object containing the geospatial coverage for the aggregation expressed as either a bounding box or point",
+    )
     spatial_reference: Union[BoxSpatialReference, PointSpatialReference] = Field(
         default=None,
         title="Spatial reference",
@@ -194,7 +204,7 @@ class GeographicFeatureMetadata(GeographicFeatureMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -218,12 +228,21 @@ class MultidimensionalMetadataIn(BaseAggregationMetadataIn):
         title="Variables",
         description="A list containing information about the variables for which data are stored in the dataset",
     )
+    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+        default=None,
+        title="Spatial coverage",
+        description="An object containing the geospatial coverage for the aggregation expressed as either a bounding box or point",
+    )
     spatial_reference: Union[MultidimensionalBoxSpatialReference, MultidimensionalPointSpatialReference] = Field(
         default=None,
         title="Spatial reference",
         description="An object containing spatial reference information for the dataset",
     )
-
+    period_coverage: PeriodCoverage = Field(
+        default=None,
+        title="Temporal coverage",
+        description="An object containing the temporal coverage for a aggregation expressed as a date range",
+    )
     _parse_spatial_reference = field_validator("spatial_reference", mode='before')(
         parse_multidimensional_spatial_reference
     )
@@ -243,7 +262,7 @@ class MultidimensionalMetadata(MultidimensionalMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -278,7 +297,7 @@ class ReferencedTimeSeriesMetadata(ReferencedTimeSeriesMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -313,7 +332,7 @@ class FileSetMetadata(FileSetMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -347,7 +366,7 @@ class SingleFileMetadata(SingleFileMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -375,7 +394,17 @@ class TimeSeriesMetadataIn(BaseAggregationMetadataIn):
         description="A list of time series results contained within the time series aggregation",
     )
 
-    abstract: str = Field(default=None, title="Abstract", description="A string containing a summary of a aggregation")
+    abstract: Optional[str] = Field(default=None, title="Abstract", description="A string containing a summary of a aggregation")
+    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+        default=None,
+        title="Spatial coverage",
+        description="An object containing the geospatial coverage for the aggregation expressed as either a bounding box or point",
+    )
+    period_coverage: PeriodCoverage = Field(
+        default=None,
+        title="Temporal coverage",
+        description="An object containing the temporal coverage for a aggregation expressed as a date range",
+    )
 
     _parse_abstract = model_validator(mode='before')(parse_abstract)
 
@@ -394,7 +423,7 @@ class TimeSeriesMetadata(TimeSeriesMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -410,7 +439,7 @@ class ModelProgramMetadataIn(BaseAggregationMetadataIn):
 
     model_config = ConfigDict(title="Model Program Aggregation Metadata")
 
-    version: str = Field(
+    version: Optional[str] = Field(
         default=None, title="Version", description="The software version or build number of the model", max_length=255
     )
 
@@ -428,17 +457,17 @@ class ModelProgramMetadataIn(BaseAggregationMetadataIn):
         description="Compatible operating systems to setup and run the model",
     )
 
-    release_date: date = Field(
+    release_date: Optional[date] = Field(
         default=None, title="Release Date", description="The date that this version of the model was released"
     )
 
-    website: AnyUrl = Field(
+    website: Optional[AnyUrl] = Field(
         default=None,
         title='Website',
         description='A URL to a website describing the model that is maintained by the model developers',
     )
 
-    code_repository: AnyUrl = Field(
+    code_repository: Optional[AnyUrl] = Field(
         default=None,
         title='Software Repository',
         description='A URL to the source code repository for the model code (e.g., git, mercurial, svn, etc.)',
@@ -448,7 +477,7 @@ class ModelProgramMetadataIn(BaseAggregationMetadataIn):
         default=[], title='File Types', description='File types used by the model program'
     )
 
-    program_schema_json: AnyUrl = Field(
+    program_schema_json: Optional[AnyUrl] = Field(
         default=None,
         title='Model program schema',
         description='A url to the JSON metadata schema for the model program',
@@ -471,7 +500,7 @@ class ModelProgramMetadata(ModelProgramMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
@@ -492,19 +521,19 @@ class ModelInstanceMetadataIn(BaseAggregationMetadataIn):
         description="Indicates whether model output files are included in the aggregation",
     )
 
