Compute forest loss per polygon in Google Earth Engine

Question

I am trying to compute the total forest loss based on the Hansen dataset in Google Earth Engine.

I would like to know the total number of pixels lost per polygon of a shapefile imported as a feature collection.

The code runs and the tasks appear on the task tab, but when I run it I get an error:

Error: Feature, argument 'metadata': Invalid type. Expected: Dictionary. Actual: FeatureCollection.

This is my code:

var table = ee.FeatureCollection("users/alejandrofeged/Colombian-map");
Map.addLayer(table,{},"Colombia")

var image = ee.Image("UMD/hansen/global_forest_change_2017_v1_5")
  .clipToCollection(table);

var lossImage = image.select(['loss']);
Map.addLayer(lossImage.updateMask(lossImage),
    {palette: ['FF0000']}, 'Loss');



Export.image.toDrive({
  image: lossImage,
  description: 'GFW-2000-2017',
  scale: 30,
  region: table,
  maxPixels: 8813288590
});


var means = lossImage.reduceRegions({
  collection: table,
  reducer: ee.Reducer.sum(),
  scale: 30,
});

// Print the first feature, to illustrate the result.
print(ee.Feature(means.first()));

var feature = ee.Feature(null, means);

// Wrap the Feature in a FeatureCollection for export.
var forestloss = ee.FeatureCollection([feature]);

// Export the FeatureCollection.
Export.table.toDrive({
  collection: forestloss,
  description: 'forestloss',
  fileFormat: 'CSV'
});

Answer 1

The function Image.reduceRegions returns a FeatureCollection, so exporting the complete collection would be:

// Export the FeatureCollection.
Export.table.toDrive({
  collection: means,
  description: 'forestloss',
  fileFormat: 'CSV'
});

And exporting only the first Feature would be:

var first = ee.Feature(means.first());
var forestloss = ee.FeatureCollection([first]);

// Export the FeatureCollection.
Export.table.toDrive({
  collection: forestloss,
  description: 'forestloss',
  fileFormat: 'CSV'
});

Finally, exporting a selected feature by its position in the collection:

var feat = 4;
var feature = ee.Feature(means.toList(means.size()).get(feat))
var forestloss = ee.FeatureCollection([feature]);

// Export the FeatureCollection.
Export.table.toDrive({
  collection: forestloss,
  description: 'forestloss',
  fileFormat: 'CSV'
});