diff --git a/Doctrine/Tree.php b/Doctrine/Tree.php
new file mode 100644
index 000000000..245c0d9c7
--- /dev/null
+++ b/Doctrine/Tree.php
@@ -0,0 +1,43 @@
+<?php
+/*
+ *  $Id$
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.phpdoctrine.com>.
+ */
+/**
+ * Doctrine_Tree
+ *
+ * the purpose of Doctrine_Tree is to provide tree access 
+ * functionality for all records extending it
+ *
+ * @package     Doctrine ORM
+ * @url         www.phpdoctrine.com
+ * @license     LGPL
+ */
+abstract class Doctrine_Tree extends Doctrine_Record {
+    
+    abstract public function getLeafNodes();
+
+    abstract public function getPath();
+
+    abstract public function getDepth();
+
+    abstract public function removeNode();
+    
+    abstract public function addNode();
+}
+?>
diff --git a/Doctrine/Tree/NestedSet.php b/Doctrine/Tree/NestedSet.php
new file mode 100644
index 000000000..3131a1727
--- /dev/null
+++ b/Doctrine/Tree/NestedSet.php
@@ -0,0 +1,43 @@
+<?php
+/*
+ *  $Id$
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.phpdoctrine.com>.
+ */
+/**
+ * Doctrine_Tree_NestedSet
+ *
+ * the purpose of Doctrine_Tree_NestedSet is to provide NestedSet tree access
+ * strategy for all records extending it
+ *
+ * @package     Doctrine ORM
+ * @url         www.phpdoctrine.com
+ * @license     LGPL
+ */
+class Doctrine_Tree_NestedSet extends Doctrine_Record {
+
+    public function getLeafNodes() { }
+
+    public function getPath() { }
+
+    public function getDepth() { }
+
+    public function removeNode() { }
+    
+    public function addNode() { }
+}
+?>
diff --git a/Doctrine/Tree/PathModel.php b/Doctrine/Tree/PathModel.php
new file mode 100644
index 000000000..dfdeaec18
--- /dev/null
+++ b/Doctrine/Tree/PathModel.php
@@ -0,0 +1,44 @@
+<?php
+/*
+ *  $Id$
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.phpdoctrine.com>.
+ */
+/**
+ * Doctrine_Tree_PathModel
+ *
+ * the purpose of Doctrine_Tree_NestedSet is to provide PathModel tree access
+ * strategy for all records extending it
+ *
+ * @package     Doctrine ORM
+ * @url         www.phpdoctrine.com
+ * @license     LGPL
+ */
+class Doctrine_Tree_PathModel extends Doctrine_Record {
+
+    public function getLeafNodes() { }
+
+    public function getPath() { }
+
+    public function getDepth() { }     
+
+    public function removeNode() { }
+    
+    public function addNode() { }
+
+}
+?>