-    executed_by: AnyUrl = Field(
+    executed_by: Optional[AnyUrl] = Field(
         default=None,
         title="Executed By",
         description="A URL to the Model Program that can be used to execute this model instance",
     )
 
-    program_schema_json: AnyUrl = Field(
+    program_schema_json: Optional[AnyUrl] = Field(
         default=None,
         title="JSON Metadata schema URL",
         description="A URL to the JSON metadata schema for the related model program",
     )
 
-    program_schema_json_values: AnyUrl = Field(
+    program_schema_json_values: Optional[AnyUrl] = Field(
         default=None,
         title="JSON metadata schema values URL",
         description="A URL to a JSON file containing the metadata values conforming to the JSON metadata schema for the related model program",
@@ -525,7 +554,7 @@ class ModelInstanceMetadata(ModelInstanceMetadataIn):
         json_schema_extra={"readOnly": True},
     )
 
-    rights: Rights = Field(
+    rights: Optional[Rights] = Field(
         default=None,
         title="Rights statement",
         description="An object containing information about the rights held in and over the aggregation and the license under which a aggregation is shared",
diff --git a/hsmodels/schemas/base_models.py b/hsmodels/schemas/base_models.py
index 58bff3d..4018dde 100644
--- a/hsmodels/schemas/base_models.py
+++ b/hsmodels/schemas/base_models.py
@@ -1,6 +1,7 @@
 from datetime import datetime
-from typing import Any, Dict, Union
+from typing import Any, Literal, Union
 
+import typing_extensions
 from pydantic import BaseModel, ConfigDict
 
 
@@ -8,14 +9,17 @@ class BaseMetadata(BaseModel):
     def model_dump(
         self,
         *,
-        include: Union['AbstractSetIntStr', 'MappingIntStrAny'] = None,
-        exclude: Union['AbstractSetIntStr', 'MappingIntStrAny'] = None,
+        mode: Union[typing_extensions.Literal['json', 'python'], str] = 'python',
+        include: 'IncEx' = None,
+        exclude: 'IncEx' = None,
+        context: Union[dict[str, Any], None] = None,
         by_alias: bool = False,
         exclude_unset: bool = False,
         exclude_defaults: bool = False,
         exclude_none: bool = True,
         round_trip: bool = False,
-        warnings: bool = False,
+        warnings: Union[bool, Literal['none', 'warn', 'error']] = False,
+        serialize_as_any: bool = False,
         to_rdf: bool = False,
     ) -> dict[str, Any]:
         """
@@ -28,14 +32,17 @@ def model_dump(
         Override the default of exclude_none to True
         """
         d = super().model_dump(
+            mode=mode,
             include=include,
             exclude=exclude,
+            context=context,
             by_alias=by_alias,
             exclude_unset=exclude_unset,
             exclude_defaults=exclude_defaults,
             exclude_none=exclude_none,
             round_trip=round_trip,
             warnings=warnings,
+            serialize_as_any=serialize_as_any,
         )
         if to_rdf and "additional_metadata" in d:
             additional_metadata = d["additional_metadata"]
@@ -47,14 +54,16 @@ def model_dump_json(
         self,
         *,
         indent: Union[int, None] = None,
-        include: Union['AbstractSetIntStr', 'MappingIntStrAny'] = None,
-        exclude: Union['AbstractSetIntStr', 'MappingIntStrAny'] = None,
+        include: 'IncEx' = None,
+        exclude: 'IncEx' = None,
+        context: Union[dict[str, Any], None] = None,
         by_alias: bool = False,
         exclude_unset: bool = False,
         exclude_defaults: bool = False,
         exclude_none: bool = True,
         round_trip: bool = False,
-        warnings: bool = False,
+        warnings: Union[bool, Literal['none', 'warn', 'error']] = False,
+        serialize_as_any: bool = False,
     ) -> str:
         """
         Generate a JSON representation of the model, `include` and `exclude` arguments as per `dict()`.
@@ -67,12 +76,14 @@ def model_dump_json(
             indent=indent,
             include=include,
             exclude=exclude,
+            context=context,
             by_alias=by_alias,
             exclude_unset=exclude_unset,
             exclude_defaults=exclude_defaults,
             exclude_none=exclude_none,
             round_trip=round_trip,
             warnings=warnings,
+            serialize_as_any=serialize_as_any,
         )
 
