diff --git a/NAMESPACE b/NAMESPACE
index 29072cd..f831d3e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -6,16 +6,21 @@ export(get_tiles_path)
 export(is_tile_existing)
 export(lfa_capitalize_first_char)
 export(lfa_check_flag)
+export(lfa_combine_sf_obj)
 export(lfa_create_stacked_distributions_plot)
 export(lfa_create_stacked_histogram)
 export(lfa_create_tile_location_objects)
 export(lfa_detection)
 export(lfa_download)
 export(lfa_download_areas)
+export(lfa_find_n_nearest_trees)
 export(lfa_get_all_areas)
 export(lfa_get_detection_area)
+export(lfa_get_detections)
 export(lfa_get_detections_species)
 export(lfa_get_flag_path)
+export(lfa_get_neighbor_paths)
+export(lfa_get_species)
 export(lfa_ground_correction)
 export(lfa_init)
 export(lfa_init_data_structure)
@@ -23,9 +28,11 @@ export(lfa_intersect_areas)
 export(lfa_load_ctg_if_not_present)
 export(lfa_map_tile_locations)
 export(lfa_merge_and_save)
+export(lfa_modify_gpkg)
 export(lfa_rd_to_qmd)
 export(lfa_rd_to_results)
 export(lfa_read_area_as_catalog)
+export(lfa_save_all_neighbours)
 export(lfa_segmentation)
 export(lfa_set_flag)
 export(read_catalog)
diff --git a/R/combine_sf_obj.R b/R/combine_sf_obj.R
new file mode 100644
index 0000000..e6169d5
--- /dev/null
+++ b/R/combine_sf_obj.R
@@ -0,0 +1,31 @@
+#' Combine Spatial Feature Objects from Multiple GeoPackage Files
+#'
+#' This function reads spatial feature objects (sf) from multiple GeoPackage files and combines them into a single sf object.
+#' Each GeoPackage file is assumed to contain neighbor information for a specific detection area, and the resulting sf object
+#' includes additional columns indicating the corresponding area and species information.
+#'
+#' @param paths A character vector containing file paths to GeoPackage files with neighbor information.
+#' @param area_infos A data frame or list containing information about the corresponding detection areas, including "area" and "specie" columns.
+#' @return A combined sf object with additional columns for area and specie information.
+#' @export
+#'
+#' @examples
+#' # Assuming paths and area_infos are defined
+#' combined_sf <- lfa_combine_sf_obj(paths, area_infos)
+#'
+#' # Print the combined sf object
+#' print(combined_sf)
+#'
+#'@export
+lfa_combine_sf_obj <- function(paths, area_infos) {
+  sf_obj <- sf::st_read(paths[1])
+  sf_obj$area = area_infos$area[1]
+  sf_obj$specie = area_infos$specie[1]
+  for (i in 2:length(paths)) {
+    extend <- sf::st_read(paths[i])
+    extend$area = area_infos$area[i]
+    extend$specie = area_infos$specie[i]
+    sf_obj <- dplyr::bind_rows(sf_obj, extend)
+  }
+  return(sf_obj)
+}
diff --git a/R/find_n_nearest_trees.R b/R/find_n_nearest_trees.R
new file mode 100644
index 0000000..295474f
--- /dev/null
+++ b/R/find_n_nearest_trees.R
@@ -0,0 +1,48 @@
+#' Find n Nearest Trees
+#'
+#' This function calculates the distances to the n nearest trees for each tree in the input dataset.
+#'
+#' @param trees A sf object containing tree coordinates.
+#' @param n The number of nearest trees to find for each tree (default is 100).
+#' @return A data frame with additional columns representing the distances to the n nearest trees.
