```python
from flask import Flask, render_template, request, jsonify
import os
from PIL import Image
import numpy as np

app = Flask(__name__)

# Define the HTML template for the Tree Counter page
@app.route('/')
def index():
    return render_template('index.html')

# Define the API endpoint for uploading images
@app.route('/upload_image', methods=['POST'])
def upload_image():
    image = request.files['image']
    image.save('image.jpg')
    img = Image.open('image.jpg')
    width, height = img.size
    if width > 1024 or height > 1024:
        return jsonify({'message': 'Image is too large. Please crop it.'})
    else:
        # Simulate tree detection using YOLO8 model
        # Replace this with actual model implementation
        trees = np.random.randint(0, 100)
        return jsonify({'message': f'Number of Trees: {trees}'})

# Define the API endpoint for cropping images
@app.route('/crop_image', methods=['POST'])
def crop_image():
    image = request.files['image']
    image.save('image.jpg')
    img = Image.open('image.jpg')
    width, height = img.size
    # Simulate image cropping
    # Replace this with actual image cropping implementation
    cropped_img = img.crop((0, 0, 1024, 1024))
    cropped_img.save('cropped_image.jpg')
    return jsonify({'message': 'Image cropped successfully'})

if __name__ == '__main__':
    app.run(debug=True)