     model_config = ConfigDict(validate_assignment=True)
diff --git a/hsmodels/schemas/fields.py b/hsmodels/schemas/fields.py
index b7731a3..cd1230e 100644
--- a/hsmodels/schemas/fields.py
+++ b/hsmodels/schemas/fields.py
@@ -130,22 +130,22 @@ class Creator(BaseMetadata):
     name: str = Field(
         default=None, max_length=100, title="Name", description="A string containing the name of the creator"
     )
-    phone: str = Field(
+    phone: Optional[str] = Field(
         default=None, max_length=25, title="Phone", description="A string containing a phone number for the creator"
     )
-    address: str = Field(
+    address: Optional[str] = Field(
         default=None, max_length=250, title="Address", description="A string containing an address for the creator"
     )
-    organization: str = Field(
+    organization: Optional[str] = Field(
         default=None,
         max_length=200,
         title="Organization",
         description="A string containing the name of the organization with which the creator is affiliated",
     )
-    email: EmailStr = Field(
+    email: Optional[EmailStr] = Field(
         default=None, title="Email", description="A string containing an email address for the creator"
     )
-    homepage: HttpUrl = Field(
+    homepage: Optional[HttpUrl] = Field(
         default=None,
         title="Homepage",
         description="An object containing the URL for website associated with the creator",
@@ -156,7 +156,7 @@ class Creator(BaseMetadata):
         description="An integer to order creators",
         frozen=True,
     )
-    hydroshare_user_id: int = Field(
+    hydroshare_user_id: Optional[int] = Field(
         default=None,
         title="Hydroshare user id",
         description="An integer containing the Hydroshare user ID",
@@ -191,26 +191,26 @@ class Contributor(BaseMetadata):
     model_config = ConfigDict(title='Contributor Metadata')
 
     name: str = Field(default=None, title="Name", description="A string containing the name of the contributor")
-    phone: str = Field(
+    phone: Optional[str] = Field(
         default=None, title="Phone", description="A string containing a phone number for the contributor"
     )
-    address: str = Field(
+    address: Optional[str] = Field(
         default=None, title="Address", description="A string containing an address for the contributor"
     )
-    organization: str = Field(
+    organization: Optional[str] = Field(
         default=None,
         title="Organization",
         description="A string containing the name of the organization with which the contributor is affiliated",
     )
-    email: EmailStr = Field(
+    email: Optional[EmailStr] = Field(
         default=None, title="Email", description="A string containing an email address for the contributor"
     )
-    homepage: HttpUrl = Field(
+    homepage: Optional[HttpUrl] = Field(
         default=None,
         title="Homepage",
         description="An object containing the URL for website associated with the contributor",
     )
-    hydroshare_user_id: int = Field(
+    hydroshare_user_id: Optional[int] = Field(
         default=None,
         title="Hyroshare user id",
         description="An integer containing the Hydroshare user ID",
@@ -251,13 +251,13 @@ class AwardInfo(BaseMetadata):
     funding_agency_name: str = Field(
         title="Agency name", description="A string containing the name of the funding agency or organization",
     )
-    title: str = Field(
+    title: Optional[str] = Field(
         default=None, title="Award title", description="A string containing the title of the project or award",
     )
-    number: str = Field(
+    number: Optional[str] = Field(
         default=None, title="Award number", description="A string containing the award number or other identifier",
     )
-    funding_agency_url: AnyUrl = Field(
+    funding_agency_url: Optional[AnyUrl] = Field(
         default=None,
         title="Agency URL",
         description="An object containing a URL pointing to a website describing the funding award",
@@ -273,37 +273,37 @@ class BandInformation(BaseMetadata):
 