+#'
+#' @examples
+#' # Load tree data using lfa_get_detections() (not provided)
+#' tree_data <- lfa_get_detections()
+#'
+#' # Filter tree data for a specific species and area
+#' tree_data = tree_data[tree_data$specie == "pine" & tree_data$area == "greffen", ]
+#'
+#' # Find the 100 nearest trees for each tree in the filtered dataset
+#' tree_data <- lfa_find_n_nearest_trees(tree_data)
+#'
+#'@export
+lfa_find_n_nearest_trees <- function(trees, n = 100) {
+  coordinates <- sf::st_coordinates(trees)
+
+  distances_matrix <- matrix(NA, nrow = nrow(coordinates), ncol = n)
+
+  cat("Calculate ", nrow(coordinates), "entries")
+  for (i in seq_len(nrow(coordinates))) {
+    query_point <- coordinates[i,]
+    neighbors <-
+      spdep::knn2nb(spdep::knearneigh(coordinates, k = n))
+
+    # Extract the coordinates of neighbors and create an sf object
+    neighbor_indices <- unlist(neighbors[[i]])
+    neighbors_sf <- trees[neighbor_indices,]
+
+    # Set CRS for query point
+    query_point_sf <-
+      sf::st_sfc(sf::st_point(c(query_point[1], query_point[2])), crs = sf::st_crs(trees))
+
+    distances <- sf::st_distance(query_point_sf, neighbors_sf)
+    distances <- distances[order(distances)]
+    distances_matrix[i, ] <- distances
+    cat(i, "/", nrow(coordinates), "\n")
+  }
+  distances_matrix <- distances_matrix |> data.frame()
+  colnames(distances_matrix) <- paste0("Neighbor_", 1:n)
+  trees <- dplyr::bind_cols(trees, distances_matrix)
+  return(trees)
+}
diff --git a/R/get_detections.R b/R/get_detections.R
new file mode 100644
index 0000000..df4d09c
--- /dev/null
+++ b/R/get_detections.R
@@ -0,0 +1,43 @@
+#' Retrieve aggregated detection data for multiple species.
+#'
+#' This function obtains aggregated detection data for multiple species by iterating
+#' through the list of species obtained from \code{\link{lfa_get_species}}. For each
+#' species, it calls \code{\link{lfa_get_detections_species}} to retrieve the
+#' corresponding detection data and aggregates the results into a single data frame.
+#' The resulting data frame includes columns for the species, tree detection data,
+#' and the area in which the detections occurred.
+#'
+#' @return A data frame containing aggregated detection data for multiple species.
+#'
+#' @export
+#' @seealso
+#' \code{\link{lfa_get_species}}, \code{\link{lfa_get_detections_species}}
+#'
+#' @examples
+#' lfa_get_detections()
+#'
+#' @keywords data manipulation aggregation
+#'
+#' @family data retrieval functions
+#'
+#' @examples
+#' # Retrieve aggregated detection data for multiple species
+#' detections_data <- lfa_get_detections()
+#'
+#' @export
+lfa_get_detections <- function() {
+  species <- lfa_get_species()
+  results <- NULL
+  for(specie in species){
+    trees <- lfa_get_detections_species(specie)
+    trees$specie <- specie
+    if(is.null(results)){
+      results <- trees
+    } else {
+      results <- dplyr::bind_rows(results, trees)
+    }
+  }
+  results$area <- as.factor(results$area)
+  results$specie <- as.factor(results$specie)
+  return(results)
+}
diff --git a/R/get_neighbor_paths.R b/R/get_neighbor_paths.R
new file mode 100644
index 0000000..803a539
--- /dev/null
+++ b/R/get_neighbor_paths.R
@@ -0,0 +1,25 @@
+#' Get Paths to Neighbor GeoPackage Files
+#'
+#' This function retrieves the file paths to GeoPackage files containing neighbor information for each detection area.
+#' The GeoPackage files are assumed to be named "neighbours.gpkg" and organized in a directory structure under the "data" folder.
+#'
+#' @return A character vector containing file paths to GeoPackage files for each detection area's neighbors.
+#' @export
+#'
+#' @examples
+#' # Get paths to neighbor GeoPackage files for all areas
+#' paths <- lfa_get_neighbor_paths()
+#'
+#' # Print the obtained file paths
+#' print(paths)
+#'@export
+lfa_get_neighbor_paths <- function() {
+  all_areas <- lfa::lfa_get_all_areas()
+  return(file.path(
+    getwd(),
+    "data",
+    all_areas$specie,
+    all_areas$area,
+    "neighbours.gpkg"
+  ))
+}
diff --git a/R/get_species.R b/R/get_species.R
new file mode 100644
index 0000000..7baaa41
--- /dev/null
+++ b/R/get_species.R
@@ -0,0 +1,25 @@
+#' Get a list of species from the data directory.
+#'
+#' This function retrieves a list of species by scanning the "data" directory
+#' located in the current working directory.
+#'
+#' @return A character vector containing the names of species found in the "data" directory.
+#'
+#' @seealso
+#' \code{\link{list.dirs}}
+#'
+#' @references
+#' This function relies on the \code{\link{list.dirs}} function for directory listing.