     name: str = Field(max_length=500, title="Name", description="A string containing the name of the raster band",
                       )
-    variable_name: str = Field(
+    variable_name: Optional[str] = Field(
         default=None,
         max_length=100,
         title="Variable name",
         description="A string containing the name of the variable represented by the raster band",
     )
-    variable_unit: str = Field(
+    variable_unit: Optional[str] = Field(
         default=None,
         max_length=50,
         title="Variable unit",
         description="A string containing the units for the raster band variable",
     )
-    no_data_value: str = Field(
+    no_data_value: Optional[str] = Field(
         default=None,
         title="Nodata value",
         description="A string containing the numeric nodata value for the raster band",
     )
-    maximum_value: str = Field(
+    maximum_value: Optional[str] = Field(
         default=None,
         title="Maximum value",
         description="A string containing the maximum numeric value for the raster band",
     )
-    comment: str = Field(
+    comment: Optional[str] = Field(
         default=None, title="Comment", description="A string containing a comment about the raster band",
     )
-    method: str = Field(
+    method: Optional[str] = Field(
         default=None,
         title="Method",
         description="A string containing a description of the method used to create the raster band data",
     )
-    minimum_value: str = Field(
+    minimum_value: Optional[str] = Field(
         default=None,
         title="Minimum value",
         description="A string containing the minimum numerica value for the raster dataset",
@@ -326,16 +326,16 @@ class FieldInformation(BaseMetadata):
     )
     # TODO: What is the "field_type_code"? It's not displayed on the resource landing page, but it's encoded in the
     #  aggregation metadata as an integer value.
-    field_type_code: str = Field(
+    field_type_code: Optional[str] = Field(
         default=None,
         max_length=50,
         title="Field type code",
         description="A string value containing a code that indicates the field type",
     )
-    field_width: int = Field(
+    field_width: Optional[int] = Field(
         default=None, title="Field width", description="An integer value containing the width of the attribute field",
     )
-    field_precision: int = Field(
+    field_precision: Optional[int] = Field(
         default=None,
         title="Field precision",
         description="An integer value containing the precision of the attribute field",
@@ -383,18 +383,18 @@ class Variable(BaseMetadata):
         title="Shape",
         description="A string containing the shape of the variable expressed as a list of dimensions",
     )
-    descriptive_name: str = Field(
+    descriptive_name: Optional[str] = Field(
         default=None,
         max_length=1000,
         title="Descriptive name",
         description="A string containing a descriptive name for the variable",
     )
-    method: str = Field(
+    method: Optional[str] = Field(
         default=None,
         title="Method",
         description="A string containing a description of the method used to create the values for the variable",
     )
-    missing_value: str = Field(
+    missing_value: Optional[str] = Field(
         default=None,
         max_length=1000,
         title="Missing value",
@@ -442,13 +442,13 @@ class TimeSeriesVariable(BaseMetadata):
     #  It is an integer in the HydroShare database, so will have to be updated there as well if changed
     no_data_value: int = Field(title="NoData value", description="The NoData value for the variable",
                                )
-    variable_definition: str = Field(
+    variable_definition: Optional[str] = Field(
         default=None,
         max_length=255,
         title="Variable definition",
         description="A string containing a detailed description of the variable",
     )
-    speciation: str = Field(
+    speciation: Optional[str] = Field(
         default=None,
         max_length=255,
         title="Speciation",
@@ -468,32 +468,32 @@ class TimeSeriesSite(BaseMetadata):
         title="Site code",
         description="A string containing a short but meaningful code identifying the site",
     )
-    site_name: str = Field(
+    site_name: Optional[str] = Field(
         default=None, max_length=255, title="Site name", description="A string containing the name of the site",
     )
-    elevation_m: float = Field(
+    elevation_m: Optional[float] = Field(
         default=None,
         title="Elevation",
         description="A floating point number expressing the elevation of the site in meters",
     )
-    elevation_datum: str = Field(
+    elevation_datum: Optional[str] = Field(
         default=None,
         max_length=50,
         title="Elevation datum",
         description="A string expressing the elevation datum used from the ODM2 Elevation Datum controlled vocabulary",
     )
-    site_type: str = Field(
+    site_type: Optional[str] = Field(
         default=None,
         max_length=100,
         title="Site type",
         description="A string containing the type of site from the ODM2 Sampling Feature Type controlled vocabulary ",
     )
-    latitude: float = Field(
+    latitude: Optional[float] = Field(
         default=None,
         title="Latitude",
         description="A floating point value expressing the latitude coordinate of the site",
     )
-    longitude: float = Field(
+    longitude: Optional[float] = Field(
         default=None,
         title="Longitude",
         description="A floating point value expressing the longitude coordinate of the site",
@@ -520,11 +520,11 @@ class TimeSeriesMethod(BaseMetadata):
         title="Method type",
         description="A string containing the method type from the ODM2 Method Type controlled vocabulary",
     )
-    method_description: str = Field(
+    method_description: Optional[str] = Field(
         default=None, title="Method description",
         description="A string containing a detailed description of the method",
     )
-    method_link: AnyUrl = Field(
+    method_link: Optional[AnyUrl] = Field(
         default=None,
         title="Method link",
         description="An object containing a URL that points to a website having a detailed description of the method",
@@ -544,13 +544,13 @@ class ProcessingLevel(BaseMetadata):
         title="Processing level code",
         description="A string containing a short but meaningful code identifying the processing level",
     )
-    definition: str = Field(
+    definition: Optional[str] = Field(
         default=None,
         max_length=200,
         title="Definition",
         description="A string containing a description of the processing level",
     )
-    explanation: str = Field(
+    explanation: Optional[str] = Field(
         default=None,
         title="Explanation",
         description="A string containing a more extensive explanation of the meaning of the processing level",
@@ -612,7 +612,7 @@ class TimeSeriesResult(BaseMetadata):
         title="Units",
         description="An object containing the units in which the values of the time series are expressed",
     )
-    status: str = Field(
+    status: Optional[str] = Field(
         default=None,
         max_length=255,
         title="Status",
@@ -646,7 +646,7 @@ class TimeSeriesResult(BaseMetadata):
         description="An object containing metadata about the site at which the time series result was created",
     )
     variable: TimeSeriesVariable = Field(
-        title="Variablef",
+        title="Variable",
         description="An object containing metadata about the observed variable associated with the time series result values",
     )
     method: TimeSeriesMethod = Field(
@@ -657,7 +657,7 @@ class TimeSeriesResult(BaseMetadata):
         title="Processing level",
         description="An object containing metadata about the processing level or level of quality control to which the time series result values have been subjected",
     )
-    utc_offset: float = Field(
+    utc_offset: Optional[float] = Field(
         default=None,
         title="UTC Offset",
         description="A floating point value that represents the time offset from UTC time in hours associated with the time series result value timestamps",
diff --git a/hsmodels/schemas/resource.py b/hsmodels/schemas/resource.py
index 852684f..9538b56 100644
--- a/hsmodels/schemas/resource.py
+++ b/hsmodels/schemas/resource.py
@@ -1,5 +1,5 @@
 from datetime import datetime
-from typing import Dict, List, Union, Literal
+from typing import Dict, List, Union, Literal, Optional
 