+#'
+#' @keywords data manipulation file system
+#'
+#' @family data retrieval functions
+#'
+#' @examples
+#' # Retrieve the list of species
+#' species_list <- lfa_get_species()
+#'
+#' @export
+lfa_get_species <- function() {
+  return(file.path(getwd(), "data") |> list.dirs(full.names = FALSE, recursive = FALSE))
+}
diff --git a/R/save_all_neighbours.R b/R/save_all_neighbours.R
new file mode 100644
index 0000000..166a396
--- /dev/null
+++ b/R/save_all_neighbours.R
@@ -0,0 +1,24 @@
+#' Save Neighbors for All Areas
+#'
+#' This function iterates through all detection areas, finds the n nearest trees for each tree,
+#' and saves the result to a GeoPackage file for each area.
+#'
+#' @param n The number of nearest trees to find for each tree (default is 100).
+#' @export
+#'
+#' @examples
+#' # Save neighbors for all areas with default value (n=100)
+#' lfa_save_all_neighbours()
+#'
+#' # Save neighbors for all areas with a specific value of n (e.g., n=50)
+#' lfa_save_all_neighbours(n = 50)
+#' @export
+lfa_save_all_neighbours <- function (n = 100) {
+  all_areas <- lfa::lfa_get_all_areas()
+  for (i in 1:nrow(all_areas)) {
+    cat("Find neighbours for", all_areas[i, 1], ",", all_areas[i, 2], "\n")
+    out_path <-
+      file.path(getwd(), "data", all_areas[i, 1], all_areas[i, 2], "neighbours.gpkg")
+    lfa::lfa_get_detection_area(all_areas[i, 1], all_areas[i, 2]) |> lfa::lfa_find_n_nearest_trees(n) |> sf::st_write(out_path, append = F)
+  }
+  }
diff --git a/man/lfa_combine_sf_obj.Rd b/man/lfa_combine_sf_obj.Rd
new file mode 100644
index 0000000..9f6db1d
--- /dev/null
+++ b/man/lfa_combine_sf_obj.Rd
@@ -0,0 +1,29 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/combine_sf_obj.R
+\name{lfa_combine_sf_obj}
+\alias{lfa_combine_sf_obj}
+\title{Combine Spatial Feature Objects from Multiple GeoPackage Files}
+\usage{
+lfa_combine_sf_obj(paths, area_infos)
+}
+\arguments{
+\item{paths}{A character vector containing file paths to GeoPackage files with neighbor information.}
+
+\item{area_infos}{A data frame or list containing information about the corresponding detection areas, including "area" and "specie" columns.}
+}
+\value{
+A combined sf object with additional columns for area and specie information.
+}
+\description{
+This function reads spatial feature objects (sf) from multiple GeoPackage files and combines them into a single sf object.
+Each GeoPackage file is assumed to contain neighbor information for a specific detection area, and the resulting sf object
+includes additional columns indicating the corresponding area and species information.
+}
+\examples{
+# Assuming paths and area_infos are defined
+combined_sf <- lfa_combine_sf_obj(paths, area_infos)
+
+# Print the combined sf object
+print(combined_sf)
+
+}
diff --git a/man/lfa_find_n_nearest_trees.Rd b/man/lfa_find_n_nearest_trees.Rd
new file mode 100644
index 0000000..ccb755a
--- /dev/null
+++ b/man/lfa_find_n_nearest_trees.Rd
@@ -0,0 +1,30 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/find_n_nearest_trees.R
+\name{lfa_find_n_nearest_trees}
+\alias{lfa_find_n_nearest_trees}
+\title{Find n Nearest Trees}
+\usage{
+lfa_find_n_nearest_trees(trees, n = 100)
+}
+\arguments{
+\item{trees}{A sf object containing tree coordinates.}
+
+\item{n}{The number of nearest trees to find for each tree (default is 100).}
+}
+\value{
+A data frame with additional columns representing the distances to the n nearest trees.
+}
+\description{
+This function calculates the distances to the n nearest trees for each tree in the input dataset.
+}
+\examples{
+# Load tree data using lfa_get_detections() (not provided)
+tree_data <- lfa_get_detections()
+
+# Filter tree data for a specific species and area
+tree_data = tree_data[tree_data$specie == "pine" & tree_data$area == "greffen", ]
+
+# Find the 100 nearest trees for each tree in the filtered dataset
+tree_data <- lfa_find_n_nearest_trees(tree_data)
+
+}
diff --git a/man/lfa_get_detections.Rd b/man/lfa_get_detections.Rd
new file mode 100644
index 0000000..db15557
--- /dev/null
+++ b/man/lfa_get_detections.Rd
@@ -0,0 +1,36 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/get_detections.R
+\name{lfa_get_detections}
+\alias{lfa_get_detections}
+\title{Retrieve aggregated detection data for multiple species.}
+\usage{
+lfa_get_detections()
+}
+\value{
+A data frame containing aggregated detection data for multiple species.
+}
+\description{
+This function obtains aggregated detection data for multiple species by iterating
+through the list of species obtained from \code{\link{lfa_get_species}}. For each
+species, it calls \code{\link{lfa_get_detections_species}} to retrieve the
+corresponding detection data and aggregates the results into a single data frame.
+The resulting data frame includes columns for the species, tree detection data,
+and the area in which the detections occurred.
+}
+\examples{
+lfa_get_detections()
+
+# Retrieve aggregated detection data for multiple species
+detections_data <- lfa_get_detections()
+
+}
+\seealso{
+\code{\link{lfa_get_species}}, \code{\link{lfa_get_detections_species}}
+
+Other data retrieval functions: 
+\code{\link{lfa_get_species}()}
+}
+\concept{data retrieval functions}
+\keyword{aggregation}
+\keyword{data}
+\keyword{manipulation}
diff --git a/man/lfa_get_neighbor_paths.Rd b/man/lfa_get_neighbor_paths.Rd
new file mode 100644
index 0000000..379e4dd
--- /dev/null
+++ b/man/lfa_get_neighbor_paths.Rd
@@ -0,0 +1,22 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/get_neighbor_paths.R
+\name{lfa_get_neighbor_paths}
+\alias{lfa_get_neighbor_paths}
+\title{Get Paths to Neighbor GeoPackage Files}
+\usage{
+lfa_get_neighbor_paths()
+}
+\value{
+A character vector containing file paths to GeoPackage files for each detection area's neighbors.
+}
+\description{
+This function retrieves the file paths to GeoPackage files containing neighbor information for each detection area.
+The GeoPackage files are assumed to be named "neighbours.gpkg" and organized in a directory structure under the "data" folder.
+}
+\examples{
+# Get paths to neighbor GeoPackage files for all areas
+paths <- lfa_get_neighbor_paths()
+
+# Print the obtained file paths
+print(paths)
+}
diff --git a/man/lfa_get_species.Rd b/man/lfa_get_species.Rd
new file mode 100644
index 0000000..6b1e3e3
--- /dev/null
+++ b/man/lfa_get_species.Rd
@@ -0,0 +1,34 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/get_species.R
+\name{lfa_get_species}
+\alias{lfa_get_species}
+\title{Get a list of species from the data directory.}
+\usage{
+lfa_get_species()
+}
+\value{
+A character vector containing the names of species found in the "data" directory.
+}
+\description{
+This function retrieves a list of species by scanning the "data" directory
+located in the current working directory.
+}
+\examples{
+# Retrieve the list of species
+species_list <- lfa_get_species()
+
+}
+\references{
+This function relies on the \code{\link{list.dirs}} function for directory listing.
+}
+\seealso{
+\code{\link{list.dirs}}
+
+Other data retrieval functions: 
+\code{\link{lfa_get_detections}()}
+}
+\concept{data retrieval functions}
+\keyword{data}
+\keyword{file}
+\keyword{manipulation}
+\keyword{system}
diff --git a/man/lfa_save_all_neighbours.Rd b/man/lfa_save_all_neighbours.Rd
new file mode 100644
index 0000000..50d3761
--- /dev/null
+++ b/man/lfa_save_all_neighbours.Rd
@@ -0,0 +1,22 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/save_all_neighbours.R
+\name{lfa_save_all_neighbours}
+\alias{lfa_save_all_neighbours}
+\title{Save Neighbors for All Areas}
+\usage{
+lfa_save_all_neighbours(n = 100)
+}
+\arguments{
+\item{n}{The number of nearest trees to find for each tree (default is 100).}
+}
+\description{
+This function iterates through all detection areas, finds the n nearest trees for each tree,
+and saves the result to a GeoPackage file for each area.
+}
+\examples{
+# Save neighbors for all areas with default value (n=100)
+lfa_save_all_neighbours()
+
+# Save neighbors for all areas with a specific value of n (e.g., n=50)
+lfa_save_all_neighbours(n = 50)
+}