 from pydantic import AnyUrl, ConfigDict, Field, GetJsonSchemaHandler, field_validator, model_validator
 from pydantic.json_schema import JsonSchemaValue
@@ -78,12 +78,12 @@ class ResourceMetadataIn(BaseMetadata):
         title="Funding agency information",
         description="A list of objects containing information about the funding agencies and awards associated with a resource",
     )
-    spatial_coverage: Union[PointCoverage, BoxCoverage] = Field(
+    spatial_coverage: Optional[Union[PointCoverage, BoxCoverage]] = Field(
         default=None,
         title="Spatial coverage",
         description="An object containing information about the spatial topic of a resource, the spatial applicability of a resource, or jurisdiction under with a resource is relevant",
     )
-    period_coverage: PeriodCoverage = Field(
+    period_coverage: Optional[PeriodCoverage] = Field(
         default=None,
         title="Temporal coverage",
         description="An object containing information about the temporal topic or applicability of a resource",
diff --git a/requirements.txt b/requirements.txt
index cdf0952..b01dd2e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 rdflib<6.0.0
-pydantic==2.*
+pydantic==2.7.*
 email-validator
 jsonschema2md
 black
diff --git a/setup.py b/setup.py
index e588049..42b28de 100644
--- a/setup.py
+++ b/setup.py
@@ -4,12 +4,12 @@
 
 setup(
     name='hsmodels',
-    version='1.0.0',
+    version='1.0.1',
     packages=find_packages(include=['hsmodels', 'hsmodels.*', 'hsmodels.schemas.*', 'hsmodels.schemas.rdf.*'],
                            exclude=("tests",)),
     install_requires=[
         'rdflib<6.0.0',
-        'pydantic==2.*',
+        'pydantic==2.7.*',
         'email-validator'
     ],
     url='https://github.com/hydroshare/hsmodels',
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index a35b47a..9ae85ed 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -86,6 +86,9 @@ def test_resource_metadata(res_md):
     assert "key2" in res_md.additional_metadata
     assert res_md.additional_metadata["key2"] == "value2"
 
+    # test additional_metadata can be optional
+    res_md.additional_metadata = {}
+
     assert len(res_md.creators) == 3
     for cr in res_md.creators:
         assert cr.creator_order in (1, 2, 3)
@@ -119,12 +122,18 @@ def test_resource_metadata(res_md):
     assert str(contributor.identifiers[UserIdentifierType.ORCID]) == "https://orcid.org/0000-0002-1998-3479"
     assert contributor.name == "David Tarboton"
 
+    # test contributor can be optional
+    res_md.contributors = []
+
     assert len(res_md.relations) == 3
     assert any(x for x in res_md.relations if x.value == "https://sadf.com" and x.type == RelationType.isPartOf)
     assert any(
         x for x in res_md.relations if x.value == "https://www.google.com/" and x.type == RelationType.isCreatedBy
     )
 
+    # test relation can be optional
+    res_md.relations = []
+
     assert res_md.rights.statement == "my statement"
     assert str(res_md.rights.url) == "http://studio.bakajo.com/"
 
@@ -139,10 +148,14 @@ def test_resource_metadata(res_md):
     assert award.number == "n"
     assert award.funding_agency_name == "agency1"
     assert str(award.funding_agency_url) == "https://google.com/"
+    # test awards can be optional
+    res_md.awards = []
 
     assert res_md.period_coverage == PeriodCoverage(
         start=datetime.fromisoformat("2020-07-10T00:00:00"), end=datetime.fromisoformat("2020-07-29T00:00:00")
     )
+    # test period_coverage can be optional
+    res_md.period_coverage = None
 
     assert res_md.spatial_coverage == BoxCoverage(
         name="asdfsadf",
@@ -165,6 +178,8 @@ def test_resource_metadata(res_md):
     )
 
     res_md.spatial_coverage = pc
+    # test spatial_coverage can be optional
+    res_md.spatial_coverage = None
 
     assert res_md.publisher
     assert (
diff --git a/tests/test_metadata_json.py b/tests/test_metadata_json.py
index 7409b43..31d88a3 100644
--- a/tests/test_metadata_json.py
+++ b/tests/test_metadata_json.py
@@ -66,3 +66,127 @@ def test_metadata_json_serialization(metadata_json_input):
     from_file = sorting(json.loads(json_file_str))
     for i in range(1, len(from_file)):
         assert from_file[i] == from_schema[i]
+
+
+def test_optional_fields_resource():
+    with open("data/json/resource.json", 'r') as f:
+        md = ResourceMetadataIn(**json.loads(f.read()))
+    # test period_coverage is optional
+    md.period_coverage = None
+    # test spatial_coverage is optional
+    md.spatial_coverage = None
+    # test contributor is optional
+    md.contributors = []
+    # test relation is optional
+    md.relations = []
+    # test additional_metadata is optional
+    md.additional_metadata = {}
+    # test awards is optional
+    md.awards = []
+    # test subjects is optional
+    md.subjects = []
+
+
+def test_optional_fields_raster_aggr():
+    with open("data/json/geographicraster.json", 'r') as f:
+        md = GeographicRasterMetadataIn(**json.loads(f.read()))
+    # test period_coverage is optional
+    md.period_coverage = None
+    # test some of the fields of the band_information are optional
+    md.band_information.variable_name = None
+    md.band_information.variable_unit = None
+    md.band_information.maximum_value = None
+    md.band_information.minimum_value = None
+    md.band_information.no_data_value = None
+    md.band_information.comment = None
+    md.band_information.method = None
+
+
+def test_optional_fields_geo_feature_aggr():
+    with open("data/json/geographicfeature.json", 'r') as f:
+        md = GeographicFeatureMetadataIn(**json.loads(f.read()))
+    # test period_coverage is optional
+    md.period_coverage = None
+
+    # test some of the fields of the field_information are optional
+    md.field_information[0].field_type_code = None
+    md.field_information[0].field_width = None
+    md.field_information[0].field_precision = None
+
+
+def test_optional_fields_multidimensional_aggr():
+    with open("data/json/multidimensional.json", 'r') as f:
+        md = MultidimensionalMetadataIn(**json.loads(f.read()))
+    # test variable optional attributes
+    md.variables[0].method = None
+    md.variables[0].descriptive_name = None
+    md.variables[0].missing_value = None
+
+
+def test_optional_fields_fileset_aggr():
+    with open("data/json/fileset.json", 'r') as f:
+        md = FileSetMetadataIn(**json.loads(f.read()))
+    # test spatial_coverage is optional
+    md.spatial_coverage = None
+    # test period_coverage is optional
+    md.period_coverage = None
+
+
+def test_optional_fields_singlefile_aggr():
+    with open("data/json/singlefile.json", 'r') as f:
+        md = SingleFileMetadataIn(**json.loads(f.read()))
+    # test spatial_coverage is optional
+    md.spatial_coverage = None
+    # test period_coverage is optional
+    md.period_coverage = None
+
+
+def test_optional_fields_timeseries_aggr():
+    with open("data/json/timeseries.json", 'r') as f:
+        md = TimeSeriesMetadataIn(**json.loads(f.read()))
+
+    # test some of the fields of the variable are optional
+    md.time_series_results[0].variable.variable_definition = None
+    md.time_series_results[0].variable.speciation = None
+
+    # test some of the fields of the site are optional
+    md.time_series_results[0].site.site_name = None
+    md.time_series_results[0].site.elevation_m = None
+    md.time_series_results[0].site.elevation_datum = None
+    md.time_series_results[0].site.site_type = None
+    md.time_series_results[0].site.latitude = None
+    md.time_series_results[0].site.longitude = None
+
+    # test some of the fields of the method are optional
+    md.time_series_results[0].method.method_description = None
+    md.time_series_results[0].method.method_link = None
+
+    # test some of the fields of the processing_level are optional
+    md.time_series_results[0].processing_level.definition = None
+    md.time_series_results[0].processing_level.explanation = None
+
+
+def test_optional_fields_modelprogram_aggr():
+    with open("data/json/modelprogram.json", 'r') as f:
+        md = ModelProgramMetadataIn(**json.loads(f.read()))
+    # test version is optional
+    md.version = None
+    # test release_date is optional
+    md.release_date = None
+    # test website is optional
+    md.website = None
+    # test code_repository is optional
+    md.code_repository = None
+    # test program_schema_json is optional
+    md.program_schema_json = None
+
+
+def test_optional_fields_modelinstance_aggr():
+    with open("data/json/modelinstance.json", 'r') as f:
+        md = ModelInstanceMetadataIn(**json.loads(f.read()))
+    # test executed_by is optional
+    md.executed_by = None
+    # test program_schema_json is optional
+    md.program_schema_json = None
+    # test program_schema_json_values is optional
+    md.program_schema_json_values = None
diff --git a/tests/test_validation.py b/tests/test_validation.py
index 6e361b1..d5fc4f7 100644
--- a/tests/test_validation.py
+++ b/tests/test_validation.py
@@ -327,7 +327,7 @@ def test_aggregation_metadata_from_form():
             "units": "Decimal degrees",
             "projection": "WGS 84 EPSG:4326",
         },
-        # "period_coverage": None,
+        "period_coverage": None,
         "rights": {
             "statement": "This resource is shared under the Creative Commons Attribution CC BY.",
             "url": "http://creativecommons.org/licenses/by/4.0/",
@@ -335,12 +335,12 @@ def test_aggregation_metadata_from_form():
         "type": "GeoRaster",
         "band_information": {
             "name": "Band_1",
-            # "variable_name": None,
-            # "variable_unit": None,
+            "variable_name": None,
+            "variable_unit": None,
             "no_data_value": "-3.40282346639e+38",
             "maximum_value": "2880.00708008",
-            # "comment": None,
-            # "method": None,
+            "comment": None,
+            "method": None,
             "minimum_value": "2274.95898438",
         },
         "spatial_reference": {
@@ -384,13 +384,6 @@ def test_subjects_aggregation(agg_md):
 
 
 def test_default_exclude_none(res_md):
-    # TODO: we can't do the following assignment unless we change the schema for spatial_coverage
-    #  to Optional[Union[PointCoverage, BoxCoverage]]
-    # res_md.spatial_coverage = None
-    assert "spatial_coverage" in res_md.model_dump()
-    model_data = res_md.model_dump()
-
-    # remove spatial_coverage from input data
-    model_data.pop("spatial_coverage")
-    res_md = type(res_md)(**model_data)
+    res_md.spatial_coverage = None
+    assert "spatial_coverage" not in res_md.model_dump()
     assert "spatial_coverage" in res_md.model_dump(exclude_none=False)